Crab Nebula – Need Bigger Scope

After my series of open star clusters, I decided to try my luck with the neighboring Crab Nebula (Messier 1).  A single 30s exposure show some signal, but barely above the background light pollution.

Very faint M1, just above light pollution levels

Very faint M1, just above light pollution levels

OK, lets see what the wonders of digital stacking and post-processing can do…

After stacking 28 frames, and various histogram and level stretching, I was able to get the nebula to stand out.  That’s quite an improvement from the single frame from above.

Crab Nebula - Messier 1 - Benoit Guertin

Crab Nebula – Messier 1 – Benoit Guertin

I couldn’t get any color out of it, but I believe the color images of the Crab Nebula that you often see are compositions from narrow band filters, and are “scientific colors”.

Conclusions, need to gather more light and image at a longer focal length.  Even if I increase my exposure time, as the object is small I won’t be able to get much detail out of it.  I could add a barlow to double the focal length, but would also need to further increase my exposure time.  If I try this again, I’d need a 2x barlow and at least 2 minutes exposition, and have everything autoguided.  Not there yet… Best reserved for larger and more powerful telescopes.

Skywatcher 80ED
Canon XTi (400D) ISO 800
28 x 30sec (stacked with IRIS and post-processed in GIMP)

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