Coma, deliberately...

[ollypenrice]

One of my favourite binocular objects, the Coma Cluster. I once got a nice slide of this and for simple star clusters I don't think CCD is as good. Anyway here it is, a stocking filler after my main target had set. Conon EF200L lens and Atik 4000 OSC CCD.

You can see a few little Coma-Virgo cluster galaxies in there as well. The very tip of the popular NGC4565 is just peeping in on the left hand edge. Bother, should have got that in!

Olly

[jgs001]

Lovely Olly, is this also known as Mel111 ?

[ollypenrice]

Lovely Olly, is this also known as Mel111 ?

Yes, though I didn't know that till just looking it up!

Olly

[jgs001]

... so many different names

[andrew s]

Wherefore cometh the spikes on the bright stars Olly?

[ollypenrice]

Wherefore cometh the spikes on the bright stars Olly?

From the diaphragm of the camera lens, which was stopped down to f3.5. When you look down a stopped down lens the diaphragm is formed in segments so is not round. This generates the diffraction effects. I have it in mind to try the lens wide open, which might be possible since my chip is smaller than that for which it is designed. Another way to avoid them might be to make a front aperture mask and leave the lens wide open internally. I do mean to give this a try but I suspect it is a bit optimistic.

Olly