A Truly Amazing Sky — A New Year’s Gift


Timor Cottage Panorama #3

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

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

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

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

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

Zooming into Canis Major – #3


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

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

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

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

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

Zooming into Canis Major – #2


IC 2177 Seagull Nebula Complex

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

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

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

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

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

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

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

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

 

Zooming into Canis Major – #1


M50 - M46/M47 Area Bino Field

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

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

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

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

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

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

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

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

Canis Major and the Dog Star


Canis Major from Australia (50mm 5DII)

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

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

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

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

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

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

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

 

The Christmas Tree Cluster


NGC 2264 Christmas Tree Cluster & Cone Nebula

 

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

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

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

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

 

A Cosmic Wreath in the Sky


NGC 2237 Rosette Nebula

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

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

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

Happy holidays to all!

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