
Object Information:
The Pleiades (M45)
Magnitude - 1.2
Type - Bright open cluster associated with a reflection nebulae,
Constellation - Taurus,
Distance - 410 light years,
Size - The dipper shaped asterism comprised of the cluster's brightest
members is about
7 light years across. The entire open cluster spans as much as 20 light
years.
Description: This bright open cluster is perhaps one of the best known objects in the skies. Under ideal visual observing conditions nine stars can be seen in the dipper shaped asterism at the center of the cluster. However, there are nearly 300 (mostly faint) confirmed Pleiades members. The blue color is star light reflecting from a dust cloud that the cluster just happens to be moving through. Burnham's Celestial Handbook reports that the Pleiades group is one of the nearest open or "galactic" star clusters. The nine brightest members are concentrated in a region approximately 7 light years in diameter. All of the brightest members are "B" type stars. Eta Tauri, also known as Alcyone, is the brightest member of the cluster and is nearly 1000 times more luminous than the Sun. It is also estimated to be 10 times more massive than the Sun. This star cluster has had a prominent role in the mythology of many cultures. An interesting treatment of this history and mythology can be found in Burnham's Celestial Handbook.
Imaged at:
Mt. Laguna, San Diego County, California,
Elevation - 5500 feet
Equipment:
Optics - Takahashi Epsilon 160 Astrograph
Mount - Losmandy G-11
Camera - Nikon FM
Film - Kodak Ektachrome E200
Processing - Pushed one stop
Focal Reducer/Field Flattener - None
Exposure Information:
September 21, 2001,
Median combination of four 35 minute exposures,
Image Processing Software: Images registered and combined with RegiStar, final processing with PhotoShop 6.01, grain reduction with the "Grain Surgery" Photoshop plug-in.
All the images in this site are © Copyright 2003 by Dean
Jacobsen.
Any use of these images without the prior written consent or
knowledge of the author is strictly prohibited.
Contact Dean at deanjacobsen@adelphia.net
for more information.