SH2-240
This is a gigantic nebula in Auriga and Taurus, that I tried to capture last january from my backyard.
Because it is so big, it was a great target for trying a multi-panel mosaic.
It's also extraordinarily faint, so it usually requires very dark skies or very long exposure times to be captured.
Since I don't have the very dark skies, I had to go for the very long exposures but in this case, it's readily apparent that I bit off more than I could chew!
I could only acquire 9 panes before an unfortunate series of events (mostly weather-related) forced me to stop for a few weeks.
Each panel required 9-10 hours of exposure, so this is the result of about 15-20 nights. For the project to be considered "complete" I would have liked to get three more panels at the top, and possibly even three more at the bottom.
Unfortunately this nebula is now too low on the horizon (it has been for a while) for me to "finish it off" this year- so I decided to process it as is.
Processing it has been hard, definitely the most challenging astrophotograph for me thus far. The panes are joined pretty much seamlessly, but because weather conditions changed in the course of the nights I had been working on this, matching the background intensity of the individual frames has been hard. The pixel-peepers will notice that a couple of panes exhibit lower S/N than the others.
at this point,having stared at those pixels for way too long, I'd rather sit back and enjoy the view.
Some info from NASA:
Also cataloged as Sh2-240, it covers nearly 3 degrees or 6 full moons on the sky. That's about 150 light-years at the stellar debris cloud's estimated distance of 3,000 light-years.
This sharp composite includes image data taken through a narrow-band filter to highlight emission from hydrogen atoms tracing the shocked, glowing gas. The supernova remnant has an estimated age of about 40,000 years, meaning light from the massive stellar explosion first reached Earth 40,000 years ago. But the expanding remnant is not the only aftermath. The cosmic catastrophe also left behind a spinning neutron star or pulsar, all that remains of the original star's core
Acquisition details:
Exposures
- 9 x 22 x 30m subs in Ha (5nm)
total exposure time: ~100 hours
Main Camera: QSI 583 WSG
Guide Camera: SXV Lodestar (on OAG)
Mount: Astro-Physics Mach 1
Scope: Explore Scientific 102 ED f/7 (FL: 700mm)
Image Aquisition software MaximDL
Registed, Calibrated and Stacked in MaximDL
Post Processed with PixInsight 1.8 and Photoshop CS6
