How to Shoot “Deep-Sky with Your DSLR”


KSPage-Feb7We’ve embarked upon a new project to produce a comprehensive tutorial on deep-sky imaging with DSLR cameras.

This past week we launched a new KickStarter campaign to fund the production of a new multi-hour video course on how to capture deep-sky objects using entry-level telescope gear and DSLR cameras.

The emphasis in the course will be on techniques for taking and processing publication-quality images as simply and easily as possible.

A Frosty Telescope Shooting Andromeda

The final video course will consist of several programs, including a video of one of our annual “Deep-Sky with Your DSLR” workshops presented locally here in Alberta. We’ve often had requests for a video version of those workshops, for those who cannot attend in person.

This is it! Here’s a short preview of some of the content.

 

We include the Workshop video, but we supplement it with much more: with video segments shot in the field by day and by night, showing how to setup and use gear, and shot in the studio showing how to process images.

Deep-Sky Photo Session in the Backyard

While much of the content has been shot and edited, there’s more to do yet. Thus our KickStarter campaign to complete the funding and production. Backers of the project through KickStarter will get the final videos at a substantial discount off the final retail price.

All the details are on the project’s KickStarter page. Click through for the listing of course content, and options for funding levels. An FAQ page answers many of the common questions.

A week into the campaign and we’re just over 50% funded, but we have a way to go yet!

M31 with Orion 80mm Apo and Celestron AVX Mount (Multiple Exposu

We hope you’ll consider backing our project, which we think will be unique on the market.

Clear skies!

— Alan, February 7, 2019 / © 2019 / AmazingSky.com 

 

 

 

Testing the Canon 6D Mark II for Deep-Sky


6D MkII on Cygnus

Following up on my earlier tests, I compare the new Canon 6D MkII camera to earlier Canon full-frame models in long, tracked exposures of the Milky Way.

A month ago I published tests of the new Canon 6D MkII camera for nightscape images, ones taken using a fixed tripod in which exposures usually have to be limited to no longer than 30 to 60 seconds, to prevent star trailing.

Despite these short exposures, we still like to extract details from the dark shadows of the scene, making nightscape images a severe test of any camera.

I refer you to my August 9, 2017 blog Testing the Canon 6D MkII for Nightscapes for the results. The 6D MkII did not fare well.

Here I test the 6D MkII for what, in many respects, is a less demanding task: shooting long exposures of deep-sky objects, the Milky Way in Cygnus in this case.

Why is this an easier task? The camera is now on a tracking mount (I used the new Sky-Watcher Star Adventurer Mini) which is polar aligned to follow the rotation of the sky. As such, exposures can now be many minutes long if needed. We can give the camera sensor as much signal as the darkness of the night sky allows. More signal equals less noise in the final images.

In addition, there are no contrasty, dark shadows where noise lurks. Indeed, the subjects of deep-sky images are often so low in contrast, as here, they require aggressive contrast boosting later in processing to make a dramatic image.

While that post-processing can bring out artifacts and camera flaws, as a rule I never see the great increase in noise, banding, and magenta casts I sometimes encounter when processing short-exposure nightscape scenes.


6D MkII at Four ISOs
The Canon 6D MkII at four typical ISO speeds in tracked exposures.

6D at Four ISOs
The original Canon 6D at four typical ISO speeds in tracked exposures.

5D MkII at Four ISOs
A Canon 5D MkII that has been filter-modified at four typical ISO speeds in tracked exposures.
For this test, I shot the same region of sky with the same 35mm lens L-Series lens at f/2.2, using three cameras:

• Canon 6D MkII (2017)

• Canon 6D (2012)

• Canon 5D MkII (2008)

Note that the 5D MkII has been “filter-modified” to make its sensor more sensitive to the deep red wavelengths emitted by hydrogen gas, the main component of the nebulas along the Milky Way. You’ll see how it picks up the red North America Nebula much better than do the two off-the-shelf “stock” cameras. (Canon had their own factory-modified “a” models in years past: the 20Da and 60Da. Canon: How about a 6D MkIIa?)

I shot at four ISO speeds typical of deep-sky images: 800, 1600, 3200, and 6400.

Exposures were 4 minutes, 2 minutes, 1 minute, and 30 seconds, respectively, to produce equally exposed frames with a histogram shifted well to the right, as it should be for a good signal-to-noise ratio.

Noisy deep-sky images with DSLR cameras are usually the result of the photographer underexposing needlessly, often in the mistaken belief that doing so will reduce noise when, in fact, it does just the opposite.

The above set of three images compares each of the three cameras at those four ISO speeds. In all cases I have applied very little processing to the images: only a lens correction, some sharpening, a slight contrast and clarity increase, and a slight color correction to neutralize the background sky.

However, I did not apply any luminance noise reduction. So all the images are noisier than what they would be in a final processed image.

Even so, all look very good. And with similar performance.

All frames were shot with Long Exposure Noise Reduction (LENR) on, for an automatic dark frame subtraction by the camera. I saw no artifacts from applying LENR vs. shots taken without it.

The 6D and 6D MkII perhaps show a little less noise than the old 5D MkII, as they should being newer cameras.

The 6D MkII also shows a little less pixelation on small stars, as it should being a 26 megapixel camera vs. 20 to 21 megapixels for the older cameras. However, you have to examine the images at pixel-peeping levels to see these differences. Nevertheless, having higher resolution without the penalty of higher noise is very welcome.


3 Canons at ISO 1600
The three cameras compared at ISO 1600. Note the histogram and region of the frame we are examining up close.

3 Canons at ISO 3200
The three cameras compared at ISO 3200. Note the histogram and region of the frame we are examining up close.

3 Canons at ISO 6400
The three cameras compared at ISO 6400. Note the histogram and region of the frame we are examining up close.
Above, I show images from the three cameras side by side at ISOs 1600, 3200, and 6400. It is tough to tell the difference in noise levels, the key characteristic for this type of astrophotography.

The new 6D MkII shows very similar levels of noise to the 6D, perhaps improving upon the older cameras a tad.

Because images are well-exposed (note the histogram at right), the 6D MkII is showing none of the flaws of its lower dynamic range reported elsewhere.

That’s the key. The 6D MkII needs a well-exposed image. Given that, it performs very well.


3 Canons Stacked & Processed
The three cameras in stacked and processed final images.
This version shows the same images but now with stacked frames and with a typical level of processing to make a more attractive and richer final image. Again, all look good, but with the modified camera showing richer nebulosity, as they do in deep-sky images.

The lead image at the very top is a final full-frame image with the Canon 6D MkII.


As such, based on my initial testing, I can recommend the Canon 6D MkII (and plan to use it myself) for deep-sky photography.

Indeed, I’ll likely have the camera filter-modified to replace my vintage yet faithful 5D MkII for most of my deep-sky shooting. The 6D MkII’s tilting LCD screen alone (a neck, back, and knee saver when attached to a telescope!) makes it a welcome upgrade from the earlier cameras.

The only drawback to the 6D MkII for deep-sky work is its limited dark frame buffer. As noted in my earlier review, it can shoot only three Raw files in rapid succession with Long Exposure Noise Reduction turned on. The 5D MkII can shoot five; the 6D can shoot four. (A 6D MkIIa should have this buffer increased to at least 4, if not 8 images.)

I make use of this undocumented feature all the time to ensure cleaner images in long deep-sky exposures, as it produces and subtracts dark frames with far greater accuracy than any taken later and applied in post-processing.


I hope you’ve found this report of interest.

With the 6D MkII so new, and between smoky skies and the interference of the Moon, I’ve had only one night under dark skies to perform these tests. But the results are promising.

For more tips on deep-sky imaging and processing see my pages on my website:

Ten Tips for Deep-Sky Images

Ten Steps to Deep-Sky Processing

Thanks and clear skies!

— Alan, September 7, 2017 / © 2017 Alan Dyer / amazingsky.com

 

Toward the Centre of the Galaxy


Toward the Centre of the Galaxy

From southern latitudes the most amazing region of the sky shines overhead late on austral autumn nights. 

There is no more spectacular part of the Milky Way than the regions around its galactic centre. Or at least in the direction of the galaxy’s core.

We can’t see the actual centre of the Galaxy, at least not with the cameras and telescopes at the disposal of amateur photographers such as myself.

It takes large observatory telescopes equipped with infrared cameras to see the stars orbiting the actual centre of the Milky Way. Doing so over many years reveals stars whipping around an invisible object with an estimated 4 million solar masses packed into the volume no larger than the solar system. It’s a black hole.

By comparison, looking in that direction with our eyes and everyday cameras, we see a mass of stars in glowing clouds intersected by lanes of dark interstellar dust.

The top image shows a wide view of the Milky Way toward the galactic centre, taking in most of Sagittarius and Scorpius and their incredible array of nebulas, star clusters and rivers of dark dust, all located in the dense spiral arms between us and the galactic core.

Starclouds and Stardust – Mosaic of the Galactic Centre
This is a mosaic of 6 segments, each segment being a stack of 4 x 3-minute exposures at f/2.8 with the 135mm Canon L-Series

Zooming into that scene reveals a panoramic close-up of the Milky Way around the galactic centre, from the Eagle Nebula in Serpens, at left, to the Cat’s Paw Nebula in Scorpius, at right.

This is the richest hunting ground for stargazers looking for deep-sky wonders. It’s all here, with field after field of telescopic and binocular sights in an area of sky just a few binocular fields wide.

The actual galactic core area is just right of the centre of the frame, above the bright Sagittarius StarCloud.

Centre of the Galaxy Area
This is a stack of 5 x 5 minute exposures with the Borg 77mm f/4 astrograph and filter-modified Canon 5D MkII at ISO 1600, taken from Tibuc Cottage near Coonabarabran, NSW, Australia.

Zooming in again shows just that region of sky in an even closer view. The contrast between the bright star fields at left and the dark intervening dust at right is striking even in binoculars – perhaps especially in binoculars.

The visual impression is of looking into dark canyons of space plunging off bright plateaus of stars.

In fact, it is just the opposite. The dark areas are created by dust much closer to us, hiding more distant stars. It is where the stars are most abundant, in the dust-free starclouds, that we see farthest into the galaxy.

In the image above the galactic centre is at right, just above the small diffuse red nebula. In that direction, some 28,000 light years away, lurks the Milky Way’s monster black hole.

Milky Way Overhead Through Trees
This is a stack of 5 x 6-minute tracked exposures with the 15mm fish-eye lens at f/4 and Canon 5D MKII at ISO 1600. The trees appear to be swirling around the South Celestial Pole at lower right above the Cottage.

To conclude my tour of the galactic centre, I back out all the way to see the entire sky and the Milky Way stretching from horizon to horizon, with the galactic centre nearly overhead in this view from 3 a.m. earlier this week.

Only from a latitude of about 30° South can you get this impressive view, what I consider one of the top “bucket-list” sights the sky has to offer.

– Alan, April 17, 2016 / © 2016 Alan Dyer / www.amazingsky.com

 

The Wonder-Filled Winter Sky


Mosaic of the Wonder-filled Winter Milky Way

The sky of December contains an amazing array of bright stars and deep-sky delights.

At this time of year we peer out toward the edge of our Galaxy, in the direction opposite to what we see in July and August. Even though we are looking away from the centre of our Galaxy, the Milky Way at this time of year contains a stunning collection of sights – for the naked eye, binoculars or a telescope.

I can’t list them all here, but most are in the lead image above! The image is a mosaic of the northern winter Milky Way, including the brilliant stars and constellations in and around Orion the Hunter.

The Milky Way extends from Perseus in the north at top, to Canis Major in the south at bottom. Throughout the scene are dark lanes and dust clouds, such as the Taurus Dark Clouds at upper right.

The Milky Way is dotted with numerous red “hydrogen-alpha” regions of emission nebulosity, such as the bright Rosette Nebula at lower left and the California Nebula at upper right. The curving arc of Barnard’s Loop surrounds the east side of Orion. Orion is below centre, with Sirius, the night sky’s brightest star, at lower left.

The constellation of Taurus is at upper right and Gemini at upper left. Auriga is at top and Perseus at upper right.

There’s an unusually bright area in Taurus just right of centre in the mosaic which I thought might be an image processing artifact. No. It’s the Gegenschein – a glow of sunlight reflected off comet dust directly opposite the Sun.

Two highlights of this sky that are great regions for binoculars are the Hyades cluster in Taurus ….

The Hyades Cluster with Aldebaran
The Hyades open star cluster in Taurus with the bright star Aldebaran, not a part of the cluster iteslf. The smaller and more distant cluster NGC 1647 is at left. This is a telephoto lens image taking in a field similar to binoculars, and is a stack of 5 x 2.5-minute exposures with the 135mm lens at f/2 and Canon 5D MkII camera at ISO 800, plus two other exposures taken through the Kenko Softon filter to add the star glows. Taken from Quailway Cottage on Dec 7, 2015 using the iOptron Sky-Tracker.

…and the Belt and Sword of Orion.

The Hyades – the face of Taurus – is one of the nearest and therefore largest open star clusters.

Orion the Hunter, who battles Taurus in the sky, contains the famous Orion Nebula, here overexposed in order to bring out the much fainter nebulosity in the region.

The magenta and blue arcs in the image below are photographic targets, but the bright Orion Nebula in Orion’s Sword is easy in binoculars, shining below the trio of his Belt Stars.

Orion Belt and Sword Mosaic
A mosaic of the Sword and Belt region of Orion the Hunter, showing the diverse array of colourful nebulas in the area, including: curving Barnard’s Loop, the Horsehead Nebula below the left star of the Belt, Alnitak, and the Orion Nebula itself as the bright region in the Sword. Also in the field are numerous faint blue reflection nebulas. The reflection nebula M78 is at top embedded in a dark nebula, and the pinkish NGC 2024 or Flame Nebula is above Alnitak. The bright orange-red star at far right is W Orionis, a type M4 long-period variable star. This is a 4-panel mosaic with each panel made of 5 x 2.5-minute exposures with the 135mm Canon L-series telephoto wide open at f/2 and the filter-modified Canon 5D MkII at ISO 1250. The night was somewhat hazy which added natural glows on the stars. No filter was employed here. The camera was on the iOptron Sky-Tracker for tracking but no guiding. Shot from outside Quailway Cottage near Portal, Arizona, Dec 7, 2015. All stacking and stitching performed in Photoshop CC 2015. Stacking done with median combine stack mode to eliminate geosat trails through the fields.

For us in the northern hemisphere, Orion and company are winter sights. But for those down under, in the southern hemisphere, this is the summer sky. So pardon the northern chauvinism in the title!

Either way, on a dark, moonless night, get out and explore the sky around Orion.

TECHNICAL:

I shot the segments for the main mosaic at top on a very clear night on December 5, 2015 from the Quailway Cottage at Portal, Arizona. This is a mosaic of 8 segments, in two columns of 4 rows, with generous overlap. Each segment was made of 4 x 2.5-minute exposures stacked with mean combine stack mode to reduce noise, plus 2 x 2.5-minute exposures taken through the Kenko Softon filter layered in with Lighten belnd mode to add the star glows. Each segment was shot at f/2.8 with the original 35mm Canon L-series lens and the filter-modified (by Hutech) Canon 5D MkII at ISO 1600, riding on the iOptron Sky-Tracker. All stacking and stitching in Photoshop CC 2015. The soft diffusion filter helps bring out the star colors in this area of sky rich in brilliant giant stars.

— Alan, December 11, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Shooting the Heart Nebula


Testing the Nikon D810a

Last night I shot into the autumn Milky Way at the Heart Nebula.

I’m currently just finishing off a month of testing the new Nikon D810a camera, a special high-end DSLR aimed specifically at astrophotographers.

I’ll post a more thorough set of test shots and comparisons in a future blog, but for now here are some shots from the last couple of nights.

Above is the setup I used to shoot the image below, shot in the act of taking the image below!

The Nikon is at the focus of my much-loved TMB 92mm refractor, riding on the Astro-Physics Mach One mount. The mount is being “auto-guided” by the wonderful “just-press-one-button” SG-4 auto-guider from Santa Barbara Instruments. The scope is working at a fast f/4.4 with the help of a field flattener/reducer from Borg/AstroHutech.

I shot a set of 15 five-minute exposures at ISO 1600 and stacked, aligned and averaged them (using mean stack mode) in Photoshop. I explain the process in my workshops, but there’s also a Ten Steps page at my website with my deep-sky workflow outlined.

IC 1805 Heart Nebula (92mm D810a)
The Heart Nebula, IC 1805, in Cassiopeia, with nebula NGC 896 at upper right and star cluster NGC 1027 at left of centre. This is a stack of 15 x 5-minute exposures with the Nikon D810a as part of testing, at ISO 1600, and with the TMB 92mm apo refractor at f/4.4 with the Borg 0.85x field flattener. Taken from home Nov 29, 2015.

The main advantage of Nikon’s special “a” version of the D810 is its extended red sensitivity for a capturing just such objects in the Milky Way, nebulas which shine primarily in the deep red “H-alpha” wavelength emitted by hydrogen.

It works very well! And the D810a’s 36 megapixels really do resolve better detail, something you appreciate in wide-angle shots like this one, below, of the autumn Milky Way.

It’s taken with the equally superb 14-24mm f/2.8 Nikkor zoom lens. Normally, you would never use a zoom lens for such a demanding subject as stars, but the 14-24mm is stunning, matching or beating the performance of many “prime” lenses.

The Autumn Milky Way (Perseus to Cygnus)
The Milky Way from Perseus, at left, to Cygnus, at right, with Cassiopeia (the “W”) and Cepheus at centre. Dotted along the Milky Way are various red H-alpha regions of glowing hydrogen. The Andromeda Galaxy, M31, is at botton. The Double Cluster star cluster is left of centre. Deneb is the bright star at far right, while Mirfak, the brightest star in Perseus, is at far left. The Funnel Nebula, aka LeGentil 3, is the darkest dark nebula left of Deneb. This is a stack of 4 x 1-minute exposures at f/2.8 with the Nikkor 14-24mm lens wide open, and at 24mm, and with the Nikon D810a red-sensitive DSLR, at ISO 1600. Shot from home, with the camera on the iOptron Sky-Tracker.

The D810a’s extended red end helps reveal the nebulas along the Milky Way. The Heart Nebula, captured in the close-up at top, is just left of centre here, left of the “W” forming Cassiopeia.

The Nikon D810a is a superb camera, with low noise, high-resolution, and features of value to astrophotographers. Kudos to Nikon for serving our market!

– Alan, November 30, 2015 / © 2015 Alan Dyer / www.amazingsky.com

 

Both the Heart and Soul of Cassiopeia


Heart & Soul Nebulas (IC 1805 and IC 1848) in Cassiopeia

Here are both the heart and the soul of Cassiopeia the Queen.

Two days ago I posted an image of the Soul Nebula. Now, here is the matching Heart Nebula, in a mosaic of the glorious region of the Milky Way called the Heart and Soul Nebulas located in the constellation of Cassiopeia.

They are otherwise respectively called IC 1805 and IC 1848. Amid the swirls of nebulosity are numerous clusters of stars, such as NGC 1027 just above centre. The separate patch of nebulosity at upper right is NGC 896.

I shot the frames for this 3-segment mosaic over two nights, with one segment taken from the frames that made up the previous post. Plus I shot two others to span the region of the Milky Way that is about seven degrees long, a binocular field.

Each of the 3 segments is a stack of 12 frames, with each frame a 6-minute exposure. I used the filter-modified Canon 5D MkII and shot through the TMB 92mm apo refractor at f/4.4. All processing was in Photoshop, including the mosaic assembly.

In all, it’s the best image I’ve taken of this much-shot area of the sky. It really brings out the diversity in star colours, and sky colours, from the dusty orange-brown region at left, to the inky dark dustless region at far right.

– Alan, November 18 2014 / © 2014 Alan Dyer

 

The Soul of Cassiopeia


IC 1848, the Soul Nebula, in Cassiopeia

The Soul Nebula glows from within the constellation of Cassiopeia the Queen.

I shot this image last night, capturing an object prosaically known as IC 1848, but more popularly called the Soul Nebula.

It is often depicted framed with a companion nebula just “off camera” here to the right, called the Heart Nebula. Thus they are the Heart and Soul. Both shine on the eastern side of Cassiopeia the Queen.

Here I’m framing just the Soul, taking in some of the faint nebulosity to the left of the main nebula, including a tiny object called IC 289, a star-like planetary nebula at upper left.

I like this image for its variety of subtle colours, not only the reds and magentas in the bright nebula, but also in the dark sky around it from dim dust adding faint yellows, browns and even a touch of green.

The Soul Nebula lies 6,500 light years away in the Perseus Arm, the next spiral arm out from ours in the Milky Way. On northern autumn nights this region of the sky and Milky Way lies high overhead.

For the technically minded:

The image is a stack of 20 six-minute exposures, taken with a filter-modified Canon 5D Mark II at ISO 800. I was shooting through one of my favourite telescopes for deep-sky photography, the TMB (Thomas M. Back-designed) 92mm apo refractor, working at a fast f/4.4 using a Borg 0.85x field flattener and focal reducer.

I used one of Noel Carboni’s “Astronomy Tools” Photoshop actions to add the “diffraction spikes” on the stars. They are artificial (refractors don’t produce spikes on stars) but they add a photogenic touch to a rich starfield.

I shot this from the backyard of my New Mexico winter home.

– Alan, November 16, 2014 / © 2014 Alan Dyer

Truly Interstellar


M26 Open Cluster and NGC 6712 Globular Cluster

We gaze into the interstellar depths of the Milky Way through uncountable stars.

In this telescopic scene we look toward the Scutum Starcloud, and next spiral arm in from ours as we gaze toward the core of the Galaxy.

The field is packed with stars, seemingly crowded together in interstellar space. In fact, light years of empty space separate the stars, even in crowded regions of the Milky Way like this.

Two dense clusters of stars stand out like islands in the sea of stars. At lower right is Messier 26, an open cluster made of a few dozen stars. Our young Sun probably belonged to a similar family of stars billions of years ago. M26 lies 5,200 light years away.

At upper left is a condensed spot of light, made of hundreds of thousands of density packed stars in the globular cluster known only as NGC 6712. Though much larger and denser than M26, NGC 6712 appears as a tiny spot because of its remoteness – 23,000 light years away, a good part of the distance toward the centre of the Galaxy.

Look carefully (and it may not be visible on screen) and you might see a small green smudge to the left of NGC 6712. That’s a “planetary nebula” called IC 1295. It’s the blown off atmosphere of an aging Sun-like star. It’s what our Sun will become billions of years from now.

At top is a vivid orange-red star, S Scuti, a giant pulsating star nearing the end of its life.

A truly interstellar scene.

– Alan, November 9, 2014 / © 2014 Alan Dyer

 

 

Mars and M22


Mars and M22 Cluster

Mars shines near the globular star cluster Messier 22 in Sagittarius.

This week Mars has been passing near one of the brightest globular star clusters, M22. I caught the pair tonight, November 8, as they sank into the southwestern sky.

The two form a contrasting pair, with red Mars now 260 million kilometres away, far enough that its light takes 13 minutes to reach Earth. However, blue M22 lies so far away, toward the galactic core, that its light take 10,000 years to reach Earth.

Mars appeared closer to M22 earlier this week but tonight was the first night with a narrow window of dark sky between twilight and moonrise, allowing me to shoot the pair.

I shot the image through a telescope with a short focal length of 400mm, taking in a field of about 5 by 3 degrees, the field of high-power binoculars. The image is a stack of eight 2-minute exposures at f/4.5 with the TMB 92mm refractor and Canon 6D at ISO 800.

– Alan, November 8, 2014 / © 2014 Alan Dyer

Nebulas, Clusters and Starfields, Oh My!


Centre of the Galaxy Mosaic

There’s no more spectacular region of the sky than the Milky Way toward the centre of the Galaxy.

What a perfect night it was last night. After moonset between 2 and 3:30 a.m. I shot a series of images around the centre of the Galaxy area and stitched them into a big mosaic of the Milky Way.

The scene takes in the Milky Way from the Eagle and Swan nebulas at top left, down to the Messier 6 and 7 open clusters in Scorpius at bottom. Standing out is the large pink Lagoon Nebula left of centre and the huge region of dark dusty nebulosity popularly called the Dark Horse at right of centre. It’s made of smaller dark nebulas such as the Pipe Nebula and tiny Snake Nebula.

At upper left is the bright Small Sagittarius Starcloud, aka Messier 24, flanked by the open clusters M23 and M25. There are a dozen or more Messier objects in this region of sky.

The actual centre of the Milky Way is obscured by dark dust but lies in the direction just below the centre of the frame, amid one of the bright star clouds that mark this amazing region of sky.

I shot the images for this mosaic from a site near Portal, Arizona, using a 135mm telephoto lens and filter-modified Canon 5D Mark II riding on an iOptron SkyTracker to follow the stars. The mosaic is made of 6 panels, each a stack of five 3-minute exposures. They were all stacked and stitched in Photoshop CC. The full version is 8000 by 9000 pixels and is packed with detail.

I think the result is one of the best astrophotos I’ve taken! It sure helps to have Arizona skies!

– Alan, May 5, 2014 / © 2014 Alan Dyer

 

 

Our Neighbour Galaxy, the Large Magellanic Cloud


Large Magellanic Cloud (77mm Borg & 5DII)

One of our nearest galactic neighbours contains an astonishing collection of nebulas and star clusters.

This is the money shot — top of my list for targets on this trip to Australia. This is the Large Magellanic Cloud, a satellite galaxy of our Milky Way. At “just” 160,000 light years away, the LMC is in our galactic backyard. Being so close, even the small 77mm telescope I used to take this image resolves numerous nebulas, star clusters, and a mass of individual stars. The image actually looks “noisy” from being filled with so many stars.

I’ve oriented and framed the Cloud to take in most of its main structure and objects. One can spend many nights just visually exploring all that the LMC contains. It alone is worth the trip to the southern hemisphere.

At left is the massive Tarantula Nebula, a.k.a. NGC 2070. At upper right is the LMC’s second best nebula, the often overlooked NGC 1763, also known as the LMC Lagoon. In between are many other magenta and cyan tinted nebulas.

I’ve shot this object several times but this is my best shot so far I think, and my first with this optical system in several years.

I used a Borg 77mm aperture “astrograph,” a little refractor telescope optimized for imaging. It is essentially a 330mm f/4 telephoto lens, but one that is tack sharp across the entire field, far outperforming any camera telephoto lens.

This shot is a stack of six 10-minute exposures at ISO 800 with the filter-modified Canon 5D MkII camera. The autoguider worked perfectly. And yet, I shot this in clear breaks between bands of clouds moving though last night. The night was humid but when the sky was clear it was very clear.

Next target when skies permit: the Vela Supernova Remnant.

– Alan, March 25, 2014 / © 2014 Alan Dyer

 

A Dreamy Carina Nebula


Carina Nebula in Haze (77mm 5DII)

The Carina Nebula glows among the colourful southern stars.

I’ve shot this field many times over the years in visits to the southern hemisphere but never with a result quite like this. Last night the sky was hazy with high cloud but I shot anyway. The result is a “dreamy” rendition of the Carina Nebula and its surrounding clusters of stars. At upper left is the Football Cluster, NGC 3532, while at upper right is the Gem Cluster, NGC 3293.

As with my previous post, the haze brings out the star colours, filling the field with pastel shades. It is one of the finest fields in the sky, worth the trip down under.

Alas, skies have clouded up tonight with only a few bright stars and Mars shining through. And the forecast is for rain for the next few days. So I may get lots of writing done at my Aussie retreat.

As a technical note: I shot this with the little 77mm Borg Astrograph, essentially a 300mm f/4 telephoto lens that is tack sharp across a full frame camera, like the Canon 5D MkII I used here. It was riding on my Astro-Physics 400 mount and guided flawlessly with the Santa Barbara SG4 auto-guider. The image is a stack of four 8-minute exposures. All the gear, much of it stored here in Australia between my visits, is working perfectly.

– Alan, March 23, 2014 / © 2014 Alan Dyer

 

The Pleiades – The Stellar Seven Sisters


M45, the Pleiades Cluster (92mm 5DII)

The stars of the Pleiades sit amid a dusty sky in Taurus.

These are the famous Seven Sisters of Greek legend, known as the Pleiades. They are the daughters of Atlas and Pleione, who are also represented by stars in the cluster. Many cultures around the world tell stories about these stars, but in Greek tradition their appearance signalled the summer sailing season in the Mediterranean. The Pleiades first appear at sunset in the eastern evening sky in autumn and put in their last appearance in the western sky in spring.

One story has it they were placed in the sky to recognize their devotion to their father Atlas and his unending labour in holding up the heavens. They are the half-sisters of the Hyades, another nearby cluster of stars in Taurus. Other stories describe the Pleiades as the Seven Doves that carried ambrosia to the infant Zeus.

A seldom-used name now for this cluster is the Atlantides, from the plural form of Atlas, their father. Thus, these sisters gave their name to the Atlantic Ocean, a vast and uncharted sea until the 16th century. The term “atlas,” first used by Mercator for a book of maps, comes not from the Pleiades’ father but from a real-life king in Morocco who supposedly made one of the first celestial globes.

I shot this portrait of the Sisters a few nights ago, stacking a set of five 15-minute exposures with the TMB 92mm refractor and Canon 5D MkII at ISO 800. I processed the image to bring out the faint clouds of dust that pervade the area.

The Pleiades are passing through dust clouds in Taurus and lighting them up. The stars are embedded in dust, lit blue by the light of the hot stars. But even farther out you can see wisps of dust faintly illuminated by the light of the Pleiades.

The stars are thought to be about 100 million years old, quite young as stars go. They formed together in a massive nebula that has long since dissipated, and will travel together for another few hundred million years until the sister stars go their own way around the Galaxy. The stellar family that gave rise to so many legends around the world will be scattered to the stars.

– Alan, October 12, 2013 / © 2013 Alan Dyer

A Star-Filled Scene in Cassiopeia


M52 & NGC 7635 Bubble Nebula (92mm 5DII)

A star cluster and nebulas highlight a glorious starfield in Cassiopeia.

I shot this three nights ago on a very clear autumn evening. The telescope field takes in the star cluster Messier 52 at upper left, a cluster of 200 stars about 5000 light years away. It is one of the best objects of its class for viewing in small telescopes. Charles Messier found it in 1774 as part of his quest to catalog objects that might be mistaken for comets.

The brightest area of nebulosity below M52 is the Bubble Nebula, aka NGC 7635, found in 1787 by William Herschel. It’s an area of star formation marked by a central bubble of gas (just visible on the scale of my photo) being blown by the winds from a hot central star. The Bubble can be seen in amateur telescopes but is a tough target to spot.

Above the Bubble is a small bright nebula, NGC 7538.

Below the Bubble lies a larger claw-like nebula known only as Sharpless 2-157, an object that shows up only in photos.

In all, it’s a complex and beautiful field, set in the constellation of Cassiopeia the Queen.

A footnote for the technically minded: This is a stack of 5 x 15 minute exposures with a filter-modified Canon 5D MkII at ISO 800 shooting through a TMB 92mm apo refractor at f/4.8, mounted on an Astro-Physics Mach 1 mount guided by a Santa Barbara SG-4 autoguider.

– Alan, October 11, 2013 / © 2013 Alan Dyer

 

The Veil Nebula in Cygnus


NGC 6960 & 6992-5 Veil Nebula (92mm 5DII)

This is what’s left of a star that exploded thousands of years ago.

I shoot this object every year or two, so this is my 2013 take on the Veil Nebula. For last year’s see Star Death Site, a post from September 2012.

The Veil Nebula is a supernova remnant. The lacework arcs are what’s left of a massive star that blew itself to bits in historic times. This object, one of the showpieces of the summer sky for telescope users, is now high overhead at nightfall, off the east wing of Cygnus the swan.

I shot this a couple of nights ago using a 92mm-aperture refractor that provides a wide field of view to easily frame the 3-degree-wide extent of the nebula. The image is a stack of five 15-minute exposures with a filter-modified (i.e. red sensitive) Canon 5D MkII camera at ISO 800. Stacking the images helps reduce noise.

The colours in this object make it particularly photogenic, with a contrast of magenta and cyan. At right, a sharp-edged area of obscuring interstellar dust tints the sky brown and dims the stars.

– Alan, October 9, 2013 / © 2013 Alan Dyer

The Cocoon Nebula in Cygnus


Cocoon Nebula IC 5146 (92mm 5DII)

A cocoon of glowing gas sits at the tip of a dark cloud of interstellar dust.

It’s been months since I’ve shot more “traditional” astrophotos, meaning images of deep-sky objects through telescopes. But the last couple of nights have been excellent, and well-timed to the dark of the Moon.

This is the Cocoon Nebula in Cygnus, aka IC 5146. It is a cloud of gas about 4,000 light years away where new stars are forming. They are lighting up the gas to glow with incandescent pink colours.

The Cocoon sits at the end of snake-like dark nebula known as Barnard 168 which, in the eyepiece of a telescope, is usually more obvious than the subtle bright nebula. Photos like mine here, with long exposures and boosted contrast and colours, make nebulas look much brighter and more colourful than they can ever appear to the eye.

For the technically curious, I shot this with a 92mm diameter apochromatic refractor, the TMB 92, and a Borg 0.85x flattener/reducer, a combination that gives a fast f-ratio of f/4.8 with a very flat wide field. I also used my now-vintage filter-modified Canon 5D MkII at ISO 800. This is a stack of five 12-minute exposures, registered and median-combined in Photoshop to smooth out noise. All processing was with Adobe Camera Raw and Photoshop CC. The telescope was on an Astro-Physics Mach 1 mount, flawlessly autoguided with an SBIG SG-4 autoguider.

– Alan, October 6, 2013 / © 2013 Alan Dyer

 

King and Queen of the Sky


Cassiopeia and Cepheus (50mm 5DII) Sept 29, 2013

Cassiopeia and Cepheus reign over the autumn sky amid the Milky Way.

This is a photo from last night’s shoot, taken on a very clear autumn night with the Milky Way prominent across the sky. I shot sets of constellation images, among them this one framing Queen Cassiopeia and King Cepheus.

Cassiopeia is the well-known “W” pattern at lower left. Cepheus is harder to pick out – he’s a crooked square at right, topped by a tall triangle, like a child’s drawing of a house.

The Milky Way runs across the frame, peppered with red nebulas, from IC 1396 at far right in the bottom of Cepheus, to the NGC 7822 complex at centre, and the IC 1805 complex at far left. Lots of smaller nebulas dot the scene. At far left is the Double Cluster, two adjacent clumps of stars in the outer Perseus Arm of the Milky Way. Most of the deep-sky objects in this frame lie thousands of light years away in the next spiral arm out from the one we live in, or in the space between the two arms.

Most of the bright stars here are young blue stars. But a couple of exceptions stand out: yellow Shedar (or Alpha Cassiopeiae, the bottommost star in the W and an orange giant), and red Mu Cephei, at far right bordering the round IC 1396 nebula. That star is also known as Herschel’s Garnet Star. It is a red supergiant star 1400 times larger than our Sun and one of the most luminous stars in the catalog.

– Alan, September 30, 2013 / © 2013 Alan Dyer

 

Star-Making Clouds in Cygnus


Cygnus Nebulosity (135mm 5DII)

The centre of Cygnus is laced with an intricate complex of glowing gas clouds.

This is another shot from earlier this week, under ideal skies, in a view looking straight up into Cygnus the Swan. This is a telephoto lens shot of the amazing array of nebulas in central Cygnus, around the bright star Deneb.

At left is the North America and Pelican Nebulas. At right is the Gamma Cygni complex and the little Crescent Nebula at lower right.

Here we’re looking down our local Cygnus-Orion arm of the Milky Way into a region of star formation rich in glowing hydrogen gas and dark interstellar dust. These clouds lie about 1500 to 3000 light years away. Dotting the field are hot blue stars newly formed from the raw ingredients making stars in Cygnus.

At top, the clouds have a lacework appearance, like sections of bubbles. Perhaps these are being blown across space by the high-velocity winds streaming from the young stars.

– Alan, September 13, 2013 / © 2013 Alan Dyer

 

Log Cabin in the Milky Way


Milky Way over Log Cabin (July 11, 2013)

The summer Milky Way shines over a log cabin in the woods of the Cypress Hills.

This was the view this morning, at 2 a.m., as the Milky Way of northern summer shone over my vacation log cabin on the Reesor Ranch in Saskatchewan. After the clouds cleared the sky was beautifully dark for a while before the early dawn twilight came on.

The view here takes in the Milky Way from the Scutum star cloud above the trees to the dark dust clouds of northern Cygnus overhead. The trio of Summer Triangle stars, Deneb, Vega and Altair, flank the Milky Way.

This is a composite of five tracked and stacked images for the sky and one image for the foreground shot with the iOptron Skytracker running at half speed to minimize the blurring from the tracking motion. The lens was the 14mm Samyang at f/2.8.

– Alan, July 12, 2013 / © 2013 Alan Dyer

 

A Galaxy Floating in the Void


M109 in Ursa Major (130mm 60Da)

A galaxy 80 million light years away floats in the blackness of space near a star in the Big Dipper.

This is Messier 109, a bright spiral galaxy in Ursa Major, and within an eyepiece and camera field of the bright naked eye star Gamma Ursa Majoris. That’s the “bottom left” star in the bowl of the Big Dipper, so this is an easy galaxy to find with a telescope in the current spring sky.

Technically, this galaxy is classed as a barred spiral because of the way its spiral arms emerge from an elongated bar at the core of the galaxy. It is the brightest member of the Ursa Major Cluster of some 80 galaxies.

Springtime is galaxy time, no matter what hemisphere you live in. But for us in the northern half of the planet that means April and May. When we look up at this time of year into the evening sky we are looking out of the plane of our Milky Way galaxy and seeing into the depths of intergalactic space, populated by thousands of other galaxies. Most of the bright ones, like M109, are 20 to 100 million light years away. At its distance of 80 million light years, M109 lies a million times farther away from us than Gamma Ursa Majoris, a nearby blue star “just” 80 light years away and in our Galaxy.

I shot this last weekend though my 5-inch refractor with the Canon 60Da camera. Even with the telescope’s 800mm focal length it isn’t enough to really do justice to the intricate detail in galaxies like this. But the view does set the galaxy into its context, floating in the blackness of space.

– Alan, May 11, 2013 / © 2013 Alan Dyer

Skies of Enchantment – Summer Milky Way Rising


Summer Milky Rising over Adobe House (14mm 5DII)

If you lived here you’d be in astronomy paradise.

This is the summer Milky Way and galactic centre in Sagittarius and Scorpius rising before dawn early this morning. The setting is the Painted Pony Resort in New Mexico, and its adobe lodges.

There’s no more spectacular sight than this in the night sky, other than perhaps an all-sky aurora display. And they don’t get too many of those down here at 31° North in southern New Mexico.

This image is a stack of ten 3-minute exposures for the sky (to smooth out noise) but the ground is from just 2 of those exposures and is blurred because the camera was tracking the sky. Light from walkway lights, plus starlight itself, added just enough illumination to provide details in the foreground.

So to be clear – this is a real scene. The Milky Way has not been pasted onto a separate image of the foreground. However, colour and contrast have been boosted to bring out details your eye would not have seen had you been standing here early this morning in the frosty New Mexico night.

Again, as with my previous image taken earlier in the night, I used the new Samyang 14mm ultra-wide angle lens, at f/2.8. It works very well!

– Alan, March 11, 2013 / © 2013 Alan Dyer

A Luminous Starfield


M38 & IC 405-410-417 Complex (92mm 6D)

The Starfish and the Flaming Star combine to create a rich star field in the Charioteer.

I shot this last week, using a favourite small refractor that takes in a generous field of view for a telescope. In this case, it frames the star cluster at left called the Starfish Cluster, or better known as Messier 38. At right the large number 7-shaped patch of nebulosity is the Flaming Star Nebula, known by its catalog number as IC 405. At bottom, the nameless companion nebulas are IC 417 at left and IC 410 at bottom centre.

Of note is the colourful grouping of six stars at right called the Little Fish. It’s not a proper star cluster but an asterism, a chance alignment of stars that happens to look like something imaginative. David Ratledge presents a nice list and photo gallery of similar whimsical asterisms at his Deep-Sky.co.uk website.

The entire field is a rich hunting ground for the eyepiece or camera. You can find it these nights, in winter from the northern hemisphere, straight overhead in the evening, in the middle of Auriga the Charioteer.

For this portrait I shot and stacked eight 7-minute exposures at ISO 800 using a filter-modified Canon 6D on my TMB 92mm apo refractor at f/4.8.

Happy Valentine’s Day!

– Alan, February 14, 2013 / © 2013 Alan Dyer

 

The Subtle Glow of Comet Dust


Zodiacal Light rfrom Home (Feb 8, 2013)

Out of the skyglow from lights and the remains of twilight rises a tapering pyramid of light. It’s one of the night sky’s most subtle sights for the naked eye.

This is the Zodiacal Light, and I’ve been trying to capture it in the evening sky from home for a number of years. Last night was a good night for it. The sky was very transparent, for the first couple of hours at least. An ultra-wide angle lens allowed me to capture the Light in context with the wider sky, towering out of the southwest at right, reaching up to the Pleiades and Jupiter high in the centre of the frame. The Milky Way is at left. Everyone knows the Milky Way but the Zodiacal Light is less famous.

It’s visible only in the hour or two after sunset or before sunrise. Late winter and spring are the best times to see it in the evening sky. That’s when the ecliptic – the plane of the solar system where the planets lie – is tipped up at its highest angle above the horizon putting it above obscuring haze. The Zodiacal Light lies along the ecliptic because it is part of our solar system, not in our atmosphere. It is sunlight reflected off dust orbiting in the inner solar system that’s been cast off over thousands of years by comets passing through. It is brightest closest to the Sun and fades out at greater angles away from the Sun. Thus its tapering appearance in my sky as the photo shows, very much as my eye saw it.

It takes a good night at a dark site to see the Zodiacal Light. But take a look at the next dark of the Moon. You’ll be surprised at how easy it is to see once you know what to look for.

– Alan, February 9, 2013 / © 2013 Alan Dyer

 

The Beautiful Belt of Orion


Belt of Orion & B33 Horsehead Nebula (92mm 6D)

Everyone knows the Belt of Orion, but only the camera reveals the wealth of colours that surround it.

I shot this Friday night, February 8, under very clear sky conditions.

While I used a telescope, it had a short enough focal length, about 480mm, that the field took in all three stars in the Belt: from left to right, Alnitak, Alnilam, and Mintaka. All are hot blue stars embedded in colourful clouds. The most famous is the Horsehead Nebula, running down from Alnitak at left. Above the star is the salmon-coloured Flame Nebula. All manner of bits of blue and cyan nebulas dot the field, their colour coming from the blue starlight the dust reflects.

Dimmer dust clouds more removed from nearby stars glow with browns and yellows. At left, a large swath of sky is obscured by gas and dust simmering in dull red. The entire field is peppered with young blue stars.

It is certainly one of the most vibrant regions of sky, though only long exposures and image processing bring out the colours.

This is another test shot with a new Canon 6D that has had its sensor filter modified to transmit more of the deep red light of these types of nebulas. The camera works very well indeed!

– Alan, February 8, 2013 / © 2013 Alan Dyer

Snapshots of Starlife


IC 443 Jellyfish Nebula & M35 (92mm 6D)

This one image frames examples of both the beginning and end points of a star’s life.

I shot this last night, February 6, 2013, capturing a field in the constellation of Gemini the twins. At upper right is the showpiece star cluster known as Messier 35. It’s a collection of fairly young stars still hanging around together after forming from a cloud of interstellar gas tens of millions of years ago. M35 lies about 2,800 light years from Earth, on the other side of the spiral arm we live in. Just below M35 you can see another smaller and denser cluster. That’s NGC 2158, about five times farther away from us, thus its smaller apparent size. Both are objects that represent the early stages of a star’s life.

At lower left is an object known as the Jellyfish Nebula, for obvious reasons. The official name is IC 443. It’s the expanding remains of a star that blew up as a supernova anywhere from 3,000 to 30,000 years ago. What’s left of the star’s core can still be detected as a spinning neutron star. You need a radio telescope to see that object, but the blasted remains of the star’s outer layers can be seen through a large backyard telescope as a shell of gas. It is expanding into the space between stars – the interstellar medium – ploughing into other gas clouds. The shockwave from its collision with other nebulas may trigger those clouds to collapse and form clusters of new stars. And so it goes in the Galaxy.

For this portrait of stellar lifestyles, I used a 92mm apochromatic refractor and a new Canon 6D camera, one that has had its sensor filter modified to accept a greater range of deep red light emitted by hydrogen nebulas. The image is actually a stack of 12 exposures with an accumulated exposure time of 80 minutes.

– Alan, February 7, 2013 / © 2013 Alan Dyer

An Orion Portrait from Alberta


Orion in Porttrait Format

He’s certainly the sky’s most photogenic mythological figure. Here’s my full-length portrait of Orion the hunter, captured from Alberta.

I’ve shot him many times before but this was a new combination of gear: the Canon 60Da camera and the Sigma 50mm lens, nicely framing the hunter in portrait format. This version of Orion isn’t as deep as the one I took last month from Australia. But skies were darker there, and I used my filter-modified Canon 5D MkII for his Oz portrait, a camera which picks up more faint red nebulosity than does the 60Da, Canon’s own specialized DSLR camera for astronomy. The 60Da does do a very good job though, much better than would a normal DSLR.

For this shot, as I do for many constellation images, I layered in exposures taken through a soft-focus filter, the Kenko Softon, to enlarge and “fuzzify” the stars! It really helps bring out their colours, contrasting cool, orange Betelgeuse with the hot blue-white stars in the rest of Orion.

I shot this January 4 on a fine clear winter night, the classic hunting ground for Orion.

– Alan, January 11, 2013 / © 2013 Alan Dyer

Jupiter Amid the Clusters of Taurus


Jupiter in Taurus (January 4, 2013)

Look up on a clear night this season (winter for us in the northern hemisphere) and you’ll see a bright object shining in Taurus the bull. That’s Jupiter.

This year Jupiter sits in a photogenic region of the sky, directly above the stars of the Hyades star cluster and yellow Aldebaran, the brightest star in Taurus. Above and to the west (right) of Jupiter is the blue Pleiades star cluster.

Over the course of January 2013 you’ll be able to see Jupiter move a little further west each night (to the right in this photo) away from Aldebaran and toward the Pleiades. Jupiter will stop its retrograde motion on January 30. After that it treks eastward to again pass above the Hyades and Aldebaran (returning to where it is now) in early March.

Jupiter’s proximity to Aldebaran and the Hyades makes it easy to follow its retrograde loop over the next few weeks. It’s an easy phenomenon to watch, but explaining it took society hundreds of years and the ultimate in paradigm shifts in thinking, from the self-important arrogance that Earth – and we – were the centre of the universe, to the Sun-centered view of space, with Earth demoted to being just one planet orbiting our star.

I took this image Friday night, January 4, from home as my first astrophoto upon returning to Canada from Australia. It’s a combination of two sets of images: one taken “straight & unfiltered” and one taken through a soft-focus filter to add the glows around the stars and central, brilliant Jupiter. I then blended the filtered images onto the normal images in Photoshop with the Lighten blend mode.

– Alan, January 5, 2013 / © 2013 Alan Dyer

A Truly Amazing Sky — A New Year’s Gift


Timor Cottage Panorama #3

As we end 2012 and start a new year, I wish everyone a very happy 2013 and leave you with this view of a very amazing sky.

This is a 360° panorama of the Milky Way over Timor Cottage on a very clear night in mid-December in New South Wales, Australia. May all your skies be as wonderful and as inspiring as this in the coming year.

Indeed, we have some potentially remarkable sights to look forward to, with the prospects of two bright comets in 2013: Comet PANSTARRS in March and Comet ISON in November and December.

Let’s hope for more amazing skies in 2013. Keep looking up!

– Alan, December 31, 2012 / © 2012 Alan Dyer

Zooming into Canis Major – #3


NGC 2359 Thor's Helmet NebulaIn the third instalment in my trilogy of Canis Major zooms, I present this close-up of another neat nebula in the Great Hunting Dog, called Thor’s Helmet.

You can tell just by the colour that this is a different type of nebula than the typical red hydrogen gas clouds, such as the Seagull Nebula of my previous post. Yes, this is glowing gas but this nebula originates from a different source than most. Rather than being a site where stars form this is a nebula surrounding an aging star, a massive superhot star that is shedding shells of gas in an effort to lose weight – or mass as we should say.

Intense winds from the star blow the gas into bubbles, and cause it to fluoresce in shades of cyan. The central star is one of a rare stellar type called a Wolf-Rayet star, named for the pair of French astronomers who discovered this class of star in the 19th century. WR stars are likely candidates to explode as supernovas.

This particular Wolf-Rayet nebula, catalogued as NGC 2359, has a complex set of intersecting bubbles that, through the eyepiece, do take on the appearance of a Viking helmet with protruding horns, like you see in the Bugs Bunny cartoon operas! It’s a neat object to look at with as big a telescope as you can muster. And, as you can see, it’s rather photogenic as well, embedded in a rich field with faint star cluster companions.

– Alan, December 28, 2012 / © 2012 Alan Dyer

Zooming into Canis Major – #2


IC 2177 Seagull Nebula Complex

Zooming in closer yet again to the field in Canis Major I showed in my previous post, I’m now framing the large nebula known as the Seagull. Perhaps you can see him flying through the stars.

The catalog number for this object is IC 2177, but the bright round nebula at right (the head of the Seagull?) is object #1 in the catalog of Australian astronomer Colin Gum. It’s also object #2327 in the familiar NGC listing that all stargazers use.

Some of this nebulosity is just visible through a small telescope, especially with the aid of a nebula filter than accentuates the emission lines – the colours – emitted by these kinds of glowing gas clouds.

This is certainly a photogenic field, with a nice mix of pinks, blues, purples and deep reds.

I used my 4-inch (105mm aperture) f/5.8 apo refractor to shoot this target, so the field is fairly narrow, framing what a telescope would show at very low power.

(FYI – The image info listed at left, automatically picked off the image’s EXIF data by the WordPress blog software, fails to record the focal length of the optics properly, as I didn’t use a standard camera lens but a telescope the camera doesn’t know about.)

I’ve been after a good shot of this object for some years, but haven’t been successful until this past observing run in Australia, in December 2012. While I can see and shoot the Seagull Nebula from home in Alberta, it’s always very low in my home sky. From Australia the challenge was framing the field with the Seagull overhead at the zenith. Just looking through the camera aimed straight up took some ground grovelling effort. Plus avoiding having the telescope hit the tripod as it tracked the object over the hour or so worth of exposures – typically 4 to 5 that I then stack to reduce noise.

– Alan, December 28, 2012 / © 2012 Alan Dyer

 

Zooming into Canis Major – #1


M50 - M46/M47 Area Bino Field

My last post featured a wide view of Canis Major. Here, we zoom in closer to one of the most interesting regions in that constellation, filled with nebulas and clusters.

The prominent red arc is the Seagull Nebula, aka IC 2177. Above and to the right of the Seagull is a clump of stars called Messier 50, which lies over the border in the constellation of Monoceros the Unicorn.

At the lower left edge of the frame sits a pair of dissimilar star clusters, Messier 46 (the left one) and Messier 47 (the right one). M46 is a dense rich cluster of stars while M47 is brighter but looser and more scattered.

Several other non-Messier clusters punctuate the field. This is a great area of sky to explore with binoculars.

Just below centre you might see a small green-blue patch. That’s the nebula called Thor’s Helmet, or NGC 2359, a fine telescopic object.

If you get a clear night this season when the Moon is out of the way and you can head to a dark sky, Canis Major, the Hunting Dog, is a great hunting ground for deep-sky fans.

As the data at left shows, I shot this with a 135mm telephoto lens, giving a field of view similar to what binoculars would show.

– Alan, December 28, 2012 / © 2012 Alan Dyer

Canis Major and the Dog Star


Canis Major from Australia (50mm 5DII)

Shining in the southern sky these nights are the stars of Canis Major, the big hunting dog of Orion the Hunter. Among them is the famous Dog Star, Sirius, the brightest star in the night sky.

Can you see a dog outlined in stars? Sirius marks his head – or it is sometimes depicted as a jewel in his collar. His hind legs and tail are at the bottom of the frame.

I shot this earlier this month from Australia, where Sirius and Canis Major stand high overhead. From northern latitudes you can see these stars due south low in the sky about midnight. Sirius is hard to miss, often sparkling through many colours as our atmosphere distorts its light. But as the photo shows, it is really a hot blue-white star. While it is intrinsically a bright star, much of its brilliance in our sky comes from its proximity, only 9 light years away from us.

For this portrait of the celestial canine I used a 50mm “normal” lens. The atmosphere provided some natural haze this night, to add the glows around the stars accentuating their colours.

This area of sky also contains several nebulas, notably the red arc of the Seagull Nebula to the left of Sirius. Below Sirius you can also see the star cluster Messier 41, a good target for binoculars.

Toward the left edge of the frame you can see a pair of star clusters, Messier 46 and Messier 47, two other excellent binocular objects in the Milky Way, which runs down the frame to the left of Canis Major. The dog is just climbing out of the Milky Way after a swim in this river of stars.

– Alan, December 28, 2012 / © 2012 Alan Dyer

 

The Christmas Tree Cluster


NGC 2264 Christmas Tree Cluster & Cone Nebula

 

The current night sky contains another seasonal sight, a cluster of stars called the Christmas Tree Cluster. Turn the image upside down and you might see it!

The bright star lies at the base of the Christmas tree and at the bottom of a tall triangle of blue and yellow stars that outlines – or decorates – the tree. At the top of the tree sits the dark Cone Nebula. The Tree also encompasses a bright blue dusty nebula reflecting the light of nearby stars and swirls of pink glowing hydrogen. At right sits a rich cluster of stars dimmed yellow by intervening dust. At bottom (south) in this photo you can also see a small V-shaped object. That’s Hubble’s Variable Nebula, a dust cloud studied by Edwin Hubble, one that varies in intensity with fluctuations in the main star embedded at its tip.

This rich area of sky lies above (north of) the subject of my previous post, the Rosette Nebula in the constellation of Monoceros the Unicorn. Very little of this is visible to the eye. The magic of photography is how it coaxes detail out of the sky that the eye alone cannot see.

– Alan, December 27, 2012 / © 2012 Alan Dyer

 

A Cosmic Wreath in the Sky


NGC 2237 Rosette Nebula

This is the Rosette Nebula, a celestial wreath 5,000 light years in the northern winter sky.

It is one of the most photogenic of nebulas, but is barely visible to even an aided eye as a ghostly grey arc of light around the central star cluster. Winds from the group of hot stars at the centre of the Rosette are blowing a hole in the cloud, creating the wreath-like shape of the Rosette.

While I shot this earlier this month from Australia, the Rosette lies far enough north in the constellation of Monoceros that northerners can see this cosmic wreath on any dark and clear winter night. It makes a beautiful decoration in our holiday sky.

Happy holidays to all!

– Alan, December 26, 2012 / © 2012 Alan Dyer

The Amazing Orion Nebula


Orion Nebula Complex, M42, M43, NGC 1973-5-7

My Australian nights are proving to be frequently and thankfully clear enough that I’ve got the luxury of shooting some familiar “home sky” objects. This is the famous Orion Nebula in the Sword of Orion, about 1500 light years away.

I’ve shot this nebula many times from the northern hemisphere but my Australian skies are darker than at home, and the nights a lot warmer than when this object is up in our winter sky.

The Orion Nebula is a complex consisting of Messier 42, the main nebula, M43, a small nebula attached to the north (above) and the bluish Running Man Nebula (can you see his dark figure?) at top that is officially catalogued as NGC 1973-5-7. Together, these make up the largest region of star formation in our corner of the Milky Way. It’s easy to see with the unaided eye on a dark night.

To shoot this, I blended three different exposures, short (4 x 1 minute), medium (4 x 5 minutes) and long (4 x 15 minutes), to preserve all the details from the intensely bright core our to the faint tendrils extending into deep space. I stacked the 4 frames taken at each of the exposure times, then blended those stacks using masks in Photoshop CS6 (and its wonderful and editable Refine Mask function) to mask out the overexposed area of the longer exposure and let the shorter exposure content shine through. The result is that the core still shows the little cluster of stars, the Trapezium, and the characteristic green tint of the core. But I applied lots of Curves to bring out the fainter bits and swirls in the periphery.

I shot this through my Astro-Physics Traveler 105mm refractor at f/5.8 using the filter-modified Canon 5D MkII camera, at ISO 400. This turned out to be certainly my best shot of Orion yet in my library.

– Alan, December 13, 2012 / © 2012 Alan Dyer

Southern Milky Way in the Blue of Dawn


Southern Milky Way at Dawn (December 2012)

At the end of a nearly perfect night of southern stargazing, I shot this wide-angle portrait of the southern Milky Way embedded in the deep blue of morning twilight.

In December at dawn, the southern Milky Way extends from Orion (at the extreme right) down through Canis Major, Puppis and Vela (where you can see a large faint red bubble-shaped nebula high in the south) then continues east (left) into Carina and Crux. The red Carina Nebula sits in the Milky Way and the Southern Cross is at left, rising before the two Pointer Stars, Alpha and Beta Centauri. The Magellanic Clouds sits above the cottage I’m using as my southern hemisphere home for stargazing while I am in Australia.

– Alan, December 12, 2012 / © 2012 Alan Dyer

 

Southern Spectacular in Carina


Carina Nebula

The Carina Nebula ranks as one of the most spectacular sights in the southern sky.

I shot this last night under perfect conditions. I’ve shot this nebula many times before but had to have a go at it again – I think this version is the best yet of many I’ve taken over the years of coming to the southern hemisphere to shoot the sky. I shot this through my 4-inch apo refractor with a filter-modified Canon 5D MkII camera. It’s a stack of five 12-minute exposures at ISO 400.

This massive nebula is the site of loads of star formation, and home to one massive young star, Eta Carinae, that is a prime candidate for a supernova explosion sometime soon. That will certainly stir things up in Carina. This object sits over 6,000 light years away in the next spiral arm in from ours, the Carina-Sagittarius Arm of the Milky Way.

Through the telescope it fills the field with intricate shades of grey — the colours show up only in photos – with one bright yellow star at the centre, Eta Carinae itself shrouded in the golden-hued nebula it cast off during its last explosive outburst in the 1840s.

Like the Large Magellanic Cloud, this is one object worth the trip to southern skies just to see for yourself.

– Alan, December 12, 2012 / © 2012 Alan Dyer

In the Lair of the Tarantula Nebula


NGC 2070 Tarantula Nebula area of LMC (105mm 5DII)

This is one of the most spectacular areas of the southern sky, around the lair of the Tarantula Nebula.

I shot this close up of the Large Magellanic Cloud last night, December 10, 2012 to frame the most interesting part of the LMC, the massive Tarantula Nebula. This star-forming region is much larger than any in our Milky Way, yet exists in a small dwarf galaxy that is a satellite of our Milky Way. But tidal forces from our Milky Way are torturing the Magellanic Clouds and stirring up massive amounts of star formation. If the Tarantula were as close to us as is the Orion Nebula some 1500 light years from us, the Tarantula would cover 30° of sky and cast shadows at night. Good thing perhaps that the wicked Tarantula is 160,000 light years away.

I shot this with my 105mm apo refractor. It’s a stack of 5 x 12 minute guided exposures, using the filter-modified Canon 5D MkII camera.

This is a wonderful region of sky to explore with any telescope. I had a great look at it through my 10-inch Dobsonian reflector last night. Well worth the trip to the southern hemisphere to see!

– Alan, December 11, 2012 / © 2012 Alan Dyer

 

Depth of Detail in the Large Magellanic Cloud


Large Magellanic Cloud (135mm)

If this was the only unique object in the southern sky that we couldn’t see from up North, then it would still be worth travelling south of the equator to see the southern sky.

This is the Large Magellanic Cloud, a satellite galaxy to our Milky Way. Being “just” 160,000 light years away (as opposed to millions of light years for most galaxies) this object is large (it fills the field of binoculars) and is rich in detail. Just look at all the pinkish nebulas dotting its ragged structure. The biggest is near the bottom, the massive Tarantula Nebula. Through a telescope there is so much to see in this object it takes careful comparisons with charts and atlases over several nights just to figure out what all the nebulas and clusters are in the eyepiece. It is a deep-sky observer’s dream object. While several professional astronomers have made their careers studying just the Magellanic Clouds.

Once classed as an irregular, ragged galaxy, the “LMC” is now thought of as a barred spiral. I think this photo suggests the two spiral arms coming off the top and bottom of the central elongated bar.

I shot this last night, under a perfect night of viewing in Coonabarabran, Australia, using a 135mm telephoto lens. The field is similar to what you see in binoculars though the long exposure (this is a stack of ten 5-minute tracked exposures) brings out more detail than the eye can see. Compare this wide view with a higher magnification shot I took two years ago from the same location. Both are good but I like this wider view better as it sets this big object into the celestial frame of the surrounding night sky.

– Alan, December 6, 2012 / © 2012 Alan Dyer

Regal Colours of Cassiopeia


 

Sitting on the border of Queen Cassiopeia and King Cepheus is this royal cloak of pinks and reds.

Too faint to see even in a small telescope, the main cloud of nebulosity is called NGC 7822, with a companion cloud below known as Cederblad 214. Rather cold names for a stunning region of space.

I love the colours in this field. The camera I use is modified to bring out the reds of glowing hydrogen but also nicely picks up blues and purples, which mix to provide subtle shades of pink and magenta. There are even yellows and greens from dust clouds.

Yes, I’ve certainly punched up the colour and contrast quite a bit from what came out of the camera, but I tried to retain a “natural” colour balance, not skewing the palette too far to the deeply saturated monotone red I see in some images of nebulas.

I shot this Saturday night, October 6, from my backyard on a fine autumn night for stargazing and star shooting. It’s a stack of eight 12-minute exposures, “median” combined to eliminate the satellite trails that crossed several frames.

– Alan, October 6, 2012 / © 2012 Alan Dyer

City of Stars


Some 3 billion years from now we are going to collide with this galaxy.

This is the famous Andromeda Galaxy, now 2.5 million light years from us but getting closer by the day! Andromeda, a.k.a. Messier 31, is the most distant object readily visible to the naked eye. It now shines high overhead for us in the northern hemisphere.

I asked Siri, my iPad assistant, how many stars are in the Andromeda Galaxy, and she said one trillion. She’s right. Recent estimates put Andromeda’s stellar population at 3 or 4 times that of our own Milky Way Galaxy. It’s also bigger. Measuring from the outermost extremities of the disk gives a diameter of over 200,000 light years, twice the size of our home galaxy.

I took this shot last week. It’s stack of five 15-minute exposures with a new Lunt 80mm refractor. The long exposures bring out the faint halo of stars extending beyond the main bright disk, the part you see in a telescope. You can also see Andromeda’s two close companion galaxies: M32, looking like a fuzzy star below the core; and M110, the elliptical galaxy above the core and connected to the main galaxy by a bridge of faint stars.

– Alan, September 27, 2012 / © 2012 Alan Dyer

Star Death Site


This is the graveyard of where a star died at the dawn of civilization.

The Veil Nebula, made of several fragments, is the remains of a star that exploded as a supernova some 5000 to 8000 years ago. With a telescope you can see this deep sky wonder high overhead these nights, in Cygnus the swan. A decent sized telescope, say 15 to 25cm diameter, can show a lot of the detail recorded here, but only in black-and-white. It takes a photo to pick up the magentas, from glowing hydrogen, and cyans, from oxygen being excited into shining by the shockwave created as the expanding cloud ploughs into the surrounding interstellar gas.

The whole complex is called the Veil Nebula but the segment at right passing through the star 52 Cygni is called the Witch’s Broom Nebula.

I shot this from home a couple of nights ago during a continuing run of typically fine fall weather, which usually brings the best nights of the year for astronomy. For this shot I used a new Lunt 80mm apochromatic refractor on loan for testing. It works very well! This is a stack of five 15-minute exposures.

– Alan, September 22, 2012 / © 2012 Alan Dyer

Goodness Gracious! A Great Ball of Stars!


This is what half a million stars look like when packed into one big ball. 

This is the globular star cluster called Messier 22, in Sagittarius. It’s the biggest and best such object visible from Canadian latitudes, though it always sits low in our summer sky. M22 is one of 150 or so such spherical clusters of stars that orbit our Milky Way. This one sits 10,000 light years away from us, toward the centre of the Galaxy. Those half million stars are packed into a sphere 100 light years across. In our sky it appears as big as the Full Moon, though not as bright of course. But just imagine the sky if you can view it from the centre of M22. The heavens would be ablaze with stars. 

I shot this with the 130mm refractor at f/6. It’s a stack of just three 4-minute exposures with the Canon 7D. Though M22 was low above the southern horizon from the Cypress Hills where I shot this, the final image turned out pretty well. 

– Alan, August 30, 2012 / © 2012 Alan Dyer

 

The Subtle Shades of Cepheus


The Milky Way in Cepheus presents a palette of colours revealed in long exposures.

This binocular-sized field contains the large magenta nebula IC 1396, a site of star formation. On its northern (upper) edge shines the orange star Mu Cephei, otherwise known as Herschel’s Garnet Star, for its very red appearance in the eyepiece. It is a bloated red supergiant, one of the largest stars known. A few other stars in the field are younger blue giants. Faint wisps of red hydrogen fill the field (the faint crescent at right is Sharpless 129, left of centre is Sharpless 132, at top left is NGC 7380). Diagonally along the Milky Way lie dark, yellow-tinted dust clouds. The darkest patch at centre is the Barnard 169/170/171 complex. These contrast with the dust-free blue starfields of the Milky Way at left.

This is a stack of five 5-minute exposures with the 135mm telephoto and Canon 5D MkII camera, which has been filter modified to record the faint red nebulas better than a stock camera.

– Alan, August 25, 2012 / © 2012 Alan Dyer

 

Star Gazing


Happiness is a big telescope under a dark sky.

This is Regina astronomer Vance Petriew, gazing skyward at the Milky Way in Cassiopeia. Vance is the discoverer of Comet 185/P, aka Comet Petriew. This year, his comet returned to the August sky as a faint glow in Gemini, close to where it was when Vance found it exactly 11 years to the day before this image was taken, and at the very same spot in the campsite at Cypress Hills Interprovincial Park in Saskatchewan.

We all revelled in the Saskatchewan comet’s return, staying up till 4 am to see it through Vance’s 20-inch telescope, a reflector made by the small company called Obsession. (When you have an Obsession, you are a serious observer!) Enjoying the view early that morning before dawn were  Vance’s three daughters, only one of whom was around 11 years ago and then as a baby. But this year even the four-year-old was able to see Dad’s comet up close.

At the afternoon talks Vance recounted the story of how the comet’s discovery changed his life, and led to immense changes at the Park. As a result of the media and political attention the comet brought, the Park has become a Dark Sky Preserve, one of the first in Canada, leading a nationwide movement, while astronomy programming is now an integral part of the Park’s interpretive programs, as it is becoming at other provincial and national parks. There is now a permanent public observatory and lecture hall nearby in Cypress Hills, just a short walk away from where the comet was found.

Comets can have quite an impact!

— Alan, August 24, 2012 / © 2012 Alan Dyer

A Cloud of Stars in Scutum


This is a binocular-sized gulp of sky in the northern summer Milky Way. Countless stars form a bright patch in the Milky Way called the Scutum Starcloud, named for the odd little constellation of Scutum the Shield that contains it.

Visible to the naked eye, this star cloud is a rich area for binoculars or a small telescope. One favourite object of stargazers lies embedded in the star cloud and can be seen here as a bright clump of stars at left of centre. That’s the Wild Duck Cluster, or Messier 11, a dense and populous cluster of stars within the already star-packed Scutum Starcloud. Look in this direction into the Milky Way and you are looking toward the next spiral arm in from ours, some 6,000 light years away.

The immensity of stars in just this small area of sky is hard to fathom. That’s why it’s called deep space!

– Alan, August 9, 2012 / © 2012 Alan Dyer

 

A River of Starlight and Dust


 

Look up on a dark summer night in the northern hemisphere and you see a river of stars flowing across the sky.

This is the Milky Way, a glowing mass of millions of distant stars populating the spiral arms of the Galaxy we live in. Lining the arms are lanes of dark interstellar dust, seen here splitting the Milky Way in two from the bright red North America Nebula at top, down to the core of the Galaxy in Sagittarius on the horizon. The dust is the soot created in stars and blown into space to form a new generation stars and planets.

This ultra-wide-angle scene takes in almost the entire summer Milky Way from the southern horizon to beyond the zenith overhead at top. I shot this a couple of nights ago from my rural backyard on a particularly transparent and dark night. It was heaven on Earth.

— Alan, July 26, 2012 / © @ 2012 Alan Dyer

 

Chariot of the Sky


Auriga the Charioteer rides high across the northern winter sky these nights. This is a wide-field image I took last week of the constellation that now shines overhead from northern latitudes.

My image takes in all of Auriga, the pentagon-shaped charioteer of Roman mythology, as well as the feet of Gemini the twins, spanning a wide area of the winter Milky Way. Sprinkled along this bit of Milky Way you can see a few clusters of stars. They include four of the best open star clusters in the catalogue of Charles Messier: M35 in Gemini at bottom, and M36, M37 and M38 in Auriga at centre, all wonderful targets for a small telescope. Some of these targets lie in the next spiral arm out from the one we live in.

The star colours show up nicely here, with the brightest star at top appearing a little off white. That’s Capella, 42 light years away and classified as a type G “yellow” star not unlike our own Sun in temperature but much larger – a giant star. Indeed, it is really two yellow-giant stars in close orbit around each other. It’s interesting that Capella doesn’t really show up as yellow. Just like our Sun does to our eyes, Capella appears white because it still emits such a broad range of colours that even though its peak energy does fall in the yellow part of the spectrum, all the other colours remain strong enough that the star looks white to our eyes. Remember, our eyes evolved under the light of a type G star to see all the colours of the spectrum from red to blue.

Only the cool red giant stars take on a yellow or orange hue to our eyes, and to the camera. You can see a few in this image, as well as hot blue stars. The pinky red bits are nebulas in the Milky Way – clouds of hydrogen gas emitting deep red light.

When we look in this direction in the Milky Way we are looking out toward the edge of our Galaxy, exactly opposite the galactic centre.

– Alan, February 21, 2012 / © 2012 Alan Dyer

The Rose of Winter


While I took this shot three weeks ago, I’ve only just got around to processing it. This is a nebula-filled region of the northern winter sky in the constellation of Monoceros, the unicorn.

The highlight is the rose-like Rosette Nebula at bottom, an interstellar flower of glowing hydrogen where new stars are forming. Above it, at centre, is a mass of pink, blue and deep red nebulosity that forms the Monoceros Complex. All lie in our local corner of the Milky Way, in a spiral arm fragment called the Orion Spur, a hotbed of star formation.

This field, shot with a 135mm telephoto lens, sits to the left of Orion and spans about a hand width at arm’s length. It would take a couple of binocular fields to contain it. Next on my astrophoto agenda – shooting some close ups of selected bits of Monoceros, shots that have eluded me till now.

— Alan, February 12, 2012 / © 2012 Alan Dyer

Celestial Pinks and Blues


 

Who says the dark night sky isn’t colourful? Of course, to the naked eye it mostly is, with the darkness punctuated only with a few red, yellow and blues stars. But expose a camera for long enough and all kinds of colour begins to appear.

This region is above us now, in the Northern Hemisphere evening sky for mid-winter. It’s the boundary area between Taurus and Perseus. Below are the vivid blues of the hot young Pleiades star cluster in Taurus. At top, just squeezing into the frame, is the shocking pink of the California Nebula, a glowing cloud of hydrogen gas in Perseus.

But between are the subtle hues of faint nebulosity weaving all through the Perseus-Taurus border zone. Below are faint cyans and blues from dust clouds reflecting the light of the Pleiades stars. In the middle are the yellow-browns of dark dust clouds hardly emitting light at all, but snaking across the frame to end in a complex of pink and blue straddling the border collectively known as IC 348 and IC 1333. At top, the glowing hydrogen gas of the California emits a mix of red and blue wavelengths, creating the hot pink tones, but fading to a deeper red to the left as the nebula thins out to the east. Throughout, hot blue stars pepper the sky and help illuminate the dust and gas clouds which will likely form more hot stars in the eons to come.

I took this shot last Wednesday night, on one of the few clear, haze-free nights of late. This is a “piggybacked shot,” with the Canon 5D MkII camera going along for the ride on one of my tracking mounts. This final shot is a stack of five 6-minute exposures, highly processed to bring out the faint clouds barely brighter than the sky itself. The camera was equipped with a 135mm telephoto lens, giving a field of view a couple of binocular fields wide. Hold out your hand and your outstretched palm would nicely cover  this area of sky. But only the camera reveals what is actually there.

— Alan, January 29, 2012 / Image © 2012 Alan Dyer

Set the Controls for Triangulum


 

Spiral galaxies are icons of deep space. This one is a classic. This is the Triangulum Galaxy, named for its home constellation. Amateur astronomers also know it as M33, the 33rd entry in Charles Messier’s catalog of deep sky objects compiled in the 1780s. To Messier, object #33 was another fuzzy spot he and others might confuse for comets, the objects astronomers of the day were really after.

It wasn’t until 1850 that the Earl of Rosse, observing with his monster Leviathan of Parsonstown, a 72-inch reflector telescope, managed to see M33 as something more than a nebulous glow. He saw what the photo clearly shows — spiral arms swirling around a central core. However, in those days, such “spiral nebulae” were thought to be whirlpools of gas where stars and solar systems were forming.

It wasn’t until the 1920s, with the work of Edwin Hubble, that objects like M33 were proven to be other galaxies like our Milky Way, each composed of billions of stars.

We now know the Triangulum Galaxy lies about 3 million light years away, and is about half the size of our Milky Way. That makes it the third largest member of our Local Group of galaxies, after our own Milky Way and the famous Andromeda Galaxy.

For this shot of M33, taken September 25, I stacked 6 images, each a 12-minute exposure at ISO 800 and f/6, shot with my Astro-Physics 130mm refractor and Canon 7D camera. Visible along the galaxy’s spiral arms you can see some of the reddish and cyan-coloured nebulas that are sites of active star formation in M33.

— Alan, Oct 7, 2011 / Image © 2011 Alan Dyer

The Stellar Triangle of Summer




When the Summer Triangle sinks into the west, we know summer has come to an end. While the stars of the Summer Triangle are now high overhead from northern latitudes as the sky gets dark, by late evening the Summer Triangle is setting into the west.

These three bright stars are an example of stellar variety:

– At bottom is Altair in Aquila the eagle. It’s a white main-sequence star 17 light years away, fairly nearby by stellar standards. Leslie Nielson and his crew went to Altair in the 1950s movie Forbidden Planet.

– At top right is Vega, in Lyra the harp, a hotter and more luminous blue-white star than Altair, making it appear brighter than Altair, despite Vega being farther away, at 25 light years distant. Jodi Foster went to Vega in the movie Contact.

– But the third member of the Triangle, Deneb, at top left, is an extreme star. It appears a little fainter than Vega, but looks can be deceiving. Deneb is actually a luminous supergiant star, putting out 54,000 times the energy of our Sun. Deneb is about 1,400 light years away and yet, due to its fierce output of light, appears almost as bright as Vega. Light from Deneb left that star in the 6th century. I don’t know of any movie heroes who went to Deneb. The name means “tail of the Swan,” hardly a romantic destination for space-faring adventurers.

Look toward the Summer Triangle and you are looking down the spiral arm of the Milky Way that we live in. The stars of that arm appear as a packed stellar cloud running through Cygnus the swan, the constellation that contains Deneb.

I took this shot Saturday night, from home, on what turned out to be a very clear night, once some clouds got out of the way in the early evening. This is a 4-image stack of 8-minute exposures, at f/4 with the 35mm Canon lens, a favourite of mine, on the Canon 5D MkII at ISO 800. I added in exposures taken through a soft-focus filter to give the added glows around the stars to help make the bright stars and their colours more visible.

— Alan, September 25, 2011 / Image © 2011 Alan Dyer

The Comet and the Cluster


This was the scene Monday night and into Tuesday morning, August 1/2, as a relatively new comet to our skies passed a bright globular cluster known as M15 in Pegasus. The comet is Comet Garradd, or more formally C/2009 P1. Here it glows with the characteristic cyan tint of many comets and sports a stubby fan-shaped tail.

As comets move across the sky they often appear near prominent deep-sky objects for a night or two before moving on. Comet Garradd has a number of such encounters coming up: with the globular cluster M71 on August 26, and then near the neat Coathanger cluster September 1 through 3.

Comet Garradd can be spotted now from a dark site in big astronomy binoculars and is a fine sight in a telescope. However, it is well below the threshold of naked-eye brightness and is expected to remain so as it moves high across the summer sky from east to west and then into the western evening sky in late autumn. It is certainly well-placed for viewing, but only comet aficionados are likely to pay much attention to it. Plus astrophotographers taking advantage of photo ops like this one.

— Alan, August 2, 2011 / Image © 2011 Alan Dyer


The Glowing Heart of Cygnus


Look straight up on a summer night in the northern hemisphere and you are looking into this region of sky. This is the centre — the heart — of Cygnus the swan, marked here by the bright star called Sadr, or Gamma Cygni.

While the star is easily visible to the unaided eye, the glowing clouds of gas surrounding it are not. Only long exposure images reveal the amazing swirls of nebulosity in the middle of Cygnus.

The main cloud at left, split by a dark lane of dust, is catalogued as IC 1318. The little crescent-shaped nebula at right is NGC 6888, or more appropriately, the Crescent Nebula. It formed when a hot giant star blew off its outer layers, to add to the general melee of hydrogen and other elements. But note the little blue reflection nebulas at top left. Oddly out of place!

New stars are forming in this region, located about 1500 light years away down the Cygnus arm that we live in, in the Milky Way Galaxy.

This field can be framed nicely by binoculars or a low-power telescope, but only the brightest bits of this nebulosity will show up in the eyepiece as grey ghosts, and then only with the aid of a specialized nebula filter.

I took this shot on Saturday night, July 30, 2011 with the Borg 77mm f/4 astrograph lens and Canon 5D MkII camera. Other stats are similar to the previous blog post. It’s certainly my best shot of this area of sky.

— Alan, August 1, 2011 / Image © 2011 Alan Dyer

 

The Eagle and the Swan


Though they are truly “nebulous,” these clouds of interstellar gas carry fanciful names — our human attempt to make sense of the vast chaotic forms that pervade deep space.

Above is the Eagle Nebula, a.k.a. Messier 16. Below lies the Swan Nebula, a.k.a. Messier 17. Through a telescope to the eye these nebulas do take on the imagined shape of interstellar birds flying along the Milky Way. But long exposure images like this bring out far more than the eye can see. The entire field, here about the width of what high-power binoculars take in, is filled with swirls of hydrogen gas, glowing in its characteristic red colour.

The Eagle Nebula lies in the constellation of Serpens the serpent, while the Swan Nebula lies just over the border in Sagittarius the archer.

I took this shot Saturday night, July 30, 2011, on one the few perfect nights of observing we get here in Canada — the night was warm, dry, with little wind and no mosquitoes. I could venture out with just a sweater on for a bit of warmth. A far cry from the parkas and down-filled boots normally needed.

This field is a first for me from Canada. I’ve shot it from Australia and Chile, where these objects lie overhead, never from home in Alberta at a latitude of 51° North. But the night was so transparent, the field was worth going after, despite it being low on the southern horizon and at its best for no more than an hour after it got dark.

To shoot the field, I used the wonderful little Borg 77mm f/4 astrographic refractor, effectively a 300mm telephoto lens but far sharper and flatter than most telephotos made for sports and wildlife. The camera was the Canon 5D MkII, a filter-modified version that has a special filter for passing more of the deep red colour of hydrogen. But the real difference here was the use of a filter at the focus of the telescope that further isolated the red wavelengths and blocked other colours that might have otherwise fogged the image, especially from a field so low on the horizon. It worked great, though does tend to render the whole field on the red side.

— Alan, July 31, 2011 / Image © 2011 Alan Dyer

 

A Window in the Stars


In this part of the sky the Milky Way takes on a surprising palette of hues. And it’s all due to dust.

The centrepiece of this shot is a bright star cloud in Sagittarius called, well, the Sagittarius Star Cloud! But not the Large one. This is the Small Sagittarius Star Cloud, a.k.a. Messier 24, a mass of stars with a single black eye. The dark spot, called Barnard 92, is a dense and opaque cloud of dust. Stardust — clouds of carbon soot blown out by aging stars — weaves all through this scene, creating the dark canyons winding through the stars. Obscuring dust also dims much of the background stars and discolours most of this part of the Milky Way a yellowish brown. It’s the same effect that dims the setting Sun a deep orange or red, as its light shines through haze and dust in the sky.

But here, the Star Cloud looks bluish and “cleaner.” That part of the Milky Way has less dust in front of it. And yet it is much farther away than the yellow dusty starfields around it. When we look toward the Small Sagittarius Star Cloud we are looking through a dust-free window, allowing us to see unencumbered right past our Galaxy’s nearby Sagittarius-Carina spiral arm to glimpse a dense part of the more distant Norma Arm, an inner spiral arm of our Milky Way Galaxy about 12,000 to 16,000 light years away.

To the lower right of M24 is M23, a rich cluster of stars 2,000 light years away, nearby by galactic standards, and so sits suspended in front of the fainter star background. The pinkish nebula at top is Messier 17, the Swan Nebula.

I took this shot May 2 from Chile, using the Canon 7D and 135 lens, for a stack of six 2-minute exposures.

— Alan, June 7, 2011 / Image © 2011 Alan Dyer

 

 

Rose of the Southern Sky


It’s been a month since my last post, a month with no new astrophotos from home. But I’ve got a backlog of RAW files to work through from the Chile trip a month ago. Here’s a new image from that shooting expedition. It’s of an area of the southern sky that lends itself to every focal length and framing variation — you can’t go wrong with the Carina Nebula!

This wonderful nebula in the deep-south Milky Way rewards any astrophotographer. For this shot I used a 135mm telephoto (Canon’s wonderful f/2 L-series lens) and the Canon 7D camera. The 7D is what I call a “stock” camera, used just as it comes off the dealer shelf. The 7D does a superb job capturing the red nebulosity and its faint outlying bits and pieces. It tends to record these clouds of glowing hydrogen as magenta in tone. By comparison, my other Canon camera is a “filter-modified” 5D MkII. You can see a shot of this same area of sky taken with the 5D MkII a few blogs back under The Best Nebula in the Sky, posted May 6. The 5D MkII’s modification (which replaces the filter in front of the sensor with a new astro-friendly one) allows it to record deep-red wavelengths and picks up more faint nebulosity, registering it more as red in tone. But both images look good and presentable.

This field is rich in objects — not only the main sprawling nebula but nearby star clusters and patches of dark dust clouds. It is one of the finest fields in the sky for binoculars, and this shot approximates the field of view of typical binos. I like to shoot a lot of objects with telephoto lenses — while the main subject is not frame-filling and in your face, it does match (at least in field of view) what you can see in binos, useful for illustrations and observing articles. Of course, the camera picks up  more stuff and colours even your bino-aided eyes can’t see.

This shot is a stack of five 2-minute exposures at f/2.8 with the 135mm telephoto, on the Canon 7D at ISO 1250. I used the little Kenko Sky Memo tracking platform for this, letting it track without any added guiding. It’s tracking was spot on, with nary any star trailing as it followed the target for 20 minutes or so.

— Alan, June 3, 2011 / Image © 2011 Alan Dyer

The Galactic Cathedral


We’re on our last full day in Chile, packing up and sorting out. I’ll finish off my Chile blog series with this parting shot — the entire southern Milky Way from horizon to horizon.

In this view, we’re looking straight up, with the horizon at the edges of the frame of the 15mm fish-eye lens. The glowing starclouds of Sagittarius and Scorpius, seen in close up in the previous blog post, are in the centre of the frame. The Southern Cross is at far right, the Northern Cross at far left.

This scene is a superb way to end a night of southern sky stargazing – just lying back and looking up at the entire panorama of the Galaxy. You really do get the sense that we are indeed living at the edge of the Galaxy, looking off into its bright core, and with its spiral arms wrapping around us.

It’s a galactic cathedral of stars.

– Alan, May 7, 2011 / Image  © 2011 Alan Dyer

The Starfields of Sagittarius and Scorpius


I can’t get enough of this region of sky. I can and do shoot this with every lens I have and with all kinds of framing (horizontally, vertically, or at a rakish angle, like here) and it always looks great.

These are the rich and stunning starfields toward the centre of the Milky Way in Sagittarius (bottom) and Scorpius (at top). Look for the pinkish nebulas dotted along the Milky Way, the bright starclouds, and the dark lanes of interstellar dust. It’s all part of the galactic recycling program that our Milky Way participates in, as stars explode, cast off dust and gas, which then clump into glowing nebulas and form new generations of stars.

I took this shot about 5 a.m. a couple of mornings ago, with this area directly overhead. It’s a stack of six 3-minute exposures with the 35mm lens and Canon 5D MkII camera. I took some shots through a soft focus filter to add the star glows.

– Alan, May 7, 2011 / Image © 2011 Alan Dyer

Springtime Cluster #2: Ancient M67


Poor old M67. Does anyone ever look at this cluster? I tend to ignore it, in favour of its brighter and bigger brother, the Beehive Cluster just to the north. Yet, this smaller cluster ranks with the best of the sky’s open star clusters for richness and brilliance. Only a few showpiece star clusters, like the Beehive and the Pleiades, beat M67.

Located in Cancer, M67 really deserves more respect – even a name! – as it stands out as one of the few prominent deep-sky objects in the otherwise sparse spring sky, at least sparse for bright targets for binoculars or a small telescope. Yes, if you love galaxies, the spring sky is heaven! There are thousands of galaxies to hunt down in spring, but most need a decent-sized telescope to do them justice. By contrast, M67 looks just fine in a small telescope. With a few hundred stars packed into an area the apparent size of the Full Moon this is one rich cluster.

M67 is called that because it is #67 in Charles Messier’s catalog of “things not to be confused as comets.” Messier came across this object in April 1780. Messier ‘s object #67 is one of the few open star clusters not embedded in the Milky Way. Like the Beehive, M67 sits well above the disk of our Galaxy’s spiral arms. We look up out of the plane of the Galaxy to view M67, sitting some 2600 light years away, over four times farther away than its neighbour in Cancer, the Beehive. Thus, M67 looks smaller than the Beehive because it is more distant.

M67 holds the distinction of being one of the oldest star clusters known. It’s been around for over 4 billion years. Its position well above the frenzied traffic jam of our Galaxy’s spiral arms helps M67 stay intact and together, an isolated island of stars in our spring sky.

This image was taken right after the M44 Beehive Cluster shot featured in my previous blog post, using the same gear. So the image scale is the same. You can see how much smaller M67 appears than M44. Because M67 was beginning to sink into the west when I took this, I bumped the camera up to ISO 1600 and used shorter 3 minute exposures and stacked five of them to smooth out noise. The telescope was the little 92mm TMB apo riding on the Astro-Physics 600E mount and flawlessly autoguided with the Santa Barbara Instruments SG-4 autoguider. I really love the SG-4 — just press one button and it’s guiding. True “Push Here Dummy” guiding!

— Alan Dyer, April 2011 / Image © 2011 Alan Dyer

The Neglected Small Magellanic Cloud


It sits not far away in the deep southern sky from its larger counterpart, but it must feel rather inferior and sadly neglected. Pity as this object does have lots to offer.

This is the Small Magellanic Cloud, a satellite galaxy to the Milky Way and a companion to the Large Magellanic Cloud — each is named for Ferdinand Magellan who noted them on his pioneering circumnavigation voyage of the world in the 16th century. The Small Cloud doesn’t contain the number and complexity of nebulas and clusters as does its larger brother, but it does have some lovely offerings, like the complex of cyan-coloured nebulas and related clusters at top.

However, the notable sights in this area of sky aren’t actually part of the SMC. The two globular clusters in the field lie much closer to us. NGC 362 is a nice globular at top, but it pales in comparison (every such object does) next to the amazing object known as 47 Tucanae, or NGC 104, the huge globular cluster at right. It is a wonderful sight in any telescope.

This is a stack of five 7-minute exposures with the Borg 77mm f/4 astrograph and Canon 5D MkII at ISO 800. I took this on my astrophoto trip to Australia in December 2010, a season when this object is ideally placed for viewing. Most times of the year, the SMC is dragging close to the horizon and lost in the murk, as least for shooting. That’s another reason the poor old SMC gets no respect!

— Alan, December 2010 / Image © 2010 Alan Dyer

The Wonder-filled Large Magellanic Cloud


It occupies only a binocular field or two in the sky but … Wow! What a field it is! This is one of the objects that makes a trip to the southern hemisphere for astronomy worth the trek alone. This satellite galaxy of our Milky Way is visible only from south of the equator. It contains so many clusters and nebulas, many in the same telescope field, that just sorting out what you are looking at takes a good star atlas (most don’t plot this region well). This is one of my best shots of the “LMC,” taken on my December Oz trip. It is with the Borg 77mm f/4 astrographic lens/telescope and the filter-modified Canon 5D MkII, that picks up much more red nebulosity (that emits deep red wavelengths) that stock cameras don’t record well.

Even so, I’m always amazed at how so many nebulas in the LMC, and in its smaller counterpart, the nearby Small Magellanic Cloud, record as magenta or cyan, rather than deep red. The most prominent object is the Tarantula Nebula at left of centre. It is an amazing sight in any telescope, especially with a nebula filter.

This is a stack of five 7-minute exposures at ISO 800, with the scope on the AP 400 mount and guided with the SG-4 autoguider. This is a single image, framed to take in all the best stuff of the LMC. But to really get it all in with any detail requires a multi-panel mosaic. I’ve done those on previous trips and was hoping to re-do one on this last trip, with the better, sharper camera, the 5D MkII, and with the LMC higher in the sky than on earlier trips. But the lack of clear nights curtailed my plans.

But I’m happy with this one. Nice and sharp and with oodles of nebulosity. But one can never exhaust what this object has to offer, both for imaging and for just looking with the eyepiece. So there’s always next time!

– Alan, December 2010 / Image © 2010 Alan Dyer