Right Angle Moon


Saturday night was a fine evening for witnessing the geometry of the night sky.

This is sunset on the evening of the autumnal equinox, September 22, 2012, with a first quarter Moon in the sky. The image illustrates the geometry of the quarter Moon’s position, which is always 90° away from the Sun, a quarter of the way around its orbit in its monthly cycle.

In this case, because the Sun (at right) was on the equinox position on the ecliptic, it was setting due west this night (something it does only on the dates of the fall or spring equinox). This put the quarter Moon (at left) 90° away, due south at sunset.

Draw a line from the Moon to your eye (the camera) and then back out to the Sun and it forms a 90° right angle. This geometry holds true for any quarter Moon, but being equinox the Sun and Moon were nicely aligned due west and south, making their right angle arrangement more obvious.

I took this shot from the grounds of the Rothney Astrophysical Observatory on the occasion of their monthly Open House.

– Alan, September 23, 2012 / © 2012 Alan Dyer

 

Star Death Site


This is the graveyard of where a star died at the dawn of civilization.

The Veil Nebula, made of several fragments, is the remains of a star that exploded as a supernova some 5000 to 8000 years ago. With a telescope you can see this deep sky wonder high overhead these nights, in Cygnus the swan. A decent sized telescope, say 15 to 25cm diameter, can show a lot of the detail recorded here, but only in black-and-white. It takes a photo to pick up the magentas, from glowing hydrogen, and cyans, from oxygen being excited into shining by the shockwave created as the expanding cloud ploughs into the surrounding interstellar gas.

The whole complex is called the Veil Nebula but the segment at right passing through the star 52 Cygni is called the Witch’s Broom Nebula.

I shot this from home a couple of nights ago during a continuing run of typically fine fall weather, which usually brings the best nights of the year for astronomy. For this shot I used a new Lunt 80mm apochromatic refractor on loan for testing. It works very well! This is a stack of five 15-minute exposures.

– Alan, September 22, 2012 / © 2012 Alan Dyer

Star Party Sunset in the Badlands


A hundred or so stargazers were treated to a beautiful sunset in the badlands of the Red Deer River valley on Saturday night.

This was the setting for the annual Alberta Star Party, at a campground north of Drumheller, Alberta, amid the late Cretaceous sediments of the badlands. This is big sky country.

Earlier in the week the night sky was clear and inviting. But this night the clouds served only to provide a fine sunset. They failed to disappear after nightfall. However, on a such a night, a good time is still had by all as everyone enjoys the company of fellow stargazers during the last of the fine weather before star party season ends for another year.

I took this 360° panorama with a handheld camera, and stitched the segments in Adobe Photoshop CS6.

– Alan, September 16, 2012 / © 2012 Alan Dyer

 

Star Trail Reflections


The stars of the southern sky arc over the peaks of the Lake Louise Range in this half-hour’s worth of exposures.

For this shot I took 35 frames from a 200-frame time-lapse movie and stacked them to create star trails moving over about 25 minutes time when the sky was dark and moonless. I also layered in the moonlit landscape from a frame taken at the very end of the time-lapse sequence when the Moon has risen and was lighting the mountains and trees. So this scene is a bit of a Photoshop fake, but only so far as to merge exposures taken a couple of hours apart from the same fixed camera to combine the sky and stars from when the Moon was not in the sky with the ground from when it was, so the ground isn’t too dark and featureless.

What most people find surprising about star trail shots is the range of colours displayed. Some of the magenta trails come from a little chromatic aberration in the lens. But nevertheless, stars do exhibit lots of colours, but usually only in time exposures like this. As a bonus one frame captures either a meteor or an Iridium satellite flare at right above Mount Victoria.

I took the images for this scene on Friday, September 7, on a shoot at Herbert Lake in Banff.

– Alan, September 14, 2012 / © 2012 Alan Dyer

 

September Dawn


Here was the scene on September 12, with Venus and the Moon in conjunction in the dawn sky.

Orion stands above the trees, and at top is Jupiter amid the stars of Taurus. The star Sirius is just rising below Orion. And both the Moon, here overexposed of necessity, and Venus shine together below the clump of stars called the Beehive star cluster in Cancer. This was quite a celestial panorama in the morning twilight.

This is a stack of two 2-minute exposures taken just as dawn’s light was breaking, so I get the Milky Way and even a touch of Zodiacal Light in the scene, as well as the colours of twilight. Pity I can’t avoid the lens flares!

– Alan, September 12, 2012 / © 2012 Alan Dyer

 

Milky Way Amid the Trees


This is the classic summer campsite shot, looking up through the trees to the Milky Way.

I shot this Saturday night from a favourite viewpoint in Banff at Saskatchewan River Crossing. The night proved to be less than the perfectly clear I had hoped for, so I settled for Plan B and shots looking up to a nearby nightscape scene, rather than out across a landscape and into horizon clouds. Some drifting clouds in this shot blur the stars.

This is an example of the type of simple nightscape anyone can do with a camera on a tripod. There’s no tracking going on here, just a short 70-second exposure, enough to pick up the Milky Way. The little trailing of the stars that results isn’t objectionable. I could have shortened the exposure and decreased the trailing but only by going to a higher ISO speed like ISO 3200 which, with the Canon 7D camera, is pushing it too much for noise in a shot like this.

Better still would have been to place the camera on a tracking platform. expose longer at an even slower, less noisy ISO speed, and then let the trees blur from the camera’s motion as it followed the stars. It would have simply looked like a windy night.

Or, it’s possible to combine tracked and untracked exposures, one for the sky and one for the ground, using Photoshop magic.

But I did neither here. This is an unadulterated image of the summer sky shining through trees.

– Alan, September 11, 2012 / © 2012 Alan Dyer

 

Milky Way Over Calm Water


This is a scene I’ve been after for some time – the Milky Way and stars reflected in calm water.

In Friday night I was at a small lake, a pond really, at the south end of the Icefields Parkway in Banff. Herbert Lake is small enough it is usually calm and reflective. Friday night was as clear and calm as you could hope for. This image is from the beginning of the night with some blue twilight still illuminating the sky, but no moonlight. The waning Moon did not rise until 11:30 pm. I shot this prior to starting a 3-hour time-lapse from the same position on the lakeshore.

The scene is looking south toward glacier-clad Mount Temple and Mount Fairview near Lake Louise.

This is a single exposure with the Canon 5D MkII and 16-35mm lens.

– Alan, September 9, 2012 / © 2012 Alan Dyer