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Credit & Copyright: Domingo Pestana &
Raul Villaverde
Explanation:
What created the strange spiral structure on the upper left?
No one is sure, although it is likely related to a star in a
binary star system entering the
planetary nebula phase,
when its outer atmosphere is ejected.
The huge spiral spans about a third of a
light year across and, winding four or five
complete turns, has a regularity that is without precedent.
Given the expansion rate of the
spiral gas, a new layer must appear
about every 800 years, a close match to the time it takes for the two stars to orbit
each other.
The star system that created it is most commonly known as
LL Pegasi,
but also AFGL 3068. The unusual structure itself has been cataloged as
IRAS 23166+1655.
The featured image was taken in near-infrared light by the
Hubble Space Telescope.
Why the spiral glows is itself a mystery, with a leading hypothesis being
illumination by light reflected from nearby stars.
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NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: planetary nebula
Publications with words: planetary nebula
See also:
- The Medusa Nebula
- Jones Emberson 1
- APOD: 2024 February 12 Á HFG1 & Abell 6: Planetary Nebulae
- APOD: 2023 December 24 Á NGC 2440: Cocoon of a New White Dwarf
- APOD: 2023 October 3 Á MyCn 18: The Engraved Hourglass Planetary Nebula
- NGC 1360: The Robin's Egg Nebula
- APOD: 2023 April 16 Á M2 9: Wings of a Butterfly Nebula