M13 - The Hercules Cluster


Mark Stronge
  Comber, County Down, Northern Ireland
Photo Title
  M13 - The Hercules Cluster
Time and Date taken
  29th August 2003 0000UT
Equipment used
  Meade LX200 10inch SCT, f/3/3 focal reducer, vibration isolation pads
Capturing device used
  Starlight Xpress MX7C
Technical details
  2x60second exposures, stacked in Registax and processed in Paint Shop Pro

After the wonderful view of M13, the Hercules Cluster, at the EAAS Mars Opposition party, we just had to have a go at imaging it. This time we knew it would take a lot longer exposure and more sensitive CCD than the Dimage 7 had. We used our Starlight Xpress MX7C CCD camera. This is a very sensitive colour CCD camera specifically designed for astronomical use that can be used in unguided or guide mode as the CCD has a progressive scan. The chip in the camera is a Sony EXview CCD, with 752x582pixels.

With the Meade 10inch LX-200 on the polar mounting, we fine tuned the tracking by adjusting the mount at 15 minute intervals using the built-in "refined polar alignment" of the LX-200. Every time we did this the tracking and GOTO became more accurate to a point where the GOTO is accurate to less than 2 arc-minutes. This means that subjects will be centred in the eyepiece at high magnifications and the CCD can be slotted in without the hassle of fine tuning the subject in the CCD due to the small area covered by the chip.

The photo below is taken using the Meade 10inch LX200, f3.3 focal reducer and the Starlight Xpress MX7C CCD camera. Unfortunately, because of work commitments, there was only time to take 2 exposures, each 60 seconds long. The telescope was unguided so we were relying on the accuracy of the polar alignment to make sure the stars were round and not streaked. The 2 images were stacked and processed in Registax and then levels adjusted in Paint Shop Pro 8.

M13 The Hercules Cluster



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