by APOD Robot » Wed Dec 27, 2017 5:07 am
The Horsehead Nebula
Explanation: One of the most identifiable nebulae in the sky, the
Horsehead Nebula in
Orion, is part of a large, dark,
molecular cloud. Also known as
Barnard 33, the unusual shape was first
discovered on a
photographic plate in the late 1800s. The red glow originates from
hydrogen gas predominantly behind the nebula, ionized by the nearby bright star
Sigma Orionis. The darkness of the
Horsehead is caused mostly by thick
dust, although the lower part of the
Horsehead's neck casts a shadow to the left. Streams of gas leaving
the nebula are funneled by a strong
magnetic field. Bright spots in the
Horsehead Nebula's base are young stars just in the
process of forming. Light takes about 1,500 years to reach us from the
Horsehead Nebula. The
featured image was taken with the large 3.6-m
Canada-France-Hawaii Telescope in
Hawaii,
USA.
[/b]
[url=https://apod.nasa.gov/apod/ap171227.html][img]https://apod.nasa.gov/apod/calendar/S_171227.jpg[/img] [size=150]The Horsehead Nebula[/size][/url]
[b] Explanation: [/b] One of the most identifiable nebulae in the sky, the [url=http://en.wikipedia.org/wiki/Horsehead_Nebula]Horsehead Nebula[/url] in [url=http://www.astro.wisc.edu/~dolan/constellations/constellations/Orion.html]Orion[/url], is part of a large, dark, [url=https://apod.nasa.gov/apod/ap090623.html]molecular cloud[/url]. Also known as [url=http://en.wikipedia.org/wiki/Edward_Emerson_Barnard]Barnard[/url] 33, the unusual shape was first [url=http://www.messier.seds.org/xtra/ngc/b33.html]discovered[/url] on a [url=https://en.wikipedia.org/wiki/Photographic_plate]photographic plate[/url] in the late 1800s. The red glow originates from [url=http://periodic.lanl.gov/1.shtml]hydrogen[/url] gas predominantly behind the nebula, ionized by the nearby bright star [url=http://www.dibonsmith.com/ori_s.htm]Sigma Orionis[/url]. The darkness of the [url=https://apod.nasa.gov/apod/ap061015.html]Horsehead[/url] is caused mostly by thick [url=https://apod.nasa.gov/apod/ap030706.html]dust[/url], although the lower part of the [url=https://apod.nasa.gov/apod/ap081126.html]Horsehead[/url]'s neck casts a shadow to the left. Streams of gas leaving [url=http://www.youtube.com/watch?v=hgTrLozRj40]the nebula[/url] are funneled by a strong [url=https://en.wikipedia.org/wiki/Magnetic_field]magnetic field[/url]. Bright spots in the [url=http://adsabs.harvard.edu/abs/1987AJ.....93.1514Z]Horsehead Nebula[/url]'s base are young stars just in the [url=https://apod.nasa.gov/apod/ap070218.html]process of forming[/url]. Light takes about 1,500 years to reach us from the [url=https://apod.nasa.gov/apod/ap090224.html]Horsehead Nebula[/url]. The [url=http://www.cfht.hawaii.edu/HawaiianStarlight/AIOM/English/CFHT-Coelum-AIOM-Jan2011.html]featured image[/url] was taken with the large 3.6-m [url=http://www.cfht.hawaii.edu/en/about/]Canada-France-Hawaii Telescope[/url] in [url=https://en.wikipedia.org/wiki/Hawaii#/media/File:Hawaii_in_United_States_(zoom)_(US50)_(-grid).svg]Hawaii[/url], [url=https://www.cia.gov/library/publications/the-world-factbook/geos/us.html]USA[/url].
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