M45 - The Pleiades


Mark Stronge
  Comber, County Down, Northern Ireland
Photo Title
M45 Pleiades
Time and Date taken
0000UT 26th October 2004
Equipment used
Orion ED80mm, Vixen GP mount with WinCTC controller, Vibration isolation pads
Capturing device used
Canon Digital Rebel 300D 6.3 Megapixel
Technical details

ISO800 with long exposures from 90-200seconds. 6 Images stacked in Registax. Processing in Paint Shop Pro 9

It has been quite a while since I have been out doing any astrophotography and this night was not a particularly good one as the Moon was only 2 days from full. In preparation for the lunar eclipse, I decided to test the mount and polar alignment with a long exposure test. The clutch had been slipping on the RA axis but a friend was able to help me clean the gear grease from the washer and rubber which makes up the clutch. While this has helped, I am still having problems with the motor not turning the gears so there may be something loose inside the motor itself. After a few attempts, the motor started tracking and I started imaging. Average exposure was about 100 seconds at ISO800. The final stacked image was very blue, probably due to the light of the silvery moon :-) After doing a fairly nasty histogram stretch, more like a nip and tuck, I corrected the blue sky to black using the black/white point in Paint Shop Pro. I did not do any unsharp masking as all the stars looked great and quite natural in shape, size and colour. Heavy unsharp masking can create an unwelcome hotspot in the centre of each star.

As you can see, Merope's Nebula is visible, as well as some nebulosity around Maia. The stars are trailed very slightly but it does not interfer too much with the detail. Limiting Magnitude is estimated around Mag18.



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