This Karchentseva pair is in fact part of a Karachentseva triple: KTG 82. This trio was earlier recognised as such by Holmberg, who added it as nr. 820 to his list of Double and Multiple Galaxies.
NGC7771 = Holmberg 820A = KTG 82C = KPG 592B
NGC7770 = Holmberg 820B = KTG 82B
NGC7769 = Holmberg 820C = KTG 82A = KPG 592A
In October 2017 I logged one observation, using my 14" SCT @ 168x / 29':
NGC7770 and NGC7771 are the ESE galaxies, NGC7769 is the WNW galaxy.
NGC7771 (Holmberg 820A) is the large NNE galaxy of the two ESE galaxies, elongated ENE to WSW, brighter in the middle, with AV it is clear that it's an elongated, brighter core. The nucleus is visible and appears to be just SW of the middle.
NGC7770 (Holmberg 820B) is the small SSW galaxy of the two ESE galaxies, small, slightly fainter than NGC7770 and slightly elongated ENE to WSW. Even in brightness without AV, with AV gradually slightly brighter in the middle.
The faint galaxy NGC7771A (PGC214933) to the west is not visible.
NGC7769 (Holmberg 820C) is the WNW galaxy: A slightly north-south elongated, oval glow, brighter in the middle. With AV the nucleus is visible along with a faint, outer halo.
Rated it 6/10.
Holmberg 820-1.jpg Holmberg 820-2.jpg Holmberg 820-3.jpg
Click here for the observing guide for this week's OOTW.