NGC 5466 on a terrible night

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menardre
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Joined: Tue Jan 17, 2012 6:09 pm

NGC 5466 on a terrible night

Unread post by menardre »

A couple of nights ago I tried to image M5. I had a lot of difficulty getting platesolve to work . I use ASTAP through SGP and have never had a problem. Platesolving and target centering have always been quick and spot-on. I tried several attempts to get M5 in position even falling back to the tried and true ' when all else fails, reboot your computer'. Eventually I just packed up and went to bed.

Last night I went out with the goal of determining why platesolving with ASTAP did not work. I had setup different profiles using Platesolve2 and 'no platesolve' just in case. I decided to use the globular cluster NGC 5466 as my test case since it is in a good part of the sky (Bootes). The sky was terrible. It was so hazy that I could only see a few bright stars... but I pushed on anyway. I just turned everything on from the previous night, used the same profile/configuration, and lo-and-behold the ASTAP successfully platesolved. I did have a bit of a problem getting the rotation angle correct, but otherwise NGC 5466 was centered. So I pushed on and tried to capture some images. I was able to acquire 50 images of 1 minute with 2x2 binning and gain 100. I had ZWO ASI290 attached to 5 inch refractor for autoguiding using PHD2 but had to monitor it closely since the haze and high level clouds routinely caused it to loose stars and stop autoguiding. I had to reset the autoguider several times to force it to find new stars and adjust the exposure times. I finally gave up after about 50 images when the skies got really cloudy. I then took 50 flats (.15 sec).

Since I took all of those images, I decided to give image processing a try with Pixinsight. Since the sky was so murky, I did not hold out any hope for a good result. SInce this is a globular cluster, the image processing is straight forward... no need to try and pull details of of nebula. I am actually surprised at the result. Not bad for the conditions.

NGC5466 is a sparse globular cluster with no apparent core. It is about 51,800 light years from Earth and has an apparent magnitude of 10.5. This globular is unusually metal poor. You can also see the galaxy PGC 50187 to the left of the cluster.


Roger
NGC 5466 Master_DBEdiv_EzDN._PCC_ArcSinH_HT_DC_Curves_HT.jpg
NGC 5466 Master_DBEdiv_EzDN._PCC_ArcSinH_HT_DC_Curves_HT.jpg (4.65 MiB) Viewed 359 times
Roger M.
Celestron CPC1100 EDGE, Stellarvue 130T refractor dual mounted on iOptron CEM120 on permanent pier mounted in Observatory. Imaging camera ZWO ASI2600 OSC, guide camera Lodestar or ZWO ASI290MM.
Chuck
Posts: 285
Joined: Tue Mar 31, 2015 1:14 pm

Re: NGC 5466 on a terrible night

Unread post by Chuck »

Roger, nice shot under the circumstances. The night sky hasn't been too AP friendly lately.
Chuck M.

Meade 8" LX200 Classic OTA
iOptron CEM40EC and MiniPier on Meade classic field tripod
Canon EF 200mm f/2.8L II
Canon 7D Mark II
ZWO 60mm f/4.6 GS with ASI120MM-S camera
Starizona SCT Corrector II and Virtual View 2" Rotating Visual Back
Pegasus Astro Pocket Powerbox
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