NGC 7635, also called the Bubble Nebula, Sharpless 162, or Caldwell 11, is a H II region emission nebula in the constellation Cassiopeia.
The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star.
The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow.
It was discovered in 1787 by William Herschel.
The star SAO 20575 or BD+602522 is thought to have a mass of 10-40 Solar masses.

Hubble color mapped S2-Ha-O3 as RGB

HA -7 HRS (BIN1)
S2 O3 - 2 Hrs each (Bin 2)


Total of 11 Hrs.

12" Classic Meade LX200 with F7.5 Starizona corrector.

Mount - ASA DDM 60 PRO
NO GUIDING :)
Camera - SBIG ST8300M with BAADER filters.
Imaged from my home observatory in Gan-Yavne, Israel