It’s a relatively rare event to be able to photograph a good dark sky over the mountains. There needs to be a new moon, a high-pressure weather system keeping the skies clear, and a free night without an early morning the next day. So when it all comes together, it’s time to get out there!
The plan was to shoot the northern sky above Mt. Kidd in Kananaskis country, Alberta. About 100km from Calgary, it’s a peak that I have some history with, having nearly lost two of my best friends in a spring avalanche as we descended the normal scrambling route in 2005. But the mountain has some stunning geologic folds on the south side that the winter snow highlights nicely, and tonight should be a much more peaceful time.
One of the issues with winter is that most of the mountain parking lots are closed and unploughed, thick with snow, so I have to park the car and setup the camera on the side of the highway. Generally not the safest thing to do, but this highway is pretty empty late on a Wednesday night, and in four hours I only had about 6 cars drive by, and one stopped to say that he was out photographing the sky as well.
The best view of Mt. Kidd from the highway is looking NE, which in early evening winters positions the northern Milky high in the sky. The northern Milky Way is the view through our galaxy, looking out away from the galactic center.
Before scrolling down too far, a properly adjusted monitor is key to viewing these night photographs accurately. Adjusting the Contrast and Brightness of your monitor should allow you just barely distinguish between the different shades of gray on the following strip.
OK, now that you’ve fixed your monitor, carry on…
Galaxies over Mt. Kidd
Click to zoom into the high-resolution (50 megapixel) mosaic. All frames are 2-minute exposures, 50mm lens at f4.0, ISO 1600.
Perseus, Cassiopeia and Cepheus
The galactic plane of our Milky Way galaxy passes through the sky between Perseus and Cepheus and is rich with star clusters and nebula. Because the stars in a cluster all formed from a collapsing cloud of gas at roughly the same time, they are active areas of research into stellar evolution and life cycles.
Visible to the naked eye are twin star clusters known as the Double Cluster in Perseus. Each cluster contains over 300 young, hot, blue supergiant stars, which do not live for long and end their brief lives as supernovas that form and scatter heavy elements throughout the galaxy. And this is where the atoms that make up your body come from! You are literally made up from the ashes of long-dead stars, a pretty mind-boggling concept.
The first records of these two clusters were in ancient China during Hsia Dynasty (2858-2146 BC) and also by Hipparcus is 130 BC. In Chinese astronomy legend, the twin clusters represent Hsi and Ho, two astronomers who failed to predict a total solar eclipse and were beheaded as a result. High stakes astronomy! The clusters are roughly 7000 light-years away from us, and because of their similar age are thought to have formed from the same gas cloud.
Like many of our constellations, Perseus was named after a hero of Greek mythology. Algol is a star on the right “leg” of the constellation Perseus, and is the first variable star discovered, recorded in 1667. Stars are variable when their brightness changes periodically, and the variability in Algol is caused by a very close-orbiting companion star eclipsing the brighter main star every 69 hours. That’s a very quick trip around a star, considering that Earth’s orbit takes 365 days, and Mercury, the closest planet to our Sun, takes 88 days. Known in antiquity as the Devil Star, it is suspected that this variability had been noticed well before the 17th century.
The red cloud at the left side of Perseus is the California Nebula, NGC 1499, a giant galactic cloud, over 100 light-years (!) long, comprised mostly of hydrogen and glowing red because the gas is ionized by the light of a nearby, enormous hot blue star.
Messier 34 is an open star cluster about 1500 light-years away. Messier 76 is one of the dimmest of the Messier objects and is the exploded remnants of a star at the end of it’s life, barely visible in this image.
To the right (north) of Perseus and its Double Cluster lies the constellation of Cassiopeia, easily recognized as a large “W” in the sky, visible pretty much all year round. In Cassiopeia are almost a dozen star clusters, but only two of them (M52 and M103) were small and fuzzy enough to be able to be confused with a comet and thus making it to Messier’s 18th century list.
Just below M52 is the Bubble Nebula, NGC 7635, a massive (10 light-years in diameter!) bubble blown into the surrounding gas by a very bright (100,000s times our Sun) and hot star. Between Cassiopeia and Cepheus is the large star-forming region NGC 7822, visible here as glowing red gas (ionized hydrogen) surrounding a central star. This immense gas cloud is in the process of forming stars and planetary systems, and it’s gas is being eroded into massive pillars, light-years long, by the stellar wind and radiation of hot, heavy and bright young stars within it, resulting in a spectacular stellar landscape.
Andromeda Galaxy, M31
This part of the sky hosts perhaps the most impressive deep-sky object, our nearest large galactic neighbor, the Andromeda galaxy, which is roughly 2.5 million light-years away. Under very dark skies, the Andromeda galaxy is visible to the naked eye as a faint, fuzzy patch, and was first recorded in a star chart by the Persian astronomer Abd al-Rahman al-Sufi in 964 AD. It was observed by subsequent astronomers, and included in the Messier catalog in 1764 as Messier 31.
The object was the center of the great astronomical debate in the 1920s about whether this “nebula” was within or outside of our own galaxy. The debate was conclusively resolved in 1925 by Edwin Hubble, who showed that this object is in fact an entirely separate galaxy, far outside of our own, a revelation which vastly increased the size of the universe and completely changed our understanding of our position within it. Science blogs Messier Monday has an excellent article on this debate and the revolutionary change in perspective it provided.
Galaxies come in groups, and the Andromeda galaxy is the nearest, and largest, member of our Local Group of Galaxies. It has two much smaller galaxies orbiting around it, both of which were also cataloged by Messier as possible comets, M32 and M110. There are two more members of our Local Group of galaxies captured (barely) in this image, NGC 185 and NGC 147, both of which are considered satellite galaxies of Andromeda.
The light pollution from Calgary spreads far beyond the 100km to Kananaskis country, and in long exposures overwhelms the image.
To take these photos I used an in-camera filter from Astronomik that removes the yellow-green center portion of the visible spectrum, which is the region where mercury-vapor street lights emit light. There is natural sky-glow in the atmosphere which is also partially removed by this filter.
These unprocessed images show a dramatic difference between the raw capture with and without the filter, but after processing in Adobe Lightroom, the different is less obvious. The final image is improved, especially the visibility of the subtle red nebulosity sweeping through the upper and left side of Orion.
The filter is excellent, and results in higher contrast images with a deeper black and more vivid stars and deep-sky objects. However, like any filter it results in a different coloration of the final image, in this case a blue/cyan colour cast, that needs to be fixed during processing.
These two images of Orion were taken with the Canon 100mm f2.0 lens at f3.5, 100 seconds, ISO 800 with a Canon 6D. Processing of each image was different, due to the different colour balance and image intensity with and without the filter.
Finding Clear Dark Skies
As human population grows and we relentlessly spread into every remote nook and cranny of our planet, it becomes ever more difficult to find dark skies that are free from the haze of artificial lights. David Lorenz at the University of Wisconsin has compiled a global map and has made it available as an excellent Google Map overlay of light pollution.
Of course, the other element that is crucial for observing the night sky is good weather. For detailed forecasts of local sky conditions, including cloud cover and atmospheric transparency, see the excellent Clear Dark Sky website.
The universe is nearly infinite, challenging to explore and stunning beautiful. To clear skies and wild places!
Darren Foltinek, © 2014