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. The ‘bubble’ is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). 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.
Equipment and processing
Telescope: Orion 8 inch F5
Mount: Orion Atlas
Camera: ST 8300M
Filters: Baader Ha,SII,OIII 7nm
Capture software: Maxim
Exposures: Ha: bin1 154x600 OIII: bin2 72x600 SII: bin 78x600