I’ve been chasing the Moon this week. I caught up with it last Thursday night, August 4, in Banff, with the waxing crescent Moon low in the southwest at dusk.
The location is the upper Vermilion Lake just outside the Banff townsite. The golden reflection of the low Moon on the water, the slope of the mountainside and its reflection, the dock and steps, and the tail lights from a vehicle on Highway 1 just up the hill (I decided to leave them in!) make for what I think is an interesting composition of converging lines.
I got set up and in position just in time to catch the scene at the magic hour of twilight, when the sky is dark enough the show deep colours and the Moon’s entire disk shows up, but before the sky gets too dark and the Moon too bright to make an interesting scene.
Even so, the contrast in such a scene is still very high. So to capture it more as your eye would have seen it I used a stack of five exposures, taken in rapid succession, each 2/3rds of an f-stop apart. I then merged the frames with Photoshop’s High Dynamic Range routine to create a scene that brings out detail in the foreground without overexposing the Moon and sky.
A technical method to capture a simple scene of serenity in the mountains.
— Alan, August 7, 2011 / Image © 2011 Alan Dyer
As all the other sunset photographers were packing up for the night, I was just getting started. This is the scene last night, with the waxing Moon hanging over the moonscape of Dinosaur Provincial Park in southern Alberta.
I took this in deep twilight, when the sky is tinted with subtle colours complementing the earth tones of the landscape below.
Dinosaur Park is the world’s best repository of late Cretaceous fossils, being unearthed as the terrain made of ancient volcanic ash erodes away with every rainstorm. Though the formations date from the Cretaceous some 70 million years ago when this area of Alberta was a bayou-like swamp, the badlands landscape we see today was created at the end of the last ice age when glacial floods poured over the landscape, carving the channels occupied by rivers today, like the Red Deer River that flows through Dinosaur Park.
It’s a favourite spot of mine, just an hour east of where I live, to shoot sunsets and moonrises, and twilight landscapes like this one.
— Alan, August 7, 2011 / Image © 2011 Alan Dyer
Here is nearly two hours of auroral dancing compressed into 25 seconds.
This was the “all-sky” aurora of August 5/6, 2011, widely seen over North America but perhaps (from early reports) best from the western half, especially Canada, favoured for Northern Lights due to our latitude.
I shot this with the 8mm fish-eye lens and the Canon 5D MkII. The movie consists of 255 frames, each 24 to 30 seconds in exposure duration, taken one second apart. ISO speed was 1600 and aperture f/3.5. The playback frame rate is 10 fps.
This display was quite chaotic, without the graceful rippling curtains present in many displays, but rather huge patches of sky turning off and on. This is typical of an aurora in the declining part of the storm — it had already been raging for several hours by the time it got dark here in Alberta.
Nor was the display very bright, so the longer exposures needed to record it well further blur any fine motion. Nevertheless, you get a good idea of the intense activity this aurora displayed. The magnetosphere was jumping last night!
— Alan, August 6, 2011 / Movie © 2011 Alan Dyer
It’s been quite a while since I’ve seen a display of Northern Lights as good as this one. But with the Sun picking up in activity from a record lull in the last few years, great all-sky displays like this might become more frequent.
The last time I saw aurora cover most of the sky like it did last night (August 5) was back in the days of shooting film. So this was the first chance I had to shoot an all-sky aurora with digital cameras. This is with the Canon 7D and the ultra-wide 10-22mm zoom. I also shot with the fish-eye 8mm, and an “all-sky” movie of those frames will be in the next posting.
This display was widely seen and predicted, as solar monitoring satellites had observed major flares on the Sun earlier in the week and tracked the resulting “coronal mass ejections” across the solar system. We knew they were aimed at Earth and would hit August 5. In this case, the resulting geomagnetic storm raged for long enough that people across a wide swath of longitudes from Europe to North America were able to see the display during their local night, August 5/6. Even people in the northern U.S. had a good look.
While the display was certainly active and extensive it never did get really bright. So this one still falls short of the “10 out 10” scale for spectacle. Nevertheless, as digital cameras can do so well, the images picked up the greens from glowing oxygen with remarkable intensity. More interesting are the purples, seen toward the beginning of the night but then they faded away. The purple tints come from the tops of the towering curtains of aurora which often glow red from nitrogen molecules at very high altitudes being charged up and excited. But the tops of the curtains can also be lit by sunlight. The blue from the sunlight and the red from the aurora itself mix to produce a purple tint. Only the camera picked this up.
— Alan, August 6, 2011 / Image © 2011 Alan Dyer
This was the scene Monday night and into Tuesday morning, August 1/2, as a relatively new comet to our skies passed a bright globular cluster known as M15 in Pegasus. The comet is Comet Garradd, or more formally C/2009 P1. Here it glows with the characteristic cyan tint of many comets and sports a stubby fan-shaped tail.
As comets move across the sky they often appear near prominent deep-sky objects for a night or two before moving on. Comet Garradd has a number of such encounters coming up: with the globular cluster M71 on August 26, and then near the neat Coathanger cluster September 1 through 3.
Comet Garradd can be spotted now from a dark site in big astronomy binoculars and is a fine sight in a telescope. However, it is well below the threshold of naked-eye brightness and is expected to remain so as it moves high across the summer sky from east to west and then into the western evening sky in late autumn. It is certainly well-placed for viewing, but only comet aficionados are likely to pay much attention to it. Plus astrophotographers taking advantage of photo ops like this one.
— Alan, August 2, 2011 / Image © 2011 Alan Dyer
Look straight up on a summer night in the northern hemisphere and you are looking into this region of sky. This is the centre — the heart — of Cygnus the swan, marked here by the bright star called Sadr, or Gamma Cygni.
While the star is easily visible to the unaided eye, the glowing clouds of gas surrounding it are not. Only long exposure images reveal the amazing swirls of nebulosity in the middle of Cygnus.
The main cloud at left, split by a dark lane of dust, is catalogued as IC 1318. The little crescent-shaped nebula at right is NGC 6888, or more appropriately, the Crescent Nebula. It formed when a hot giant star blew off its outer layers, to add to the general melee of hydrogen and other elements. But note the little blue reflection nebulas at top left. Oddly out of place!
New stars are forming in this region, located about 1500 light years away down the Cygnus arm that we live in, in the Milky Way Galaxy.
This field can be framed nicely by binoculars or a low-power telescope, but only the brightest bits of this nebulosity will show up in the eyepiece as grey ghosts, and then only with the aid of a specialized nebula filter.
I took this shot on Saturday night, July 30, 2011 with the Borg 77mm f/4 astrograph lens and Canon 5D MkII camera. Other stats are similar to the previous blog post. It’s certainly my best shot of this area of sky.
— Alan, August 1, 2011 / Image © 2011 Alan Dyer