Interacting Galaxy System KPG 592 (NGC 7769, NGC 7770, NGC 7771)

[deepskytraveler]

Constellation: Pegasus

NGC 7769, UGC 12808, MRK 9005
Type: Galaxy, AGN LINER
Morphology: (R)SA(rs)b
RA: 23h 51.1m
Dec: +20° 09’ 01”
Mag: 12.0v
SB: 12.8
Size: 1.6’x 1.6’

NGC 7770, MCG+03-60-034, UGC 12813
Type: Galaxy
Morphology: S0/a?
RA: 23h 51.4m
Dec: +20° 05? 47?
Mag: 13.8v
SB: 13.3
Size: 0.9’x 0.8’

NGC 7771, MCG+03-60-035, UGC 12815
Type: Galaxy, star-burst
Morphology: SB(s)a
RA: 23h 51.4m
DEC: +20° 06? 43?
Mag: 12.2v
SB: 13.1
Size: 2.3’ x 1.1’

The three galaxies (NGC 7769-7771) comprise this interacting galaxy system known as KPG 592. The KPG identifier (Karachentsev Pairs of Galaxies) is from the 1972 work by Igor Karachentsev “Isolated Pairs of Galaxies in Northern Hemisphere.” This trio of 12th to 14th magnitude galaxies lie within the Great Square of Pegasus, about 200 million light-years away.

KPG592.gif

KPG592-group.jpeg


NGC 7769 and NGC 7771 are both 12th magnitude spirals, about 2' apart. NGC 7769 is the westernmost member of the trio. It is round with a bright, compact center, while NGC 7771 is highly elongated east-west with a star-like nucleus. NGC 7770, located immediately southwest of NGC 7771, looks at first like a 13.5-magnitude star, but at high magnification reveals itself as a dense, fuzzy smudge of light. NGC 7770 is a lenticular galaxy with a double nucleus oriented east-west.

KPG 592 Finder Chart.jpg

7771A chart.png

The galaxy in the proceeding finder chart labeled MAC 2351-2006 has been cataloged as NGC 7771A. NED data indicates its magnitude at 17.1v. Current studies indicate NGC 7771 is undergoing a direct encounter with NGC 7769 and NGC 7771A. There is an enormous counter-tail suggesting that both galaxies have already passed very closely. 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.

Before you go explore I leave you this image of the KGP 592 galaxy system to ponder.

KPG 592 Galaxy System.jpg
Image by Kent E. Biggs, Columbus TX

Now it is your turn. Give it a go and let us know.