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.

June 30, 1999

NGC 6934 from Gemini North
Credit: Gemini Obs., NSF, & U. Hawaii IfA

Explanation: What's going on near the center of globular cluster NGC 6934? The blur caused by the Earth's atmosphere has prevented astronomers from discerning individual stars in this unusual environment. Telescopes in space can help, but the new Gemini North telescope took the above picture from the ground. In infrared light, Gemini was able to use its adaptive optic mirrors to resolve stars even near the globular cluster's center. NGC 6934 is a 15 billion-year-old ball of hundreds of thousands of stars. Dating stars in ancient globular clusters like NGC 6934 provide valuable constraints on the minimum age of the universe.

Tomorrow's picture: Moon Rover

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.