Urban Orion


Urban Nightscape – Orion over Calgary

On a very clear night, Orion shines over the skyline of Calgary.

As I live in the country, it’s not often I shoot the stars from urban sites, and certainly not from downtown Calgary. But the combination of a clear night and a speaking commitment in Calgary provided a chance to see what was possible under ideal conditions.

The lead image is real – I did not paste an image of the sky taken at some other time or place over the skyline image.

However, the sky image is a longer exposure (10 seconds) than the ground (3 seconds) in order to bring out the stars better, while keeping the city lights under control with no overexposure. So it is sort of a high dynamic range blend.

The other factor that helped reveal stars as faint as shown here (fainter than what the naked eye can see) is the use of a light pollution reduction filter (a NISI Natural Night filter) to penetrate the yellow sky glow and provide a more pleasing colour to the sky.

Earlier in the night, during twilight when urban light pollution is not so much of an issue, I shot the waxing crescent Moon setting over the skyline.

Crresent Moon over Calgary

This is a panorama image made from high dynamic range blends of various exposures, to again accommodate the large range in brightness in the scene. But I did not use the NISI filter here.

These images demonstrate how you can get fine astronomy images even from urban sites, with planning and timing.

To that end, I used my favourite app, The Photographer’s Ephemeris, to determine where the sky elements would be as seen from a couple of viewpoints over the city that I’ve used in the past.

The blue spheres in the left image of TPE in its Night mode represent the Milky Way. That chart also shows the direction toward Orion over the city core.

The right image of TPE in its Day mode shows the position of the Moon at 6 pm that evening, again showing it to the left of the urban core.

Other apps are capable of providing the same information, but I like TPE for its ease of use.

Clear skies!

— Alan, January 20, 2018 / © 2018 Alan Dyer / AmazingSky.com 

 

Red Rivals in Scorpius


Red Rivals in Scorpius

Mars outshines his rival red star Antares in the heart of the Scorpion.

This was the view last night from my observing site in Australia, of red Mars shining near the red star Antares, whose very name means “rival of Mars.” But as Mars nears its closest approach to Earth next month it is already far brighter than Antares, easily winning the rivalry now.

The view takes in the head of Scorpius, one of the most colourful areas of the night sky when photographed in long exposures. Uniquely, Antares illuminates a nearby dust cloud with its light which is more yellow than red.

Other dust clouds reflect the blue light of hot young stars in this section of the Milky Way. Red nebulas are emitting their own light from glowing hydrogen.

The area around Antares is also streaked with lanes of dark dust that absorb light and at best appear a dull brown.

Mars reaches its closest point to Earth since 2005 on May 30. All through May and June Mars will shine as a brilliant red star near Antares. A telescope will provide the best view of the red planet we’ve had in a decade.

Saturn and Mars in Scorpius
This is a stack of 4 x 3 minute exposures with the 135mm telephoto lens at f/2.8 and filter-modified Canon 5D MkII at ISO 1600, shot April 14, 2016 from Tibuc Cottage, Australia.

While you are in the area aim your telescope a little to the east to catch Saturn, also in the area, though technically over the border in the constellation of Ophiuchus the Serpent Bearer.

In the view above, Saturn is the bright “star” to the left of Mars. Saturn reaches its closest to Earth in early June. Its rings are now wide open and a spectacular picture postcard sight in any telescope.

Scorpius Rising in Moonlight
This is a stack of 2 x 30-second exposures for the sky and ground, both tracked, plus a 30-second exposure through the Kenko Softon A filter to add the star glows to make the constellation pattern stand out. All with the 35mm lens at f/2 and Canon 6D at ISO 1600. Taken from Tibuc Cottage, Australia.

This final view shows Mars and Saturn rising with Scorpius in the moonlight from two nights ago. From my current latitude of 32° south, Scorpius comes up on his side.

— Alan, April 15, 2016 / © 2016 Alan Dyer  / www.amazingsky.com

Under the Southern Cross


Southern Milky Way Over OzSky Star Party

The Southern Cross, the iconic constellation of the southern sky, shines high in the south on austral autumn nights.

I’m in one of my favourite places, Australia, in particular at its self-proclaimed “astronomy capital,” Coonabarabran in New South Wales. Down the road from me is the Siding Spring Observatory.

But for 3 weeks I’m using my own telescope gear to observe and photograph the fabulous southern skies.

For part of my time here I’m attending the annual OzSky Star Party, a small and rather exclusive event for observers from around the world who come here to revel in celestial wonders visible only from southern latitudes.

The lead image at top is a 7-panel panorama of the star party in action, on the grounds of the Warrumbungles Mountain Motel, with a dozen or more large and premium telescopes set up for our use.

Overhead is the arch of the southern Milky Way, with the Southern Cross here at its highest about local midnight now in early April at the start of autumn. Below the Milky Way is the Large Magellanic Cloud, a companion galaxy to the Milky Way, itself a superb target for telescopes.

To the far right in the Milky Way is Sirius amid the gum trees, and the stars of Canis Major diving into the west. To the far left are the bright star clouds of Scorpius and Sagittarius rising in the east, bringing the glowing core of our Galaxy high into the austral sky. Bright Mars and Saturn shine in and around Scorpius.

This is a view of the Milky Way everyone should see – it is should be one of the top items on any amateur astronomer’s bucket list.

Star Trails over the OzSky Star Party
Circumpolar star trails over the OzSky star party near Coonabarabran, NSW, Australia, on April 3, 2016. This is a stack of 49 frames, each 45 seconds at f/2.8 with the 15mm fish-eye lens on the Canon 6D at ISO 4000. The ground comes from three frames in the sequence. Stacked with Advanced Stacker Plus actions using Streaks mode.

Here, above, I’ve stacked images from a time-lapse to create a star trail scene with the stars of the southern sky rotating about the blank South Celestial Pole. Again, the Southern Cross is at top.

Southern Milky Way from Alpha Cen to False Cross
The deep south Milky Way from Alpha and Beta Centauri (at left) to the False Cross in Vela and Carina (at right). This is a stack of 5 x 4 minute exposures at f/2.8 with the 35mm Canon L-series lens and filter-modified Canon 5D MkII at ISO 1000, with an additional similar exposure layered in taken through the Kenko Softon A filter to provide the star glows. Tracked on the iOptron Sky Tracker. 

This view, above, focuses on the Milky Way of the deep south, from Vela to Centaurus, passing through Carina and Crux, with the bright Carina Nebula, the Southern Cross, and the dark Coal Sack front and centre.

Mosaic of Crux, the Southern Cross
A 3-panel mosaic of the Southern Cross, Crux, shot April 5, 2016 from Tibuc Cottage, Coonabarabran, NSW, Australia. This is a moasic of 3 panels, each a stack of 4 x 4-minute exposures with the Borg 77mm f/4 astrograph and filter-modified Canon 5D MkII at ISO 1600. Stacked and stitched in Photoshop.

Here I zoom into the Southern Cross itself, in a mosaic of 3 panels to cover the smallest constellation using a high-resolution astrograph, a 300mm f/4 lens. The Coal Sack is at lower left while numerous star clusters lie embedded within and around the Cross, including the famous “Jewel Box” at left, next to Beta Cruxis, aka Becrux.

The Southern Milky Way and Magellanic Clouds
The deep southern Milky Way arching across the sky, from Puppis and Vela at upper right, to Centaurus at lower left. The two Magellanic Clouds are at lower centre, with the Large Cloud at top. This is a stack of 5 x 1.5-minute exposures, all tracked on the iOptron Sky Tracker, at f/2.8 with the 15mm fish-eye lens, and Canon 5D MkII at ISO 3200. The ground comes from just one of the tracked exposures to minimize blurring. Taken from the Tibuc Gardens Cottage near Coonabarabran, NSW, Australia on March 30, 2016.

I shot the Crux mosaic from my cottage site at Tibuc Gardens, a superb dark sky site and home to a new cottage built after the devastating bush fires of 2013 which destroyed all the other cottages I had stayed at in previous years.

There’s much more to come, as I rapidly fill up my hard drive with time-lapses and deep-sky images of the southern sky. I already have several blogs worth of images processed or about to be. In the meantime, check my Flickr site for the latest images hot off the hard drive and uploaded as best my Oz internet connectivity allows.

— Alan, April 7, 2016 / © 2016 Alan Dyer / www.amazingsky.com

 

A Panorama of the Spring and Winter Sky


Winter and Spring Sky Panorama

I present a sweeping panorama of the winter and spring stars on a February night. 

The lead image is a panorama I shot last Saturday, February 27 that takes in about 200° of sky from northeast to west, and nearly to the zenith. It encompasses most of the northern spring and winter stars and constellations.

I’ve added the labels to help you pick out the celestial highlights. The winter sky, containing Orion as the central constellation, is at right setting into the west. This area of sky contains a rich collection of bright stars and identifiable constellations.

The left side of the sky contains the spring constellations, now coming into view in the east. Note how that area of sky is sparsely populated by bright stars. You can see the Big Dipper, Regulus in Leo, and Arcturus rising at lower left.

The reason for the difference is the Milky Way – you can see it at right arcing up from the southern horizon passing by Orion and through Gemini, Taurus and Auriga. In that direction we are looking into the outlying spirals arms of our galaxy, toward rich areas of star formation.

To the east, at left, we are looking at right angles out of the plane of our spiral galaxy, toward the galactic North Pole, here just left of Leo. In that direction there are very few bright stars between us and the starless depths of intergalactic space. The spring sky is rather blank compared to the rich winter sky.

But you can see Jupiter, the brightest object in view here, and now prominent in the evening sky.

Note one other subtle glow just above Jupiter. That diffuse glow is the Gegenschein, caused by sunlight reflecting off interplanetary dust opposite the Sun in our solar system and in the plane of the ecliptic.

Jupiter is just east (left) of the Gegenschein here, as Jupiter was then just over a week before its date of opposition, March 8. By then the Gegenschein will have moved to superimpose right over Jupiter, as both then lie opposite the Sun.

Winter and Spring Sky Panorama

I shot this scene from home on February 27, 2016, using the new iOptron iPano motorized “gigapan” unit, which I programmed to move and shoot 36 exposures with the Canon 5D MkII and 35mm lens, arranged in 4 rows high with 9 panels wide in each row from east to west. The result is a huge mosaic, 24,000 by 10,000 pixels.

Each exposure was 25 seconds at f/2 and at ISO 3200. The camera was not tracking the sky. I stitched the 36 segments with PTGui using its Spherical Fisheye projection. The image has black margins but I think the circular format is more suggestive of the spherical dome of the sky above and around you. But that’s me, a longtime planetarium show producer.

Next time I will shoot the zenith cap images as well!

— Alan, February 29, 2016 / © 2016 Alan Dyer / www.amazingsky.com

 

Mosaic of the Autumn Constellations


Mosaic of the Northern Autumn Constellations

I present a horizon-to-zenith panorama of the pantheon of autumn constellations.

Yes, I know it’s winter, but as it gets dark each night now in early January the autumn stars are still front and centre. I took the opportunity during a run of very clear nights at home to shoot a panorama of the autumn sky.

It is a mosaic that sweeps up the sky and frames many related Greek mythological constellations:

• from the watery constellations of Aquarius, Pisces, and Cetus at the bottom near the horizon…

• to Pegasus and Aries in mid-frame…

• on up to Andromeda and Perseus at upper left…

• and finally Cassiopeia and Cepheus at the top of frame embedded in the Milky Way overhead. The Andromeda Galaxy, M31, is just above centre.

Mosaic of the Northern Autumn Constellations (with Labels)

Here, I’ve labeled the participating constellations, though only a few, such as the “square” of Pegasus and the “W” of Cassiopeia, have readily identifiable patterns.

Most of these constellations are related in Greek mythology, with Princess Andromeda being the daughter of Queen Cassiopeia and King Cepheus, who was rescued from the jaws of Cetus the Sea Monster by Perseus the Hero, who rode on Pegasus the Winged Horse in some accounts.

Zodiacal Light brightens the sky at bottom right in Aquarius, and angles across the frame to the left.


 

TECHNICAL:

I shot this from home on a very clear night January 2, 2016 with the Zodiacal Light plainly visible to the naked eye.

This is a mosaic of 5 panels, each a stack of 5 x 2 minute exposures, plus each panel having another stack of 2 x 2 minute exposures blended in, and taken through the Kenko Softon filter to add the fuzzy star glows to make the constellations stand out.

All were shot with the 24mm Canon lens at f/2.8 and Canon 5DMkII at ISO 1600. All tracked on the AP Mach One mount.

All stacking and stitching in Photoshop CC 2015. Final image size is 8500 x 5500 pixels and 3.6 gigabytes for the layered master.

– Alan, January 3, 2016 / © 2016 Alan Dyer / www.amazingsky.com

 

A Panorama of the Entire Northern Milky Way


Panorama of the Northern Milky Way

In a sweeping panorama, here is the entire northern hemisphere Milky Way from horizon to horizon.

This is the result of one of the major projects on my recent trek to Arizona and New Mexico – a mosaic of images shot along the Milky Way over several hours.

The goal is a complete 360° panorama of the entire Milky Way, and I’ve got most of the other segments in previous shoots from Alberta, Australia and Chile. But I did not have good shots of the northern autumn segments, until now.

The panorama sweeps from Cygnus (at top, setting in the western sky in the evening), across the sky overhead in Perseus, Auriga and Taurus (in the middle), and down into Orion, Canis Major, and Puppis (at bottom, low in the southern sky at midnight).

The view is looking outward to the near edge of our Milky Way, in the direction opposite the centre of our Galaxy. In this direction the Milky Way becomes dimmer and less defined. Notable are the many red H-alpha emission regions along the Milky Way, as well as the many lanes of dark interstellar dust nearby and obscuring the more distant stars.

However, a diffuse glow in Taurus partly obscures its Taurus Dark Clouds — that’s the Gegenschein, caused by sunlight reflecting off cometary dust particles directly opposite the Sun and marking the anti-solar point this night, by coincidence then close to galactic longitude of 180° opposite the galactic centre.

Panorama of the Northern Milky Way (with Labels)

Here I provide a guided map of the mosaic. Orion is at lower right, while the Pleiades and Andromeda Galaxy lie near the right edge. The Andromeda Galaxy is the only thing in this image that is not part of the Milky Way.

The bright star Canopus is just rising at bottom, in haze. Vega and Altair are just setting at the very top. So the panorama sweeps from Altair to Canopus.

The sky isn’t perfect! Haze and airglow in our atmosphere add discolouration, especially close to the horizon. In my final 360° pan, I’ll use only the central portions of this panorama.

Now let’s put the horizon-to-horizon panorama into cosmic perspective…

Illustration of the Northern Milky Way Panorama

In this diagram, based on art from NASA’s Spitzer Space Telescope Institute, I show my Northern Milky Way Panorama in perspective to the “big picture” of our entire Galaxy, using artwork based on our best map of how our Galaxy is thought to look.

We are looking in a “god’s eye” view across our Galaxy from a vantage point on the far side of the Galaxy.

Where we are is marked with the red dot, the location of our average Sun in a minor spiral arm called the Orion Spur.

The diagram places my panorama image in the approximate correct location to show where its features are in our Galaxy. As such it illustrates how my panorama taken from Earth shows our view of the outer portions of our Galaxy, from the bright Cygnus area at right, to Perseus in the middle, directly opposite the centre of the Galaxy, then over to Orion at left.

The panorama sweeps from a “galactic longitude” of roughly 90° at right in Cygnus, to 180° in Perseus, over to 240° in Orion and Canis Major at left.

In the northern autumn and early winter seasons we are looking outward toward the outer Perseus Arm. So the Milky Way we see in our sky is fainter than in mid-summer when we are looking the other way, toward the dense centre of the Galaxy and the rich inner Norma and Sagittarius arms.

Yet, this outer region contains a rich array of star-forming regions, which mostly show up as the red nebulas. But this region of the Milky Way is also laced with dark lanes of interstellar “stardust.”

NOTE:

For larger images, see my Flickr site at https://www.flickr.com/photos/amazingsky/

TECHNICAL:

The panorama is composed of 14 segments, most being stacks 5 x 2.5-minute exposures with the filter-modified Canon 5D MkII at ISO 1600 and 35mm lens at f/2.8.

The end segments near the horizons at top and bottom are stacks of 2 x 2.5-minute exposures.

Each segment also has an additional image shot through a Kenko Softon filter to add the star glows, to make the bright stars show up better.

The camera was oriented with the long dimension of the frame across the Milky Way, not along it, to maximize the amount of sky framed on either side of the Milky Way.

The camera was on the iOptron Sky-Tracker. I shot the segments for this pan from Quailway Cottage, Arizona on December 8/9, 2015, with the end segments taken Dec 10/11, 2015. I decided to add in the horizon segments for completeness, and so shot those two nights later when sky conditions were a little different.

— Alan, December 19, 2015 / © 2015 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