Feder Observatory

A Blog for Minnesota State University Moorhead's Paul P. Feder Observatory

Archive for the ‘Data Reduction’


Problems with times stamp on 9/11, 9/12, 9/13 0

Posted on September 16, 2013 by Matt

I realized tonight that there was a problem with the observatory computer; the program that keeps the computer’s internal clock synchronized with Internet time servers wasn’t working.

It turns out the problem had nothing to do with that program. The IP addresses of campus DNS servers had changed so DNS lookup was failing.

When DNS was reconfigured the synchronization program reset the computer’s internal clock, adjusting it by -46.089 seconds. In other words, 46.089 seconds was subtracted from the computer’s internal clock.

Prior to tonight (9/16/2013) the last synchronization with the time server was on 8/20/2013 at about 5:45AM.

The bottom line is that the timestamp on images taken on the dates below are likely all off by some amount between 0 and -46 sec, but there is no way to know (at least at the moment) how big that offset is. On any given night the time difference between images should be very accurate. It is only the “absolute” time that is incorrect.

Part II: Aperture Photometry using Astro Image J 0

Posted on March 20, 2012 by Linda

AIPPartII.pdf
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Part II: Aperture Photometry Overview 0

Posted on March 20, 2012 by Linda


AIPPartII.pdf
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Part I: Calbration Example Using Astro ImageJ 0

Posted on March 08, 2012 by Linda


AIPPartID_example.pdf
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Part I: Calibrating Images Overview 0

Posted on March 08, 2012 by Linda


AIPPartI.pdf
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Overview of steps to calibrate images



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