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APOD: 2023 January 17 Á Unexpected Clouds Toward the Andromeda Galaxy
| << Yesterday | 17.01.2023 | Tomorrow >> |
Credit & Copyright: Yann Sainty &
Marcel Drechsler
Explanation:
Why are there oxygen-emitting arcs near the direction of the Andromeda galaxy?
No one is sure.
The gas arcs, shown in blue, were
discovered and first
confirmed by
amateur astronomers
just last year.
The two main origin hypotheses for the arcs are that they really are close to Andromeda
(M31),
or that they are just coincidentally placed
gas filaments in our
Milky Way galaxy.
Adding to
the mystery is that arcs were not seen in previous
deep images of M31
taken primarily in light emitted by
hydrogen,
and that other,
more distant galaxies
have not been generally noted as showing similar oxygen-emitting structures.
Dedicated amateurs using commercial telescopes made
this discovery because, in part, professional telescopes usually
investigate
angularly small patches of the night sky,
whereas these arcs span several times the
angular
size of the
full moon.
Future observations -- both in light emitted by oxygen and by
other elements -- are sure to follow.
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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: M 31 - emission nebula
Publications with words: M 31 - emission nebula
See also: