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 15, 1999
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

The Sun Oscillates
Credit: GONG, NOAO

Explanation: Our Sun is in a continual state of oscillation. Large patches of the Sun vibrate in and out, back and forth, even as the Sun rotates. One mode of Solar oscillation is depicted graphically above, with blue indicating outward motion, and red indicating inward motion. Although sensitive optical solar observatories can only directly detect surface motions, they give information about vibrations occurring much deeper in the Sun. In helioseismology, these oscillations are being analyzed and are revealing unprecedented information about the density, temperature, motion, and chemical composition of the entire Sun.

Tomorrow's picture: Sprite Lightning

< 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.