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