Under a full moon

June 16 was just one day past full moon. Between 10 and 11PM the moon was still low to the southeast which offered a test for using the DSI-2 under fairly adverse conditions. Randolph, MA where I live is already very light polluted with poorly shielded sodium vapor lights. Adding to the challenge, the  local elementary school in whose parking lot I do my local observing has both broadband mercury vapor along with sodium vapor lighting.

Messier 3 just past full moon

After setting up the scope it took longer than usual to iterative align the 127ED because I forgot about the problems posed by using Arcturus or Spica as alignment stars. I need to recompile a list of compatible alignment stars which which differ between 3 and 9 hr away from Polaris in R.A.


I chose M3, which rides high in the sky this time of night to image. The globular cluster was obvious at 1s exposures in focus mode. After  creating a fresh set of darks for the night and merging with my old set of darks I acquired two sets of exposures at 2.8 and 4.0s. The 4.0s set were averaged to produce the final image after some histogram, brightness and contrast tweaking.

A few nights in Maryland Part 2

Below is my first DSI-2 image of a galaxy Messier 51. M51 is near the end of the handle of the Big Dipper. As luck would have it a member of the Meade DSI Yahoo discussion group, Bill Rouse announced there is a new supernova or exploding star in M51 also supplying a link to before and after images. I didn't get a chance to image the galaxy until June 8th. Again I did not keep good exposure records. The red arrow in the post processed image points to the exploding star. Exposure was unguided which helps explains the oval shapes of the stars.

A few nights in Maryland Part 1

M3

I was in Frederick, MD for a week with the scope which afforded me couple of opportunities for  a little more DSI-2 imaging. The moon was between a young crescent and first quarter. I like to keep different night sessions separate by creating a date named folder.

It dawned on me to bundle dark frames in a single archive and copy it to the new folder for each night of imaging. This improves the odds of the Envisage software finding a compatible set of dark frames for the current session. Dark frames are coded for temperature and Envisage complains for more dark frames  if the temperature changes significantly.

M13

Only one night offered half decent transparency. On the first night with any transparency 6/6/11 I managed  bag four  globular clusters i.e., M3, M5, M13 and M53. Because, I'm still in the familiarization mode my record keeping for these was poor. The images appear to the below.

In my next DSO imaging round I will try imaging without the mirror diagonal on the hope it will improve the roundness of the stars. The DSI-2 also offers  options to sharpening during imaging. However, according to Meade you give up some sensitivity

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  M5

M53