Explanation:
Why are these stars moving so fast?
Shown above is a time-lapse movie in
infrared light detailing how stars in the central light-year of
our Galaxy
have moved over the past eight years.
The yellow mark at the image center represents the location of a peculiar
radio source named
Sgr A*.
If these fast stars are held to the
Galactic Center by gravity,
then the central object exerting this
gravity must be both compact and massive.
Analysis of the
stellar motions indicates that over
one million times the mass of our
Sun is somehow confined to a region
less than a fifth of a light-year across.
Astronomers interpret
these observations as strong evidence that the
center of our Galaxy
is home to a very massive
black hole.
