Thursday, 7 April 2011

So faint… it isn’t actually there.

George Abell spotted his 17th splodge on the deep sky survey in this location and classified it as a faint planetary nebula (a fluorescent stellar corpse) of 18.5 magnitude. This is in the realms of extremely dim, 1/40th as bright as Pluto, and Pluto is 1/2500th as bright as the faintest star you can see with the naked eye, and that is dimmed further by being smeared over a small area. The red smear across the top of the photo represents a lesson in how to be careful when taking space photos. It must have been caused by the red computer mouse light from across the dome! When you get into the realms of extremely dim everything’s too light. Phones are out of the question and monitors must certainly be off. Plus there’s an annoying LED that comes on my new camera while it’s exposing. How dumb. Notwithstanding the distracting straight line upper right of centre, I have marked the location and size of the nebula on the photo, where I can sort of half-imagine a very faint reddish ring. Well this was later classed as not a nebula at all it was a plate flaw, which was obvious and just to the left of my marked area. Is it a circular collection of stars below the detection limit of the instrument? Or is it just that the background ‘static’ noise in my camera has fortuitously created a false nebula in combination with a computer mouse?

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