Number 173 in the Sharpless-2 catalog of hydrogen emission targets in the Northern Hemisphere, aka the Phantom of The Opera Mask Nebula. This is in the constellation Cassiopeia, some 8800 light years away.
This is quite a faint nebula, and took two full nights of imaging. There are no oxygen or sulfur data here, the nebulosity is all hydrogen. I did some color tweaking to simulate the hydrogen-beta and hydrogen-gamma emission lines in addition to the hydrogen-alpha that I actually recorded.
Nine and a half hours of Ha exposure plus a couple hours of RGB for the stars.
Number 173 in the Sharpless-2 catalog of hydrogen emission targets in the Northern Hemisphere, aka the Phantom of The Opera Mask Nebula. This is in the constellation Cassiopeia, some 8800 light years away.
This is quite a faint nebula, and took two full nights of imaging. There are no oxygen or sulfur data here, the nebulosity is all hydrogen. I did some color tweaking to simulate the hydrogen-beta and hydrogen-gamma emission lines in addition to the hydrogen-alpha that I actually recorded.
Nine and a half hours of Ha exposure plus a couple hours of RGB for the stars.
