Observation by Mike Greenhill-Hooper: Pegasus triplet NGC7771

Uploaded by

Mike Greenhill-Hooper

Observer

Mike Greenhill-Hooper

Observed

2026 Oct 15 - 20:00

Uploaded

2026 Oct 25 - 16:08

Objects

NGC7771
NGC7769
NGC7770

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Constellation

Pegasus

Field centre

RA: 23^h51^m
Dec: +20°08'
Position angle: +131°34'

Field size

0°22' × 0°13'

Equipment

Telescope: 20" f/4 Obsession Dobsonian; Paracorr coma corrector
ASI294MMPro with LRGB filters

Exposure

4x300 frame live stacks for each filter; 1s exposure, gain 450, temp -10C, dark and flats corrected

Location

Miradoux, S.W. France

Target name

NGC7771

Title

Pegasus triplet NGC7771

About this image

Images taken with SharpCap Pro (live stacking), processed with GraXpert, Siril, Affinity Photo and AstroSurface. Quite a difficult target due to dim nature of the galaxies, one of which is magnitude 13.8. The images were quite noisy and I could not capture the foreground galactic "cirrus" that has been imaged by some. The background is therefore rather uneven. I chose to use 1 second exposures in the stacking, but now think that this was partly responsible for the greater noise. There are tidal interations between the galaxies, situated at a distance of around 200 million light years.

Files associated with this observation

NGC7771 M GREENHILL-HOOPER_2_ 151026 Combined 1 reproc AS galaxies.jpg (603.9 kB)

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