NGC 7635

Alt. Designations: NGC 281
Object Type: emission nebula
Constellation: Cassiopeia
Distance: 9.5 kly
Right Ascension: 00h 52m 53.8s
Declination: +56° 37´ 30"
Visual Magnitude:
Apparent Dimension: 35.0´ X 30.0´
Best Month To View: Oct

NGC 7635, the Bubble Nebula, is an emission nebula in the constellation Cassiopeia located at a distance of approximately 7800 light years. The relatively bright star at about the 5 o'clock position within the prominent bubble is known as BD +602522 and is the source of the bubble shape. The star is known as a Wolf-Rayet star, which is an O-type star that is nearing supernova stage. These stars blow off significant portions of their mass while in this stage. It has an enormous energy output and a powerful stellar wind which is impacting the molecular cloud surrounding the star. This impact is resulting in the bubble shape clearly seen in this image. The bubble is not centered around the Wolf-Rayet star due to differences in the density of the surrounding gaseous material.