Cassiopeia – The Amazing Sky

January 3, 2016January 3, 2016

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.

November 30, 2015November 30, 2015

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!

September 26, 2014

Autumn Stars Rising over Dinosaur Park

The autumn constellations rise into a colourful sky at Dinosaur Provincial Park, Alberta.

Last night the sky started out beautifully clear but as it got darker it was apparent even to the eye that the sky wasn’t really dark, despite the lack of any Moon.

The camera captured the culprit – extensive green airglow, to the east at right. A faint aurora also kicked up to the north, at left, adding a red glow. Light pollution from gas plants nearby and from Brooks 50 km away added yellow to the sky scattered off haze and incoming cloud.

The sky colours added to the scene of the autumn constellations of Cassiopeia, Andromeda, Perseus and Pegasus rising in the east. The Andromeda Galaxy is at centre. The Pleiades is (are?) just rising over the hill.

This is a composite of five stacked and tracked exposures for the sky (with the camera on the Star Adventurer tracking mount) and four stacked but untracked exposures I took at the end of the sequence for the sharp ground (I just turned the tracker motor off for these).

October 11, 2013

A Star-Filled Scene in Cassiopeia

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.

August 20, 2013August 20, 2013

Cassiopeia Rising in the Badlands

The stars of Cassiopeia rise behind hoodoo formations in the Alberta Badlands.

I took this Sunday night, August 18, as part of my shoot at Dinosaur Provincial Park. This is a particularly striking pair of hoodoos at the start of the Badlands Trail where I’ve been meaning to take some moonlit nightscapes for a couple of years.

This night’s conditions were perfect, with the “W” of Cassiopeia nicely placed, and the Moon providing excellent cross-lighting, under a clear blue sky, for the contrasting colours of earth and sky.

June 26, 2013June 26, 2013

Thunderstorm in the Moonlight

A thunderstorm rolls across the northern horizon with the stars of Cassiopeia and Andromeda rising.

This was a perfect night for storm shooting. The storm was far enough away to not engulf me in rain and wind, but close enough to show detail and reveal its bolts of lightning. A waning gibbous Moon shone in the south lighting up the storm clouds to the north and turning the sky blue.

Meanwhile the stars of Cassiopeia, Perseus and Andromeda were rising behind the storm clouds, a nice contrast of Earth and sky.

I’ve been after a confluence of circumstances like this for a few years. An aurora to the northeast would have been nice as well. But you can’t have everything!

May 29, 2013May 30, 2013

Moonlight on the Hoodoos

The stars shine in a bright moonlit sky over the Alberta Badlands.

My feature image above is one of several still frames I took at the end of 4-hour photo shoot last Sunday at Dinosaur Provincial Park. The nearly Full Moon provides the illumination on an eroded landscape originally cut by water from retreating ice age glaciers.

But the volcanic ash layers hold treasures much older, from 70 million years ago. This area contains the world’s richest collection of late Cretaceous fossils of dinosaurs and other flora and fauna from near the end of the dinosaurs’ reign.

The movie below is a 300-frame time lapse of the stars turning behind the hoodoos. It’s a dolly shot, using the Dynamic Perception Stage Zero rail and controller.

The system works very well, but such shots demand a site with a suitable immediate foreground, as well as a good view to the distant sky. It is the parallax motion between foreground and background that makes a dolly move interesting.

I planned this shot to begin at twilight and continue as the sky was darkening, then into the rest of the night with the Moon rising and lighting up the landscape. The moving clouds were perfectly timed and placed!

October 7, 2012October 7, 2012

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.

August 24, 2012August 24, 2012

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!

August 4, 2012August 4, 2012

Driving to Andromeda

Are we there yet? It would take a long time to get to the end of this road.

A road in Banff appears as if it is heading toward the autumn constellations rising over the peaks of the Fairholme range in the Canadian Rockies. The stars of Andromeda (centre), Pegasus (right), Perseus (left), and Cassiopeia (above left) make up the panorama of mythological heroes populating the northern autumn sky. In the sky above the road the small smudge of the Andromeda Galaxy is visible, shining from 2.5 million light years away. A faint aurora at left adds to the moonlit scene.

I shot this Sunday, July 29, moments after taking the image in the previous blog, which was looking the other way, north toward Cascade Mountain, from the meadows north of Banff. This was a very photogenic spot.

October 1, 2011

Legends of the Fall

These stars are as much a part of autumn in the northern hemisphere as are the changing colours of leaves and the flying south of geese.

These are the stars of legend, outlining the mythical constellations of Queen Cassiopeia (at top left), her daughter Andromeda (arcing across the bottom half of the image), and the hero Perseus (the stars at lower left) who rescued Andromeda from the ravages of Cetus the sea monster.

These stars are now high in the east in the evening sky, heralding the start of autumn and the return of frosty nights.

There are lots to see with binoculars or a telescope in these constellations. Look around this image and you can pick out several clumps, or clusters, of stars in Perseus and Andromeda. But the most obvious object is the oval-shaped Andromeda Galaxy, visible to the unaided eye from dark rural skies. This is the nearest sizeable galaxy to our Milky Way, and yet its light still takes 2.5 million years to reach us.

I took this shot earlier this week during a run of clear and warm autumn nights, perhaps the last before the chill nights of fall come on. It’s a wide-angle shot with a 35mm lens and Canon 5D MkII camera, tracked for a stack of four 6-minute exposures plus a fifth taken with a soft-focus filter.

July 22, 2011

Stars Over Waterton Lakes II

When I’m doing time-lapse sequences I often run two cameras, one with a wide-angle lens for a frame-filling rectangular view for “normal” HD movies (that’s what’s in the previous blog post), and another camera with a fish-eye lens for a circular format “all-sky” view. These scenes are for projection in full-dome digital planetariums.

This still image is one frame of 470 that I took over four hours on the night of July 20/21, showing the stars and clouds moving in the sky over Waterton Lakes National Park and the stately Prince of Wales Hotel on the bluff across the bay. North is at the bottom of the frame in this shot.

I took this image about 11:30 pm when the sky still had some twilight glow in it and just before the waning Moon was about to rise at right. So the eastern sky has a glow from the impending moonrise. However, the sky is dark enough that the Milky Way shows up running across the sky and down toward the hotel.

You can also see the Big Dipper at left and Cassiopeia at right. The Summer Triangle stars are at top right, in the south. Polaris, the North Star, is dead centre.