MDM Trouble Report for 2016 Aug 07

Telescope: 2.4m
Observer(s): Yiseul Jeon, Donghoon Son (Seoul National University)
Instrument: OSMOS/B

Problem(s) Encountered:

1) The guiding system did not work: the guide star showed oscillations.

At 1:30AM, our target was located at 
RA=01 40 35.00, Dec=+23 44 51.0
Airmass=1.4, HA=-3 17 30
and Rotator Angle=67.1 (WS=10mph, WD=260)

When we started the guiding, the guiding system did not work well.
The graph of the guide CCD showed oscillations (+-10pix). 

a) I used the Angle of the guide CCD as -90-67.1=-157.1, so that is not the reason. 
b) The wind came from the West and this target was located in East. 
It seems that the wind was not the reason. 

I moved the telescope to the West target for testing and it had the same problem.
I just waited because, if the airmass got smaller the guiding condition can be better. 

2) At 2:30AM, the size of the guide CCD image when I took an exposure was started to be small. 
At 2:30AM, 
I found that the guide star was gone and tried to expose new one. 
After I selected the Expose radio button and hit Start, 
only a small size of image was taken, not a full-frame picture.
I could not fix this. 


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Submitted on 2016 Aug 8 [5:53:56]