Mask_Neo 2010-12-01 02:27:26




Galaxies are the largest
structures in the universe. Each
contain hundreds of millions of
stars, and there are billions of
galaxies in the visible universe. In
fact, in one three degree section
of the sky known as Coma
Berenices, we can see more than
1000 galaxies.

The Facts

1) Main Types of Galaxies: 3;
>Spiral
>Elliptical
>Irregular (Ellipticals and Irregulars exist in both normal
and 'dwarf' sizes)

2) Number of Galaxies Visible:
100 billion

3) Most Abundant Type of
Galaxy: Dwarf Ellipticals

4) Distribution of Normal Size
Galaxies in Hubble
Classification: Spiral-75%;
Elliptical-20%; Irregular-5%
(Edwin Hubble's data was
skewed because spirals are
generally brighter than any other
galaxies, and he found more of
them. Dwarfs are dim and were
not found until bigger telescopes
were built.)

5) Spiral Galaxy Nearest Our
Milky Way Galaxy: Andromeda -
2.6 million light years away. (The
Magellanic Clouds - dwarf
irregulars--are only an average
200,000 light years away, but
they are more giant star clusters
than galaxies.)

6) Distance of Visible Galaxies
Fatherest From Us: Appx. 14
billion light years.

7) Size of Typical Galaxy: 3,260
light years to 326,000 light years
across.

8) Number of Stars in Average
Galaxy: 40 billion

9) Number of Stars in Typical
Large Galaxy (such as our Milky
Way): 200 billion to 400 billion.

10) Number of Galaxies in Local
Group: Appx: 40 (there may be
dwarfs so dim we can't see
them).

11) Largest Galaxy in Local
Group: Andromeda

12) Smallest Galaxy in Local
Group: Leo T, a dwarf irregular
600 light years across

13) Number of Galaxies in
Average Galactic Group: <50

14) Fewest Number of Galaxies
in Known Group: 4