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Pleiades | by Davide Simonetti
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Pleiades

The Pleiades (M45). This is a shot I've been wanting to do for a long time. Previous attempts were unsatisfactory because my 127 Mak has too much focal length for this object and looked straight through it and using a camera lens made unattractive spokes around the stars caused by the iris of the lens. With the 150mm Newtonian scope the framing is pretty much perfect and plenty of nebulosity can be captured. Also the spikes caused by the secondary mirror spider add to the image. Not perfect perhaps but definitely the best attempt so far. This image has been edited sine originally being posted with extra data added and flat files replaced.

 

[Wikipedia] In astronomy, the Pleiades, or Seven Sisters (Messier 45 or M45), are an open star cluster containing middle-aged, hot B-type stars located in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky.

 

The cluster is dominated by hot blue and extremely luminous stars that have formed within the last 100 million years. Dust that forms a faint reflection nebulosity around the brightest stars was thought at first to be left over from the formation of the cluster (hence the alternative name Maia Nebula after the star Maia), but is now known to be an unrelated dust cloud in the interstellar medium, through which the stars are currently passing. Computer simulations have shown that the Pleiades were probably formed from a compact configuration that resembled the Orion Nebula. Astronomers estimate that the cluster will survive for about another 250 million years, after which it will disperse due to gravitational interactions with its galactic neighborhood.[en.wikipedia.org/wiki/Pleiades]

 

68 x 75 second exposures at 400 ISO (one hour and 15 minutes integration time).

68 x dark frames

24 x flat frames

21 x bias/offset frames (subtracted from flat frames only)

 

Captured with APT

Guided with PHD2

Processed in Nebulosity and Photoshop

 

Equipment:

Sky-Watcher Explorer-150PDS

Skywatcher EQ5 Mount

Orion 50mm Mini Guide Scope

ZWO ASI120 MC imaging and guiding camera

Canon 700D DSLR

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Taken on September 20, 2017