This was the scene from my rural backyard on Tuesday night, September 20, with the Milky Way at its best across the sky.
September usually brings the best nights of the year for dark-sky observing and shooting the Milky Way. Nights are clear, dry, and transparent. The Milky Way stretches across the sky from southwest to northeast in the early evening.
Under clear skies on Tuesday the dark lanes and structure of the Milky Way really stood out, both to the eye and to the camera. Image processing for contrast does bring out the dust lanes, including the subtle patches off the main Milky Way band.
The centre of the image contains the three bright stars of the Summer Triangle. They frame the bright Cygnus starclouds and glowing red nebulas that mark the spiral arm that we live in. Above, at top left in the image, is a bluer section of the Milky Way formed by the more distant Perseus spiral arm, the one further out from us in the Galaxy.
I took this shot with the Canon 5D MkII and Canon 15mm lens, for a stack of five 6-minute exposures at f/4 and ISO 800.
— Alan, September 21, 2011 / Image © 2011 Alan Dyer
In this part of the sky the Milky Way takes on a surprising palette of hues. And it’s all due to dust.
The centrepiece of this shot is a bright star cloud in Sagittarius called, well, the Sagittarius Star Cloud! But not the Large one. This is the Small Sagittarius Star Cloud, a.k.a. Messier 24, a mass of stars with a single black eye. The dark spot, called Barnard 92, is a dense and opaque cloud of dust. Stardust — clouds of carbon soot blown out by aging stars — weaves all through this scene, creating the dark canyons winding through the stars. Obscuring dust also dims much of the background stars and discolours most of this part of the Milky Way a yellowish brown. It’s the same effect that dims the setting Sun a deep orange or red, as its light shines through haze and dust in the sky.
But here, the Star Cloud looks bluish and “cleaner.” That part of the Milky Way has less dust in front of it. And yet it is much farther away than the yellow dusty starfields around it. When we look toward the Small Sagittarius Star Cloud we are looking through a dust-free window, allowing us to see unencumbered right past our Galaxy’s nearby Sagittarius-Carina spiral arm to glimpse a dense part of the more distant Norma Arm, an inner spiral arm of our Milky Way Galaxy about 12,000 to 16,000 light years away.
To the lower right of M24 is M23, a rich cluster of stars 2,000 light years away, nearby by galactic standards, and so sits suspended in front of the fainter star background. The pinkish nebula at top is Messier 17, the Swan Nebula.
I took this shot May 2 from Chile, using the Canon 7D and 135 lens, for a stack of six 2-minute exposures.
— Alan, June 7, 2011 / Image © 2011 Alan Dyer
I’m back home in Canada now, after 24 hours of travel from Chile. Despite having to check my carry-on bag filled with cameras and the Mac laptop for the Calama to Santiago domestic flight, all the gear arrived home intact. Now to process the 40+ gigs of images I shot. And properly reprocess some of the images worked on at the dining room table at the lodge, under the bright Chilean sun.
Here’s a shot taken the last night of shooting, of the icon of the southern sky, the Southern Cross, more formally called the constellation of Crux. Next to it, at left, are the dark clouds of the Coal Sack. To the eye, these clouds looks like a uniform dark spot in the sky. But photos, and even binoculars, reveal it as a complex mess of shapes and densities.
What stands out are the colours of the Cross stars. Most are hot blue Type B stars – energetic blue giants. But Gacrux at top is very red – it’s a cool red giant star.
Scattered amid the Cross are Coal Sack are several clumps of stars – open star clusters, such as the Jewel Box Cluster to the left and just below Becrux, the left star of the Cross. On our final night at the Atacama Lodge, we helped out at the lodge in a public stargazing session to a group of tourists from all over the world. I ran a telescope aimed at the Jewel Box and heard lots of ooohs and aaahs at the sight of its multicoloured stars.
This shot is a Mean-combine stack of five 3-minute exposures at f/2.8 with the wonderful Canon L-series 135mm telephoto, and the Canon 5D MkII camera, filter-modified, at ISO 800. The camera was on a Kenko SkyMemo tracking platform, which followed the stars during the 15 minutes worth of exposures.
– Alan, May 9, 2011 / Image © 2011 Alan Dyer
I can’t get enough of this region of sky. I can and do shoot this with every lens I have and with all kinds of framing (horizontally, vertically, or at a rakish angle, like here) and it always looks great.
These are the rich and stunning starfields toward the centre of the Milky Way in Sagittarius (bottom) and Scorpius (at top). Look for the pinkish nebulas dotted along the Milky Way, the bright starclouds, and the dark lanes of interstellar dust. It’s all part of the galactic recycling program that our Milky Way participates in, as stars explode, cast off dust and gas, which then clump into glowing nebulas and form new generations of stars.
I took this shot about 5 a.m. a couple of mornings ago, with this area directly overhead. It’s a stack of six 3-minute exposures with the 35mm lens and Canon 5D MkII camera. I took some shots through a soft focus filter to add the star glows.
– Alan, May 7, 2011 / Image © 2011 Alan Dyer
One of the tenets of my astrophotography “philosophy,” if there can be such a thing (my university degree is in Philosophy after all), is to not spend an enormous amount of time and money chasing after the same images others do, knowing they will likely get far better results than I might achieve, given my location and choice number of clear skies. I don’t live in Arizona, New Mexico or Chile.
Yes, there are certain showpiece objects one is obliged to shoot, to add to the portfolio. But rather than go after many of the usual galaxies and nebulas, I often prefer to shoot wider-field targets that others often bypass.
Simple shots of constellations are often more in demand by publishers than closeups of deep-sky objects, and yet are usually in short supply, as many astrophotographers dismiss them as being “just for beginners.” But good constellation shots still take the right gear, techniques and skies to stand out. Only now am I getting the results I’ve long sought.
With new techniques now in hand, one of my goals is to accumulate a complete portfolio of constellation portraits, though not all of these star patterns stand out as being photogenic. But this one does.
This shot is a recent favourite of mine, of the constellation of Perseus, a rich area of sky. Modern digital cameras show it as the old film cameras never could, laced with reddish dark nebulas of different densities. The Milky Way through this region takes on such a variety of subtle hues achieving correct colour balance is tough.
At top is the loose collection of hot blue stars known as the Perseus Association. At bottom is the most famous tightly bound cluster of stars, the Pleiades. Between is the finger of glowing hydrogen gas called the California Nebula. This photo is an example of how “simple constellation” shots can take on a beauty of their own.
– Alan, February 2011 / Image © 2011 Alan Dyer
An area of sky often neglected but ideal for digital imaging is the region of Milky Way in Taurus and Auriga. Threaded through this area of sky are large lanes of dark interstellar dust, forming cold molecular clouds out of which stars form. This complex is close, only 400 light years away, in our spiral arm of the Galaxy, and so is spread out over a wide area of sky. Only piggybacked cameras with normal and wide-angle lenses capture it. But today’s digital cameras are able to record these kinds of dark nebulae as more than just dark holes in the sky — they have colour, usually shades of reddish-brown.
This is a shot from January 2011 from my home backyard, and takes in all of Taurus, most of Auriga and southern Perseus, with the Pleiades at right and the Hyades below.
— Alan, January 2011 / Image © 2011 Alan Dyer
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