Andromeda versus Milky Way

[Vanda]

I just saw a show on foxtel "cosmic collisions" where it was stated Andromeda was more massive than the Milky Way. However, I thought the Milky Way was more massive but of smaller dimensions?

[AlexN]

I think on a TV show they will measure how massive a galaxy is based purely on its physical size, not its total mass..

[orestis]

hi,
i've heard that the andromeda galaxy is bigger in terms of size/distance from one side of the galaxy to the other.But that the milky way is more dense in total mass.milky way spans 100,000 light years across.not sure for andromeda.

hope this helps
orestis:thumbsup:

[Robh]

The diameter of the Milky Way Galaxy is estimated at 100000 light years. It contains perhaps 200 to 400 billion stars.
The diameter of the Andromeda Galaxy (M31) has been estimated at 140000 light years (3.18 degrees of sky). This is calculated from a distance measurement of roughly 2.54 million light years. M31 may have as many as 1 trillion stars.
However, recent findings indicate the Milky Way has more dark matter. A 2009 study indicates the masses of the two galaxies may in fact be roughly equal.
(Data sourced from Wikipedia).

Regards, Rob