Physics Photo of the Week
November
19,
2010
The Pleiades - Photo assisted by Max
Hunt and Alex Blume
(Contemporary Astronomy
Discussion by Casey MacMillan
The Pleiades, also known as the
Seven Sisters and M45, is an open star cluster, a group of stars that
were formed from the same giant molecular cloud. Giant molecular clouds
are enormous assemblages of molecular gas with masses of 104–106 times
the mass of the sun (Comins, N, & Kaufmann, W., 2008).
The Pleiades is seen naked eye, and is visible in the northern
hemisphere from late fall into early winter. This cluster contains over
3000 stars, is about 400 light years away, and is about 
13
light
years across (Nemiroff, R, & Bonnell, J, 2006). The age of
the Pleiades star cluster amounts to around100 million years.
There are nine main stars in the Pleiades star cluster Asterope,
Taygeta, Maia, Celaeno, Electra, Merope, Atals, Pleione, and Alcyone
(Gibson, S).
The negative photo at right shows the contrast of the faint stars more
easily. The photos were taken using a Digital SLR camera
piggy-back mounted onto a tracking telescope. The telescope was used
only to track the stars; the camera was fitted with a 300 mm focal
length lens. 23 images were made with a 10 second exposure at ISO
800, f/5.6. The 23 images were digitally stacked to produce the
final image.
References
Comins, N, & Kaufmann, W.
(2008). Discovering the Universe. New York, NY: W.H. Freemen and
Company.
There will be no Physics Photo of the Week next week due to
Thanksgiving break at Warren Wilson College. The next Physics
Photo of the Week will be published on Dec. 3, 2010.
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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