Crab Nebula tribulations

[lukebl]

Every year I'm drawn to the Crab Nebula, in the vain hope that I might be able to improve on my previous images. This is my latest attempt, using an Omegon RC8 and Atik 428ex. I foolishly thought that getting a longer focal length would mean bigger image on the sensor and thus more detail (my previous captures used a 250mm f/4.8 Newt).

Of course, I'd failed to take into account pixel scale, seeing and the vagaries of the NEQ6 mount. The current combo unbinned gives a pixel scale of about 0.5"/pixel which is way oversampled. And the mount is hardly high-precision. The result is that unbinned images are no sharper than those binned at 2x. Of course, though, binning has the benefit of greater sensitivity.

In fact, this image shows less detail than my previous efforts with the Newtonian. It's still a magical object, though.

Anyway here it is. 20 x 300s exposures each of O-iii and Ha. Green channel synthesised with Noel's Actions in PS.

Edited January 20, 2020 by lukebl

[lukebl]

Here's a slightly less 'cooked' version, which I feel is more pleasing.

[Brian28]

cracking shot !

[lukebl]

Small point of interest. You can make out the Crab pulsar in my image.

One of very few pulsars to be visible optically. It's just 20 kilometres in diameter (20 kilometres!) and rotates 30 times a second.

[simmo39]

A target I always go back to too. Lovely image.