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.

2001 July 24
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The Red Spider Planetary Nebula
Credit: Garrelt Mellema (Leiden University) et al., HST, ESA, NASA

Explanation: Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star. Officially tagged NGC 6537, this two-lobed symmetric planetary nebula houses one of the hottest white dwarfs ever observed, probably as part of binary star system. Internal winds emanating from the central stars, visible in the center, have been measured in excess of 1000 kilometers per second. These winds expand the nebula, flow along the nebula's walls, and cause waves of hot gas and dust to collide. Atoms caught in these colliding shocks radiate light shown in the above representative-color picture. The Red Spider Nebula lies toward the constellation of Sagittarius. It's distance is not well known but estimated by some to be about 4000 light-years.

Tomorrow's picture: Chandra Hears a Who

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
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