NGC 7635, also called the Bubble Nebula, Sharpless 162, or Caldwell 11,
is a H II region emission nebula in the constellation Cassiopeia.
It lies close to the direction of the open cluster Messier 52 (seen at the upper right)
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 (WIKI)
Imaged with Boren-Simon 10" F/2.8 POWERNEWT Astrograph.
SBIG ST8300M camera with FW5 filterwheel and BAADER HA-LRGB filters.
L = 60 minutes
RGB = 5 minutes each (BIN 2x2)
HA = 21 minutes (BIN 2x2)
Total of 96 minutes.
Imaged from the NEGEV desert in ISRAEL