Astronomy Picture of the Day
Discover the cosmos!
Each day a different image or photograph of our fascinating universe is
featured, along with a brief explanation written by a professional
October 19, 1995
Globular Cluster M5
Telescope photograph by David Malin
The globular cluster
M5, pictured above, contains
roughly 100,000 stars.
These stars formed together and are gravitationally bound. Stars orbit the
centre of the cluster, and the cluster orbits the centre of our Galaxy. So
far, about 160
are known to exist in a roughly spherical halo around the
do not appear spherically distributed as viewed from the Earth, and this
fact was a key point in the determination that our
not at the centre of our
Galaxy. Globular clusters are very old. There is a straightforward
of determining their age, and this provides a very interesting lower limit
on the age of our universe of about 14 billion years.
Tomorrow's picture: Asteroid Gaspra's Best Face
| About APOD
Authors & editors:
NASA Technical Rep.:
Specific rights apply.
A service of:
Michigan Tech. U.