Physics Photo of the Week
January
21, 2011
The Trifid Nebula - Discussion by Nao Kimura
Trifid
Nebula,
also
called Messier 20 is located about 5200 light years from
the Earth, in Sagittarius. It is right North of M8. And also, on its
North East direction, there is M21 open cluster. It is believed that it
was discovered in 1750. It is called “Trifid” because the Nebula looks
like it is divided into three parts. It is because there is a dark
nebula in front of M20. M20 has different characteristic in its North
part and its South part. In the North, it is a blue reflection nebula,
and in the South, it is a red emission nebula. A reflection nebula is a
nebula that is visible because its dark nebulas reflect other star’s
lights. An emission nebula is formed by many kinds of ionization gas
that radiate many different colors. It is also called HⅡ region due to
the ionized hydrogen. And there are about 120 of O-type young stars and
also Star clusters. Those stars radiate very intense ultraviolet
radiation that ionizes the gas in the nebula.
The photo was taken by students in the Contemporary Astronomy class on
August 20, 2010 by Karlyn
Hunt, Casey MacMillan, Jake Gerry,
Nao Kimura, and Laetitia Mead.
Physics
Photo of the
Week is
published weekly during the academic year on Fridays by the Warren
Wilson College Physics
Department. These photos feature interesting phenomena in
the world around us. Students, faculty, and others are invited to
submit digital (or film) photographs for publication and
explanation. Atmospheric phenomena are especially welcome.
Please send any photos to dcollins@warren-wilson.edu.
All photos and discussions are copyright by Donald
Collins or by the person credited for the photo and/or
discussion. These photos and discussions may be used for private
individual use or educational use. Any commercial use without
written permission of the photoprovider is forbidden.
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