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.

2000 October 16
See Explanation.  Clicking on the picture will download 
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Dust and Gas Surrounding Star R Coronae Australis
Credit: F. Comeron, WFI, MPG, La Silla Observatory, ESO

Explanation: Young star R Coronae Australis has a dusty home. The dust is so thick on the upper left of the above photograph that little light from background stars comes through. Thinner dust near the stars reflects light from R Coronae Australis (upper right) and neighbour TY Coronae Australis, giving their surroundings a flowing appearance. Were these stars more massive they would emit light energetic enough to ionize much of the nearly invisible surrounding hydrogen gas, causing it to appear bright red. The unusual structure above the centre is a Herbig-Haro object, a knot of gas ejected from the star that has impacted surrounding gas. R Coronae Australis is about 500 light-years away, while the region shown is about four light years across.

Tomorrow's picture: Galactic Centre Bow Shock


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
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& Michigan Tech. U.