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Open Cluster
Messier 45, Pleiades


M45 open cluster October 10, 2018 (click on the image to get a full resolution photo in a new window)
Coordinates/Direction : RA: 03h47m, DEC: +24o07'
Object size : 110'
Object magnitude : 1.6
Object : M45
Date : 2018-10-14
Time (UT) : 20:53 to 23:05
Mount : Star Adventurer
Guide : -
Lens/telescope : Sigma APO 150mm f2.8 (set to f4.0)
Corrector/Barlow : -
Filter : none
camera : Canon 6D, controlled by intervalometer
Film/CCD : Raw
Exp. time : 62x120 seconds, iso1600
Image process tool : AstroImageJ, Fitswork, IrfanView
Processing : crop, level, dark/bias constant subtracted
Weather : clear
Site : Sweden, Stockholm, Ingaröstrand
Comment : A second attempt to catch this object. This time I have done it in late autumn, then it's darker and I did it also with three times the exposure time. Now the nebulosity becomes more visible.

In the Exif data I can read that the camera temperature was 12 C degree, the out door temperature about + 2 C degree. The electronics have heated the camera about 10 C Degrees, normally for this camera is 6 C Degrees. I suspect the extra heating comes from the active Wifi. Part of the heating can also come from the dew heater, it has a bit too strong power, 5 Watt, 2 Watt had been enough.
More to know :

Zoom in around the Pleiades:

M45 Pleiades
Coordinates/Direction : RA: 03h47m, DEC: +24o07'
Object size : 110'
Object magnitude : 1.6
Object : M45
Date : 2018-10-14
Time (UT) : 20:53 to 23:05
Comment : A crop around the Pleiades and more intensive processing to get more nebulosity. It can be processed much more but I prefer to have a mild processing to get it look more natural.

As you notice there is no color of the stars. It comes from the long exposures that oversaturated the readout device at this high ISO setting. Next time I will do much shorter sub exposures but more of them.
More to know :

M45 open cluster 16 august 2016 (click on the image to get a full resolution photo in a new window)
Coordinates/Direction : RA: 03h47m, DEC: +24o07'
Object size : 110'
Object magnitude : 1.6
Object : M45
Date : 2016-08-26
Time (UT) : 22:30 to 23:14
Mount : Star Adventurer
Guide : -
Lens/telescope : Sigma APO 150mm f2.8 (set to f4.0)
Corrector/Barlow : -
Filter : none
camera : Canon 6D, controlled by intervalometer
Film/CCD : Raw
Exp. time : 19x130 seconds, iso1600 (the exif data say 129 sec but it should only had been 60 sec)
Image process tool : Fitswork
Processing : crop, level, cal in camera dark/bias subtracted
Weather : clear
Site : Sweden, Stockholm
Comment : M45 is an open clusters, small islands of stars. This one also have a blue nebulosity.
The reason that I took this photo was to do a test of my new light portable mount, a Star Adventurer. One difficulty is to aim the RA axis for the polar star. I didn't expected much from this photo. 150mm is a long focal length in this case but it worked pretty well. Take a look of the full resolution photo and look at the stars, they are almost round, not elongated as I espected.
More to know : Wikipedia:
https://en.wikipedia.org/ wiki/ Pleiades

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