NGC 7635, also known as the Bubble Nebula, is 10 light-years wide and is expanding at 4 million miles per hour (7 million km/h). The large star seen in the upper right of the bubble is believed to be about 10 times larger than our sun and the energetic source of expansion for the bubble. It is 7,100 light-years away in the constellation Cassiopeia.
(NASA APOD (Astronomy Picture of the Day) on January 24, 2009)

Image Aquisition information:

Date: October, 2008
Location: Starlodge Observatory, Ione, CA
Camera: STL 11000
Telescope: Planewave CDK 12.5
HA:R:G:B 200:60:60:60