Galaxies tend to be much more sensitive to light pollution as compared to other deep sky objects. Living in a city-state with heavy light pollution, imaging galaxies is very challenging indeed. Their low surface brightness, coupled with the fact that they emit light in all wavelengths (therefore rendering astronomical filters useless) makes them difficult targets to acquire. Aside from the Milky Way, I had my first try imaging a galaxy, or rather, three of them, two nights ago. My target is naturally the Great Andromeda Galaxy, M31, as it is the brightest galaxy in the sky. The difficulty in shooting M31 is in bringing out its dark lanes of cold molecular gas. Although the core shines bright, the dim spiral arms make it challenging to process. Also, M31 is huge, not just in physical size, but also in angular size as seen from Earth. It covers the area of six full moons in the sky, but we do not see it in all its glory because of, once again, low surface brightness.
Photographic Information:
Imaging location: Changi, Singapore (Light pollution: Red zone/Outer City)
Date of data acquisition: 29 June 2014
Exposure Details: ~50min, 800mm FL at f/4
Camera: Canon EOS 600D Unmodified
Stacked with DSS, adjustment of curves and colors in Adobe Photoshop CS6.
Shining the light of a trillion suns, the Andromeda galaxy and its two neighbours, M32 and M110 as pictured here, lie 2 million light years away. Although the Andromeda Galaxy is the closest spiral galaxy to the Milky Way, light, the fastest thing in the universe, takes a whopping two million years to arrive into the mirror of my telescope. Looking at the andromeda galaxy, we are looking at the light that originated from the stars long before modern humans have even evolved.
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