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The four galaxies in this two panel mosaic, with a disposition that reminds us of the Constellation Sagitta, conforms the so called Grus quartet. They are identified as (from left to right) NGC 7599, NGC 7590, NGC 7582 and NGC 7552. In the background, dozens of far away galaxies can be spotted. Probably, the most conspicuous group is Abell 1111, on the upper left corner, just under the 11.36 magnitude blue star CD-42 16271. NGC 7582 and NGC 7552 have an HI bridge between them, a proof that they have been interacting with each other. Both are Seyfert galaxies and have supermassive black holes in their core. In both cases, their black holes have a mass around 20 Million solar masses, as determined by B. Davis et al. in 2014.
Additional Information
Object
Name(s): Grus Quartet. NGC 7582, NGC 7552, NGC 7590 and NGC 7599
Type: Spiral galaxies
RA: 23h 18m 23.5s (coordinates for NGC 7582)
Dec: -42º 22’ 14”
Constellation: Grus
Size (arcmin): 5×2 arcmin (NGC 7582)
Magnitude: +11.4
Distance: 70 Mly
Image
Date: 2019-08-27 to 2019-09-19
Location: iTelescope.net, SSO near Coonabarabran, NSW Australia
Size (arcmin): 55×37 arcmin
Telescope: 20” f/6.8 Reflector
Camera: SBIG STX16803 (4096x4096pix)
Guiding: Astrodon MonsterMOAG off-axis guider
Total exposure: 12h 50m (L: 290 min; RGB: 480 min)
Processing: CCDStack, Photoshop CC 2020