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 astronomer.

2002 August 4
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

Spiral Galaxy NGC 2997 from VLT
Credit: FORS Team, 8.2-meter VLT, ESO

Explanation: NGC 2997 is a grand design spiral galaxy. Its small nucleus and sprawling spiral arms give it a type Sc designation. NGC 2997, pictured above, is speeding away from us at about 1100 kilometers per second, which would place it at about 55 million light years distant, given current estimates of the expansion rate of our universe. NGC 2997 is thought to have a mass of about 100 billion times that of our Sun, but is probably less massive than our own Milky Way galaxy. NGC 2997 is not seen face-on - it is thought tilted by about 45 degrees. NGC 2997 is particularly notable for a nucleus surrounded by a chain of hot giant clouds of ionized hydrogen.

Tomorrow's picture: An Unexpected Aurora

< | Archive | Index | Search | Calendar | Glossary | Education | About APOD | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
& Michigan Tech. U.