Observation by Martin Butcher: M74 - The Phantom Galaxy

Uploaded by

Stuart Morris

Observer

Martin Butcher

Observed

2012 Oct 16 - 22:22

Uploaded

2021 Mar 28 - 18:24

Objects

M74

Planetarium overlay









Constellation

Pisces

Field centre

RA: 01h36m
Dec: +15°46'
Position angle: +1°28'

Field size

0°44' × 0°30'

Equipment
  • 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
Exposure

Twenty sub-exposures each 3 minutes long taken at ISO1600

Location

Isle of Colonsay

Target name

M74

Title

M74 - The Phantom Galaxy

About this image

M74 is a large spiral galaxy in the equatorial constellation Pisces. It is about 32 million light-years away from Earth.

Equipment used:- Stock Canon 40D mounted at Prime Focus on Meade LX-90 8” telescope (focal ratio f/10 focal length 2,000mm) with a 0.63x Focal Reducer (giving an effective focal ratio of f/6.3 and focal length of 1,279mm) fitted to its field tripod by an equatorial wedge. Telescope Polar Aligned. LX-90 Periodic Error Correction enabled. Dew Removal straps fitted to the telescope and operating. Telescope driven but unguided. Telescope and camera powered by Mains Power.

Exposure details:- Twenty sub-exposures each 3 minutes long taken at ISO1600. Ambient temperature Zero degrees Celsius.

Processing details:- After quality control 5 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 33 arc minutes x 22 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. Strangely at the same time the humidity and temperature both rose causing it to feel much colder than it had earlier in the night when the temperature was actually lower!



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