Observation by Martin Butcher: M77 - Barred spiral galaxy

Uploaded by

Stuart Morris


Martin Butcher


2012 Oct 16 - 23:31


2021 Apr 01 - 19:51



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Field centre

RA: 02h42m
Dec: +00°00'
Position angle: +1°24'

Field size

0°31' × 0°20'

  • Meade LX-90 8" telescope fitted to its field tripod by an equatorial wedge.
  • LX-90 Periodic Error Correction enabled.
  • Dew Removal straps fitted to telescope and camera lens
  • Telescope and camera powered by Mains Power.
  • Stock Canon 40D with 200mm f/2.8 lens stopped down to f/4
  • Telescope driven but unguided

Sixty one sub-exposures each 60 seconds long taken at ISO1600


Isle of Colonsay

Target name



M77 - Barred spiral galaxy

About this image

M77 is a Barred Spiral Galaxy, in the constellation Cetus, and is an example of a Seyfert galaxy.


Exposure details:- Sixty one sub-exposures each 60 seconds long taken at ISO1600. Ambient temperature minus one degree Celsius.

Processing details:- After quality control 29 sub-exposures calibrated with Dark, Flat-field and Bias Master frames and then combined in Images Plus. Further processing conducted in Images Plus, with sharpening in Photoshop CS5 and noise reduction in Noise Ninja. Image rotated so that North is at the top. Image cropped to give field of view of 22 arc minutes x 15 arc minutes.

Narrative description:- One day after New Moon. The Moon had already set. The weather was cold, with patches of cloud and calm with no dew. During the sequence of exposures an intermittent breeze got up causing several images to be subsequently discarded because of star trailing.

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