SH2-157, the Lobster Claw Nebula, is an emission nebula located about 11,000 light-years away in the constellation of Cassiopeia.
According to SHO palette, red/orange and predominantly yellow regions of the nebula evinced a very large H II region while the blue-colored are predominately regions featured by the emission of light from molecular oxygen.
On the top NGC 7635 – the Bubble Nebula, and on the middle the star cluster NGC 7510.
Astrobin:
