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.

July 10, 1998
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

NGC 1531/2: Interacting Galaxies
Credit: W. Keel, R. White III, and C. Conselice (University of Alabama)

Explanation: This dramatic image of an interacting pair of galaxies was made using the 1.5 meter telescope at the Cerro Tololo Inter-American Observatory near La Serena, Chile. NGC 1531 is the background galaxy with a bright core just above center and NGC 1532 is the foreground spiral galaxy laced with dust lanes. The pair is about 70 million light-years away in the southern constellation Eridanus. These galaxies lie close enough together so that each feels the influence of the other's gravity. The gravitational tug-of-war has triggered star formation in the foreground spiral as evidenced by the young, bright blue star clusters along the edge of the front spiral arm. Though the spiral galaxy in this pair is viewed nearly edge-on, astronomers believe the system is similar to the face-on spiral and companion known as M51, the Whirlpool Galaxy.

Tomorrow's picture: Sleeping Beauty

< 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.