Galaxies NGC 7770 & NGC 7771

Galaxies NGC 7770, NGC 7771, and NGC 7771A

Galaxies NGC 7770 & NGC 7771; CCD image thru 20 inch

This is a 10 minute exposure with an ST-6 CCD camera thru Kopernik's 20-inch F/8.1 Ritchey Chretien Cassegrain telescope. The field of view is about 5x7 arc minutes with North at the top.

Click here for a recent CCD image taken with the Palomar 200 inch telescope.

Barred spiral galaxy NGC 7771 is a part of a triplet of galaxies, consisting of small lenticular galaxy NGC 7770 to the south and the edge-on disk galaxy recently named NGC 7771A to the west. Spiral Galaxy NGC 7769, just outside of the Kopernik image, lies a little further west. NGC 7771 is undergoing a direct encounter with both NGC 7771A and NGC 7769. There is an enormous counter-tail suggesting that both galaxies have already passed very closely. These galaxies have been observed in radio (click here for VLA radio map), infrared, ultraviolet and x-ray. Radio observations show that entire system is embedded in a common envelope of cold molecular hydrogen.

NGC 7771 has a bright center with clumpy knots of emission along the central bar. Two arms extend off the base; the southern arm ends in a knot of bright emission while the north arm ends in a luminous arc. An arc is also seen extending away from the joint between the bar and the southern arm to surround the companion NGC 7770.

NGC 7770 possesses two nuclei oriented east and west of one another.

NGC 7770 Magnitude: 14.4 RA: 23h 51m 22.6s Dec: +20° 05' 54" Epoch 2000 Size (mins): 0.8' x 0.7' Distance: 225 Million Light Years Diameter: 52,500 Light Years Classification: S0/a? Lenticular or tight Spiral Galaxy (uncertain)	NGC 7771 Magnitude: 12.9 RA: 23h 51m 25.0s Dec: +20° 06' 49" Epoch 2000 Size (mins): 2.5' x 1.0' Distance: 225 Million Light Years Diameter: 163,600 Light Years Classification: SB(s)a Barred Spiral, Galaxy S-shaped
NGC 7771A Magnitude: 17.5 RA: 23h 51m 13.20s Dec: +20° 06' 11.2" Epoch 2000 Size (mins): 0.8' x 0.4' Distance: 216 Million Light Years Diameter: 50,200 Light Years Classification: Galaxy of unknown type

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George Normandin, KAS

February 3rd, 2001