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.
January 3, 1997
Explanation: Wolf-Rayet stars can blow bubbles. These
unusual stars are much hotter and more luminous than our Sun.
All extremely massive stars will eventually evolve though a Wolf-Rayet
phase. Approximately 200
are known in our Milky Way Galaxy.
because they continually eject their outer atmosphere as a stellar
wind. This outgoing wind of particles typically carries away
more than the mass of our Earth each
year! The wind is caused by atmospheric particles absorbing outgoing starlight,
although many details of this process are unknown. The Wolf-Rayet
is the brightest star in the above picture
and is in the centre of the large bubble in the nebula known as NGC 2359.
Authors & editors:
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
&: Michigan Tech. U.