By Ian Bradley, Chairperson Eddington Astronomical Society (EAS) Kendal
http://eas-online.org.uk/

Ever since I was young, I wanted to photograph the night sky but, being realistic, for me that wasn’t possible until the advent of digital photography. But now, I really enjoy it. The camera can see so much more than human eyes at night can, colour for one thing, and that possibility excited me.

Having spent many years living in dense urban areas, the relatively low light pollution levels round Kendal allowed me to see so much more of the night sky. Sadly, with increasing population levels and more and cheaper exterior lighting, light pollution is on the rise making it more difficult to see, for example, the Milky Way. For this reason alone, astronomers are concerned and would like to see light pollution reduced. Often the problem is just badly designed or positioned lights, something that is relatively easy to fix.

I started off in the deep end with astrophotography. I became involved in setting up an observatory in a nearby academic institution and a teaching project involving deep sky imaging – we all learnt together. I soon acquired my own telescope and camera, probably the wrong type of telescope, but I learnt a lot from my awful early efforts! And now, I’ve built up a small collection of equipment giving me the ability to photograph widefield starry landscape scenes and the Moon, just a camera on a tripod, planets and now distant galaxies and glowing gas (nebulae) in our galaxy using a telescope, a dedicated astronomy camera and lots of imaging time. After considerable image processing, it is so satisfying to be able to see subtle details in galaxies and nebulae that were impossible to see using my eye at the eyepiece of my telescope.

So, what could you see and maybe photograph? Throughout the autumn, the bright planets of Jupiter and Saturn dominate the southern sky with red Mars rising in the east.  As winter approaches and the nights draw in, the winter constellations start to appear. Magnificent Orion with his obvious belt of three bright stars in a line, bright orange Betelgeuse above and left of the belt and blueish Rigel below and right. Just below the belt is Orion’s sword, the fuzzy area of the Great Orion Nebula, M42, where new stars are being ‘born’. Follow the line of Orion’s Belt up and right and you come to another fuzzy patch, The Pleiades or Seven Sisters. This is a cluster of stars that formed a few million years ago from a nebula similar to M42. See how many stars you can see with your own unaided eye. Binoculars or a small telescope will reveal many more.

Image above, by Ian Bradley, is of a star forming region in the constellation Orion within our galaxy. It has the designation M42 where M is an abbreviation of [Charles] Messier who first recorded fuzzy objects as he was fed up of rediscovering them thinking they were a new comet! Its other name is the Great Orion Nebula. It is visible to the naked eye as a fuzzy patch below the belt of Orion. Credit: Ian Bradley

To see most, get away from street or house lights and let your eyes properly dark adapt. Avoid looking at a bright camera or mobile phone screen – the sensitivity of your eye improves dramatically over 15 minutes or so but this is lost almost instantly! Don’t expect to see the lovely colours in photographs as even dark-adapted eyes just aren’t sensitive enough to detect them – your eye evolved to stop you being eaten by a predator not to star gaze! You’ll see a bit more if you don’t look directly at the object through your binoculars or telescope as the most sensitive part of the eye is at the periphery (avoiding that predator again). To get those colours, you need long exposure photography with the camera tracking to remove the Earth’s rotation. The example of the Great Orion Nebula, below, is the result from several exposures totalling about 20 minutes of exposure using a small telescope, effectively a 430mm telephoto lens.  

Could you photograph the night sky yourself? You can try but beware, this hobby may suck you in! Try using a digital SLR or mirrorless camera using the standard lens. Set the camera in manual mode as you will need to adjust the settings as autofocus and exposure generally will not work. Mount the camera on a tripod, set the aperture as wide open as possible, set the ISO to 1600, manually focus on a bright star, planet or the Moon and then trigger the camera. If you haven’t a remote trigger, use the camera’s self-timer (10seconds is best). Exposures will need to be many seconds, but not too long as the Earth’s rotation will cause the stars to trail. The rough rule of thumb (rule of 500) is 500/ focal length to avoid this. With common cheaper digital cameras and a 50mm lens, the constellation of Orion will fit nicely in the frame and you can easily get 10 second exposures (rule of 500). There is some excellent advice at https://richard529.files.wordpress.com/2020/02/simple-astrophotography-2.pdf

If you’d like to find out more about the fascinating hobby of astronomy and why astronomers are so concerned about light pollution, come along to the Eddington Astronomical Society of Kendal meetings.

Ian Bradley, Chairperson EAS Kendal

http://eas-online.org.uk/