HAPPY BIRTHDAY, HUBBLE!
The cosmic telescope Hubble celebrates its 26th birthday!To commemorate this event the telescope sent a photograph of an unusual nebula NGC 7635 in Cassiopeia constellation. It is a 'bubble' of interstellar gas created by radiation fluxes from O-class 40 Solar mass star SAO 20575. The star is surrounded by dense gas clouds which slightly constrain the expansion of this ‘bubble’, the diameter of which is considered to be 10 light years. The distance to the nebula is about 8 thousand light years. http://www.spacetelescope.org/news/heic1608/