The other day I was looking at the
Sloan Digital Sky Survey (SDSS) database table on
photometric classification. I needed to recall which type was a star and which was a galaxy. So I was interested to see the following two listings in this table buried deep in the SDSS information:
Galaxy: An extended object composed of many stars and other matter.
Star: A a self-luminous gaseous celestial body.
I guess I was just surprised at how pedantic it was.
Looks like a brown dwarf is a star by their definition.
ReplyDeleteI guess they don't care why it's self-luminous. That makes life so much simpler.
ReplyDeleteAre planetary nebulae stars? Are globular clusters just many stars? This would make teaching intro astro so much easier.
Guess that's solved. Next problem!
ReplyDelete