How many stars do dwarf galaxies have?

[seriously disabled]

How many stars do dwarf galaxies have? Also how many stars does an average or regular galaxy have?

[Martin]

How many stars do dwarf galaxies have? Also how many stars does an average or regular galaxy have?

 

http://en.wikipedia.org/wiki/Dwarf_galaxy

 

"A dwarf galaxy is a small galaxy composed of up to several billion stars, a small number compared to our own Milky Way's 200-400 billion stars. The Large Magellanic Cloud, containing over 30 billion stars, is sometimes classified as a dwarf galaxy while others consider it a full-fledged galaxy going around the Milky Way galaxy."

 

I don't want to suggest that the Wikpee is an authority, but this does roughly correspond to what you might learn in a general astro course. We were told that Milky has about 400 billion. That was some time back. I don't know what the best estimate is now.

 

A dwarf has just a few billion, like under 10 billion. Apparently the classification is fuzzy.

Edited December 31, 2008 by Martin

[seriously disabled]

http://en.wikipedia.org/wiki/Dwarf_galaxy

 

I don't want to suggest that the Wikpee is an authority, but this does roughly correspond to what you might learn in a general astro course. We were told that Milky has about 400 billion. That was some time back. I don't know what the best estimate is now.

 

A dwarf has just a few billion, like under 10 billion. Apparently the classification is fuzzy.

 

Hi Martin. Thanks for the reply.

 

The problem is that wikipedia later says in a different article that "typical galaxies range from dwarfs with as few as ten million (10^7) stars up to giants with one trillion (10^12) stars, all orbiting a common center of mass".

 

http://en.wikipedia.org/wiki/Galaxy

 

So can a dwarf galaxy contain only 10 million stars or is this number too small?

[Martin]

 

The problem is that wikipedia later says in a different article that "typical galaxies range from dwarfs with as few as ten million (10^7) stars up to giants with one trillion (10^12) stars, all orbiting a common center of mass".

 

http://en.wikipedia.org/wiki/Galaxy

 

So can a dwarf galaxy contain only 10 million stars or is this number too small?

 

I think Wikipedia is consistent. The two articles just give approximate upper and lower limits on a conventional category.

One says the range goes as high as few billion. ( http://en.wikipedia.org/wiki/Dwarf_galaxy )

The other says it goes as low as ten million. ( http://en.wikipedia.org/wiki/Galaxy )

 

So it looks like the range for this particular phrase, for these words "dwarf galaxy", is

10^7 up to 10^10 or thereabouts.

 

I don't think we are discussing nature here as much as we are discussing human language. Nature can have a great range of sizes, even including what are called "globular clusters" with less than a million stars. I think it is mostly just a matter of custom and convention how we divide it into segments and what we call some particular segment.

[timetes]

why would they call it a dwarf galaxy? Does that mean there are no future exploding stars possible in that galaxy?

[timetes]

I learn something new every day......I watched the science channel last nite and always thought that the universe was moving away and spreading out, but learned that the our galaxy the milkyway is moving toward andramida galaxy. Interesting stuff:)

[NowThatWeKnow]

I learn something new every day......I watched the science channel last nite and always thought that the universe was moving away and spreading out, but learned that the our galaxy the milkyway is moving toward andramida galaxy. Interesting stuff:)

 

It seems that local gravitational forces causes many galaxies, and even galaxy clusters, to collide. However, after a certain distance away, the expansion of space makes sure all galaxies are moving away form us.