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

 

A Cosmic Christmas Wreath


IC 1396 & Garnet Star in Cepheus

A cosmic Christmas wreath glows in the sky, adorned by a celestial garnet.

This nebula, known as IC 1396, shines in the constellation of Cepheus the king, now high overhead on early winter evenings in the northern hemisphere. It’s a bubble of gas blown by new stars amid the interstellar wreath.

At top, shining like a Christmas light on the wreath, is an orange star. This is Mu Cephei, also known as the Garnet Star. It’s a red supergiant, roughly 1,500 times bigger than our Sun. If it replaced our Sun at the centre of our solar system it would engulf all the planets out to and including Jupiter.

Be happy Mu sits 1,000 light years away!

Happy holidays! And happy solstice. Winter arrives in the northern hemisphere at 6:03 p.m. EST on Sunday, December 21. That’s the shortest day and longest night of the year, for all those north of the equator.

– Alan, December 20, 2014 / © 2014 Alan Dyer

The Head of the Celestial Scorpion


 

Scorpius Head & Antares (135mm 5DII) v2The head of Scorpius is laced with colourful nebulas, both bright and dark. 

This is an image from two nights ago, from the dark skies of southeast Arizona. It takes in the head of Scorpius, from yellow Antares at lower left as the heart of the Scorpion, to the blue stars at right that mark his head.

The remarkable feature of this region of sky is its colour. No where else in the sky do we see (or I should say, does the camera see) such a spectrum of colourful nebulas. Dark brown lanes run down from the constellation Ophiuchus at left. They meet up with a yellow patch of nebulosity caused by dust reflecting the yellow-orange light of the giant star Antares.

Hot blue stars light up other dusty patches, while the magenta nebulas are created by gas emitting light, not just reflecting light from nearby stars.

A close-up of the region, shot in Australia last month, appears in my blog post from April 17, Stars Scenes in Scorpius. The image above, shot with a 135mm telephoto lens, takes in an area of sky that typical binoculars would frame.

But the eye sees only a hint of the detail, and none of the colour, hidden in the heart of Scorpius.

– Alan, May 6, 2014 / © 2014 Alan Dyer

 

Stellar Graveyard in Vela


Vela Supernova Remnant (77mm 5DII)

This is what’s left of a star that exploded in ancient times.

This is the Vela Supernova Remnant, an object in the southern sky in the constellation of Vela the Sail. The wispy tendrils of magenta and cyan are all that’s left of the outer layers of giant star that exploded about 12,000 years ago.

Cluttering the field at left are amorphous patches of star-forming nebulosity that are part of the much larger Gum Nebula complex.

The supernova was only about 800 light years away so it would have been a brilliant sight in the sky to neolithic observers, far outshining any other stars. But no record exists of anyone seeing it.

The star didn’t destroy itself completely – its core collapsed to form a pulsar, an ultra-dense ball of neutrons, in this case spinning about 11 times a second. The pulsar is in this field but it’s much too faint to show up in visible light.

I shot this earlier this month from Australia where Vela sails directly overhead. The field is about 6° by 4°, the amount of sky framed by high power binoculars. The brighter parts of the Vela Remnant can be picked out in large amateur telescopes – I’ve seen bits of it in my 10-inch telescope – but this is certainly a challenging object to see, even with aided eyes.

— Alan, April 23, 2014 / © 2014 Alan Dyer

 

 

Star Scenes in Scorpius


Scorpius Overhead (50mm 5DII)

Scorpius, one of the most photogenic of constellations, contains a wealth of amazing sky sights.

My trip to the land down under is coming to an end but I’m still working through the dozens of deep-sky images I was able to take under the southern stars. The wide-field scene above takes in all of Scorpius, shot with the constellation sitting directly overhead in the pre-dawn hours of an austral autumn. You can trace the scorpion’s winding shape down from his head and claws at top, to his curving stinger tail at bottom.

M6 and M7 Star Clusters in Scorpius (77mm 5DII)

Off the stinger of the scorpion shine two naked-eye star clusters, Messier 6 and 7 (the close-up photo above). M6 is the Butterfly Cluster, seen here sitting in a dark region of the Milky Way at upper right. Its companion, M7, a.k.a. Ptolemy’s Cluster at left of the frame, is lost amid the bright star fields  that mark the direction of the galactic core.

NGC 6334 Cat's Paw Nebula (77mm 5DII)

In the curving tail of the scorpion lie two patches of nebulosity. At upper left is NGC 6357, but the triple-lobed NGC 6334 at bottom right is also known as the Cat’s Paw Nebula.

False Comet NGC 6231 Area (77mm 5DII)

Further up the tail of the scorpion sits this fabulous region of space that is a stunning sight in binoculars. NGC 6231 is the blue star cluster at bottom, which garnered the name The False Comet Cluster back in early 1986 when many people mistook its fuzzy naked eye glow for Comet Halley then passing through the area. The camera reveals the region filled with glowing hydrogen gas.

Antares & Rho Ophiuchi Area (77mm 5DII)

But the standout region of Scorpius lies at its heart. Here, the yellow-orange star Antares lights up a dusty nebula surrounding it, reflecting its yellow glow. At top, another dusty nebula surrounds the star Rho Ophiuchi, reflecting its blue light. Glowing hydrogen gas adds its characteristic magenta tints. This is one of the most colourful regions of the Milky Way.

I shot these images with 50mm normal and 300mm telephoto lenses two weeks ago during the OzSky Star Safari near Coonabarabran, NSW, Australia. For all I used a filter-modified (by Hutech) Canon 5D Mark II camera.

— Alan, April 17, 2014 / © 2014 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

 

The Summer Triangle Stars


Summer Triangle in the Milky Way

The trio of Summer Triangle stars flank the Milky Way in the dying days of summer.

I shot the featured image above two nights ago on a perfect late summer night from home. Skies were dark and transparent, with no aurora and little airglow to taint the sky.

The image takes in the Summer Triangle stars of Vega (top), Deneb (left) and Altair (bottom). Vega and Altair straddle the summer Milky Way, but Deneb lies right in the thick of it, way down the Local Arm that we live in. Vega and Altair are nearby normal stars, only 25 and 16 light years away. But Deneb is a blue supergiant, shining from 1400 light years away, and one of the most luminous stars in the catalog.

The Milky Way through this area of sky is riven by twisting lanes of interstellar dust. A particularly dark patch sits above Deneb at top left. Then below Deneb the Milky Way gets split by the Great Rift that continues down into Aquila and Ophiuchus at lower right.

All along this part of the Milky Way, particularly around Deneb, the camera picks up a string of glowing red nebulas where stars are forming. The red comes from hydrogen atoms emitting deep red light, as hydrogen is wont to do.

Summer Milky Way from Backyard (Sept 9, 2013)

This image is from a couple of nights earlier. I used a wider angle lens to take in the full sweep of the summer Milky Way, from Sagittarius skimming the horizon, to Cassiopeia past the zenith at the top. You can see the Summer Triangle in the top half of the image, the part of the sky now overhead on early September nights from the northern hemisphere.

I took both shots with a filter-modified Canon 5D MkII placed on a little iOptron SkyTracker for tracked long exposures (4 to 5 minutes). The main image was with a 24mm Canon lens, the bottom image with a 14mm Rokinon lens.

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

 

Last of the Summer Milky Way


Milky Way over Mountains at Waterton Lakes (Aug 31, 2013)

The summer Milky Way sets behind the peaks of Waterton Lakes National Park, signalling an end to summer.

This was the scene last Saturday night, on a perfect summer night in the Rockies. The glorious starfields of the summer Milky Way are setting behind the mountains.

The Small Sagittarius Starcloud is just above the mountain ridge while above it are the red patches of the Swan and Eagle Nebulas.

Farther up the Milky Way, stars brighten into another starcloud, the Scutum cloud, flanked by two dark lanes of dust. Above it shine the stars of Aquila, Ophiuchus, Lyra, and southern Cygnus. The two bright stars are Altair (below) and Vega (top right).

Summer Milky Way over Mountains (Aug 31, 2013)

This is an alternative view of the same scene, with the camera in “landscape” orientation.

I took both from a pull-off on the Red Rock Canyon road in Waterton. Each image is a stack of four 3-minute exposures, each tracking the stars with the camera on an iOptron SkyTracker.

The Milky Way from Canada just doesn’t get any clearer or the skies any darker.

– Alan, September 3, 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

 

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

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

 

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 Colourful Clouds of Orion – #2


The Nebulas of Orion v2

Swirls of pink, red and blue nebulas surround the Belt and Sword of Orion the Hunter.

For this closeup of Orion I used a 135mm telephoto lens under dark Australian skies to grab long exposures to reveal not only the bright Orion Nebula at bottom in Orion’s Sword, but also the Horsehead Nebula (below the left star of Orion’s Belt), Barnard’s Loop (at left) and the mass of red nebulosity between the Loop and the Belt & Sword. At right is a faint blue nebula reflecting the light of the hot blue stars in the area.

This is a gorgeous area of sky for the camera, but only the brightest nebulas, the tip of the cosmic iceberg, are visible to the eye even with the aid of a telescope.

– Alan, December 19, 2012 / © 2012 Alan Dyer

 

The Colourful Clouds of Orion – #1


Orion from Australia (50mm 5DII)

The constellation Orion is a hotbed of star formation, from masses of colourful clouds.

I shot this portrait of Orion the Hunter a few nights ago in Australia where Orion stands upside down compared to our view from up north. But I’ve turned around the photo here to put him right side up with head at the top and feet at the bottom.

The three stars in a row in the middle are his famous Belt stars. Below shines the nebulas that outline his Sword, among them the Orion Nebula, the subject of an earlier post last week

The giant arc is Barnard’s Loop, a bubble blown in space by the winds from hot new stars. The bubble around Orion’s head at top is a similar interstellar bubble. Most stars here are blue-white and hot, but the distinctively orange star is the red giant Betelgeuse, a good candidate for a supernova explosion.

Orion stands high in the sky at midnight these nights, summer here in Australia, but winter at home in Canada.

– Alan, December 19, 2012 / © 2012 Alan Dyer

 

Remains of a Star: The Vela Supernova Remnant


Vela Supernova Remnant and Gum Nebulas

Amid a maze of glowing nebulas sits a tracery of magenta and cyan that was once a star.

This image takes in the Vela Supernova Remnant. You can see it as the lacework of gas in the centre of the field. Oddly enough, it sits in the middle of the vast Gum Nebula, the subject of my previous post, an object also thought to be a supernova remnant but one much older and closer. The Vela Supernova Remnant here likely comes from a supergiant star that exploded about 10,000 years ago. It, too, would have been quite a sight to the earliest of civilizations.

The field in the southern constellation of Vela also contains many other classic red and pink nebulas, but ones that are forming new stars, not the remains of dead ones. Most carry designations from astronomer Colin Gum’s catalog from the 1950s and have no numbers from the more familiar NGC or IC catalogs amateur stargazers refer to in their scanning of the skies. Yet, these Gum nebulas show up easily in photos.

I used a 135mm telephoto lens to take this image and it encompasses a field similar to what binoculars would frame. Except, it takes long exposure photos to show these nebulas. I looked last night at the Vela SNR with my 25cm reflector telescope and could just barely see the main arc of nebulosity as a grey ghost in the eyepiece. And that was under perfect dark Australian sky conditions.

– Alan, December 18, 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 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

 

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

Star Birth Site


In contrast to last Saturday’s post, Star Death Site, this is a place where stars are born.

This magenta cloud is where dozens of new stars are forming. One centre of star formation is the finger at right jutting into the hollowed out core of the nebula. Ultra-violet radiation from nearby hot stars is eroding away this dark finger of dust and gas, causing its rim to glow. This is a feature similar to the famous “Pillars of Creation” depicting in Hubble Space Telescope views of another nebula, the Eagle Nebula. However, this giant wreath of hydrogen 3000 light years away has no name, just the catalog number IC 1396. It’s in Cepheus, high in the northern autumn sky.

An added attraction of the scene is the orange star at top, Herschel’s Garnet Star, a.k.a. mu Cephei. This red supergiant is one of the largest stars known. If it replaced our Sun the Garnet Star would engulf all the planets out to Jupiter. Including its profuse radiation emitted in the infrared, the Garnet Star outshines the Sun by 350,000 times. It is squandering its energy so quickly this supergiant is destined to explode as a supernova, perhaps leaving behind a remnant like the Veil Nebula I described in that earlier blog from a few days ago.

These deep space wonders are all part of the great cycle of stardust that fuels the Galaxy.

– Alan, September 25, 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

The Northern Nebulas of the Milky Way


This is the prime celestial real estate above us now on northern summer nights.

This wide-angle shot takes in the Milky Way from Cygnus at right to Perseus at left, an area populated by lots of nebulas, both bright and dark. A couple of previous posts (The Subtle Shades of Cepheus and The Dark Clouds of Cygnus) featured close-up views of sections of this sky, the areas at centre in this wider context image in northern Cygnus and southern Cepheus.

At bottom is the elliptical glow of the Andromeda Galaxy, another “milky way” beyond ours.

I boosted the contrast and colour more than I normally do for astrophotos, to punch out the nebulas and the subtle dark lanes of dust that permeate this part of the Milky Way. I shot this last weekend from the star party in Cypress Hills, Saskatchewan. With three clear nights it was a productive weekend!

– Alan, August 26, 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

 

The Dark Clouds of Cygnus


Stare into the starfields of Cygnus and ponder what lies undiscovered in our part of the Milky Way.

You are looking down the spiral arm we live in, into clouds of stars seemingly packed together. Every one of those specks is a sun like ours. With planets? Very likely, as we now know.

Amid the stars float glowing red clouds of hydrogen gas. The North America Nebula shines at lower right.

Snaking northward from the “arctic” region of the bright nebula is a river of dust that broadens into a delta of dark nebulosity. Once thought to be holes in the sky allowing us to see deeper into space, we know now that these dark nebulas are really foreground dust clouds filled with the soot of dying stars, carbon dust that absorbs starlight and obscures the more distant parts of the Milky Way.

This dust cloud is called Le Gentil 3, named for the 18th century French astronomer who first noted its position in the sky. Le Gentil’s dust cloud is one of the easiest features of the summer Milky Way to see. Look north of Deneb, the bright star at the right of the image, and with the unaided eye on a dark moonless night you’ll see what looks like a dark hole in the Milky Way. That’s Le Gentil 3.

I use this dust cloud as a measure of sky brightness. On a truly dark night, Le Gentil 3 looks darker than any other area of sky, even relatively starless regions off the Milky Way. Most of the sky brightness we see from a dark site is really starlight. But Le Gentil’s proximity and opaqueness makes it appear darker than the more distant starlit sky background.

This image covers about the width of a binocular field. I shot it from the Cypress Hills in Saskatchewan this past weekend, using the Canon 5D MkII at ISO 1600 and Canon 135mm telephoto lens at f/2.8. It’s a stack of 10 five-minute exposures.

— Alan, August 22, 2012 / © 2012 Alan Dyer

Continent in the Sky


Shining overhead on northern summer nights right now is the blue supergiant star Deneb, in Cygnus. Nearby glow the magenta clouds of the North America Nebula.

This image shot with a telephoto lens takes in roughly the same field of view as a pair of binoculars. But being a long time exposure it reveals much more of the faint nebula than even the aided eye can see. However, even binoculars will show a greyish cloud near Deneb in roughly the shape of North America. It is actually a continent of stars and hydrogen gas, glowing with hydrogen’s characteristic magenta colour, a mix of deep red and blue emission lines. The gas may be electrified into glowing by the searing radiation from the star Deneb, some 1400 light years away from Earth.

I shot this on a July night, with some haze passing by during some of the exposures. The haze added the photogenic glows around the stars.

— Alan, August 8, 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

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

 

Into the Heart of the Scorpion


Here we peer into the heart of Scorpius, to a place where the sky is painted with pastel hues unlike anywhere else in the heavens.

The yellow star at bottom is Antares, the cool supergiant star that marks the heart of the Scorpion. To the right is Messier 4, a globular cluster of thousands of stars. Wrapping the entire field are shrouds of dust, reflecting the yellow light of Antares and the blue light of hotter stars above, such as Rho Ophiuchi at top right. Glowing hydrogen gas clouds add the magenta hues.

The remarkable feature of this field are the dark fingers, clouds of dark interstellar stardust glowing with a dim yellowy-brown hue. In places the clouds become more opaque and intense, blocking any light from background stars. Those clouds must be close by in our galactic spiral arm because few stars lie between us and their dark masses. Estimates put them about 400 light years away.

The entire region is a busy factory of star making, one of the closest to our Sun. Chances are our solar system formed in a similar star factory 5 billion years ago, one that has long since dissolved away and dispersed around the Galaxy.

Like the previous shot, this is a Canon 7D/135mm telephoto image in a stack of six 2-minute exposures, taken from Chile in early May. I find it remarkable that with digital cameras just 2-minute exposures not only bring out the dark nebulas, but actually show them with colour and tonality. In the old days, film shots 20 minutes long only ever showed them as a mass of underexposed and featureless black.

— Alan, June 16, 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 Best Nebula in the Sky


What a great field this is to explore with binoculars. The image here takes in about the same area of sky as most binoculars and look what it contains! Arguably, the best nebula in the sky: the Carina Nebula, and the best open star cluster: the Football Cluster (aka NGC 3532) to the left of the main nebula. And then there’s the Southern Pleiades star cluster, IC 2602, below the nebula, and lots more besides.

This one field is reason enough to travel to the southern hemisphere for stargazing.

I shot this last night, May 6, 2011, using a 135mm telephoto lens at the modified Canon 5D MkII camera. The filter modification allows the camera to pick up a lot more of the faint wispy bits of glowing nebulosity. This is a stack of four 3-minute exposures, with two of the exposures shot through some thin cloud (the first we saw all week!), adding the subtle but photogenic glows around the stars.

– Alan, May 7, 2011 / Image © 2011 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

Orion’s Sword Defeated!


Every astrophotographer has an object or field that seems to defy capture. For me, shooting the Sword of Orion has always been beset by haze, tints from light pollution and low altitude — something has always gone wrong. At last I managed to get a good shot of the region. It was a priority for me on my Australia trip of December 2010. Even though I ended up with only 2 clear nights to do any  serious shooting, out of 15 I was there, I really wanted to grab this area, while Orion was high in the north, and higher in altitude than I can get it from home, so less hindered by sky gradient tints.

This is a shot with the wonderful Borg 77mm f/4 astrograph (which is tack sharp across the field) and the modified full-frame Canon 5D MkII camera — both items purchased from Hutech Scientific, a great source of astrophoto gear. This is a stack of five 7-minute exposures at ISO 800, processed in Photoshop CS5.

– Alan, December 2010 / Image © 2010 Alan Dyer