APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Nebula Nova Cygni Turns On
Explanation: Explanation : Old photographs show no evidence of the above nebula. In 1992, a white dwarf star in Cygnus blew off its outer layers in a classical nova explosion : an event called Nova Cygni 1992 . Light flooded the local interstellar neighborhood, illuminated this existing gas cloud , excited the existing hydrogen , and hence caused the red emission. The only gas actually expelled by the nova can be seen as a small red ball just above the photograph's center. Eventually, light from the nova shell will fade, and this nebula will again become invisible!
| Date | December 16, 1996 |
|---|---|
| Credit | Credit: P. Garnavich (CfA), 1.2-m Telescope, Whipple Observatory |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |