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.

2002 July 31
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Henize 3-401: An Elongated Planetary Nebula
Credit: R. Sahai (JPL/NASA) et al., HST, NASA, ESA

Explanation: How do dying stars eject their outer layers? Stars that create elegant planetary nebulas like Henize 3-401, pictured above, are not unusual, causing speculation that, one day, our own Sun may look like this. Henize 3-401 is one of the most elongated planetary nebulas yet discovered, a particularly odd feat for a seemingly round star. Perhaps, some astronomers hypothesize, the elongated shape gives a clue to the expulsion mechanism. Genesis hypotheses include that the outer layers of gas are funneled out by the star's own magnetic field, and that a second unseen star is somehow involved. After the gas disperses in a few thousand years, only a white dwarf star will remain. Henize 3-401 lies about 10,000 light years away toward the constellation of Carina.

Tomorrow's picture: seeing spots


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