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Open Cluster M37


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About this observation
David Davies
Time of observation
20/02/2016 - 00:00
Observing location
Cambridge, UK
QSI 583
40 minutes
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This image by David Davies is of the open cluster M37 in Auriga, one of the richest Messier cluster with over 500 stars brighter than magnitude 15. The cluster is well evolved and contains 35 red giant stars, 24 variable stars and many white dwarf stars. Estimates of its distance from us vary between 4,500 and 6,700 light years, making the cluster at least 33 light years across.

David reports that he can see several deep red stars below (south) of the cluster and has identified just two galaxies - PGC 143056 a mag 17 face on spiral, near the top, centre, and PGC 168984, an inclined spiral of unknown magnitude to the left of it.

When planning this image David also saw that the faint open cluster King 8 was nearby and so composed the image to also capture King 8. King 8 has a magnitude of 11.2 and comprises several hundred magnitude 15 stars; it can be found to the right of centre near the top of the image. King 8 is thought to be a relatively young cluster of low-metallicity stars in the galactic plane.

Technical details for the image are:
40 minutes each of RGB data in 5-minute subs;
The image is 106 x 141 arc minutes at 2.62 arc sec per pixel

Telescope: Skywatcher Equinox ED80 plus 0.85 reducer at F/5.3
Camera: QSI 583 plus Astrodon RGB filters
Guiding: Lodestar
Mount:modified Skywatcher NEQ6

Nebulosity; Scopefocus; PHD2: EQMOD; Carte du Ciel; Deep Sky Stacker, PixInsight; Photoshop CC2015

Imaging Location: Cambridge UK

A high resolution version of the image can be found at:

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