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Messier 44 is additionally known as the Praesepe (the manger). A prominent open cluster, M44 is one of the closest Messier objects (577 ly). Only M45, the Pleiades Cluster, is closer to us (444 ly). The cluster itself has a couple of peculiarities. Probably the most important is that, like some other open clusters, its stars have undergone mass segregation, meaning that the more massive stars concentrate in its central region while the lower mass stars (less than 0.7 solar masses) move to the outer regions. Even some less massive stars can “evaporate” from the cluster because they increase their velocity enough to be “expelled” from the cluster. The currently accepted number of stars belonging to the cluster is 872.
This image is a two panel mosaic capturing all the brightest stars in roughly 0.5×1 degrees out of the more than 1.5 degrees that the cluster occupies. It was taken with RGB filters being the Luminance composed with the sum of the RGB masters. Additional 12 hours of Halpha (six on each panel) were taken trying to see whether any background emitting nebulosity was present, but this was negative.
Additional Information
Object
Name(s): Messier 44. NGC 2632
Type: Open Cluster
RA: 08h 40m 23s
Dec: +19º 39’ 59”
Constellation: Cancer
Size (arcmin): 70×120 arcmin
Magnitude: +3.1
Distance: 577 ly
Image
Date: 2021-03-30 to 2021-04-10
Location: Curiosity2 Observatory, New Mexico Skies, Mayhill, NM, USA
Size (arcmin): 53×30 arc min
Telescope: 24” (61 cm) f/6.5 Reflector
Camera: FLI PL16803 (4096x4096pix)
Guiding: Astrodon MonsterMOAG off-axis guider
Total exposure: 6 hours RGB: 2 hours each.
Processing: CCDStack, Photoshop CC 2021