Facts

	Spiral	Elliptical	Irregular
Mass	10⁹-10¹²	10⁶-10¹³	10⁸-10¹¹
Luminosity	10⁸-10¹¹	10⁶-10¹¹	10⁸-10¹¹
Diameter	10-100	2-400	2-6
Stars	PopII-halo,bulge PopI-disk	Pop II	Pop I & II mixed
Gas & Dust	In the disk	Very little	In abundance
Location	Preferentially in low galaxy density regions	Large ellipticals- primarily in rich clusters Dwarfs-omnipresent	Preferentially in low galaxy density regions

The masses and luminosities in this table are in units of the mass and luminosity of the sun. One solar mass is 2 x 10³⁰ kg and one solar luminosity is 3.9 x 10²⁶ watts. The diameter is in thousands of light-years.

Other facts

77% of observed galaxies are spirals
20% of observed galaxies are elliptical
3% of observed galaxies are irregular

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These pages designed by Erin McNally (CU'00)... Last modified 18Apr00