M45 - The Pleiades by Valerie Rosen
M45 - The Pleiades by Valerie Rosen
M45 - The Pleiades by Valerie Rosen
M45 is one of the most prominent objects in the night sky. To the naked eye, the Pleiades looks like a miniature Little Dipper. Observers with good vision will easily identify 7 stars, and this gives the Pleiades its nickname - the Seven Sisters. In actuality, the cluster contains over 1,000 stars.

The cluster is a very young cluster, and is dominated by hot, blue stars. M45 is passing through a dust cloud in the Milky Way. As a result, the blue light from the brightest stars reflects off the background dust, thus causing the blue nebulosity surrounding the cluster.

In this image, North is Up. This image is cropped to 95% of the original frame.

Exposure Details
Lens Canon EF 200mm f/2.8L II USM
Focal Length 200mm
Focal Ratio f/3.5
Mount Schaefer GEM - 7 1/2 inch Byers gear
Guiding Piggybacked on Celestron C-8, ONAG On-Axis Guider, Lodestar autoguider, PHD Guiding
Camera Canon 450D - Gary Honis modified (Baader Mod)
Exposure 61 RGB subs of 300 sec @ ISO 200 - 5 hours total
Calibration 30 darks, 30 flats, 30 flat darks, 30 bias
Date December 24, 2013
Temperature 45F
SQM Reading 21.2 (Bortle 4)
Seeing 4/5
Location Pine Mountain Club, California
Software Used Images Plus 5.5 for camera control. Images Plus 5.75 for calibration, stacking, digital development, multiresolution sharpening and star shrinking. Photoshop CS5 used for levels and curves, lab color, selective color, match color high pass filter, screen mask invert, and unsharp mask. Gradient Xterminator for gradient removal. Registar for registration and alignment. Carboni Tools for additional noise reduction and smoothing. HLVG for additional color adjustment.
Notes Although I've posted this image on my website, this image was captured and processed by my daughter, Valerie Rosen (with a little help from me). We were both very happy with how much of the faint outer dust regions Valerie was able to bring out, as well as some beautiful star color. Whlie Valerie has helped me with a few other images, this is the first one where she did everything from start to finish!

And...this image won first place in Astrophotogallery.org's Easy-Cluster category for January 2014!

Plus, Valerie's M45 image was also published in the April 2017 issue of Sky and Telescope magazine in their article entitled "Herschel's Ghosts" (p. 31)!!!