MDM Trouble Report for 2016 Apr 27

Telescope: 2.4m
Observer(s): Yiseul Jeon, JaeJin Shin (Seoul National University)
Instrument: OSMOS

Problem(s) Encountered:
1. Dome flat shows a thick line.
We took dome flats and there was a thick line at y=3500.
I found that there exist a line 
from an example figure of dome flat from the web page  OSMOS Long-slit Data Reduction :
http://www.dartmouth.edu/~kevinhainline/osmos_images/flats/domeflat_sample.png
However, our line shows thicker shape. 

2. guide probe did not move. 
The guide probe did not move (at 8:20PM).
Eric let us know a solution. 
We shut down the GUI and powered cycle the MIS box. 
It worked alright. 

3. JSkyCalc failed to find the 'Nearest Bright Star'.
For a pointing procedure, we tried to get information of a nearest bright star
when the telescope pointed the zenith. 
However, JSkyCalc found a star near horizon.
We shut down JSkyCalc and this solved this problem.

4. Failure of data saving 
When afternoon calibration, we tried to take bias images. 
However, data saving failed sometimes. We gave up the bias and moved to take mis flats. 
The flat images saved well.

5. Telescope failed to do tracking. 
After 2 AM, we found that guide stars moved away during the 'autoguider on'. 
In other words, the telescope moved to the direction incleasing RA.
The speed of the moving is similar to the condition of  Track off .
This events were happened when we observe targets:
one was HA=2h and the other one is HA=0h. 
We tried to put our target in slit and sometimes the tracking worked well. 
However, it failed again and we gave up the observation at 4 AM. 

6. Noisy sound from telescope mount
Whole night, there were a noisy sound (scratching something) from dome
and it seems that telescope mount made that noise. 
After parking the telescope, the noise was gone. 

7. Images using 3.0 inner slit shows a line at y=2100.
After 4AM, spctral images using 3.0 inner slit (arc, misflat, skyflat) 
shows a thick line at y=2100.
Figure below shows two misflat images before and after 4AM
with 3.0 inner slit, Blue grism, and 300s exposure time.
https://www.dropbox.com/s/mr9szncbvhucg0e/misflat.tiff?dl=0
Images with 0.9 inner or 1.2 inner do not show this line. 


















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Submitted on 2016 Apr 28 [6:07:22]