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ENR CTIO Blanco 4-m 2018-08-07

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Date: 
Tuesday, August 7, 2018
Telescope: 
CTIO Blanco 4-m
Submitter: 
Segev BenZvi
Submitter Email: 
sybenzvi@pas.rochester.edu
Observer Support: 
Jacqueline Seron
Night Assistant: 
Claudio Aguilera
Also Present: 
Regina Demina, Clara Martínez-Vázquez, Manuel Hernandez
Problems: 
  • Lost guider for exposures 762791 and 762792.
Comments: 

High transparency and few/no clouds, but seeing was >2" FWHM for first half of the night according to DIMM and the DECam astrometry. Poor seeing could have been due to winds at high altitude, which we noticed in the late afternoon.

  • Seeing between 3" and 4" during first quarter. All exposures at airmass>1.4, likely not usable.
  • Used regenerated plan files to focus on lower airmasses starting at 20:50 CLT. Seeing stabilized around 2" during second quarter.
  • Seeing improved to 1.5"-2" after 02:30 CLT.
  • 03:30: seeing dropped to 1.1"-1.3" (0.9" according to DIMM).
  • 04:30: PSF and ellipticity worsened due to wind shake. Night assistant raised the lower shutter.
Conditions: 
General Conditions
Temperature Max: 
14.00
Temperature Min: 
8.00
Humidity Max: 
40
Humidity Min: 
15
Wind Speed Max: 
25.00
Wind Speed Min: 
5.00
Comment: 
Clear but poor seeing before midnight. Conditions improved steadily and stabilized near 1" FWHM (according to DECam) by 03:00 CLT.
1st Quarter
Clouds: 
Clear
Wind: 
Medium
Seeing Value: 
3.00
Seeing Variability: 
0.8
Seeing Source: 
The Telescope I used
Sky : 
1
2nd Quarter
Clouds: 
Clear
Wind: 
Medium
Seeing Value: 
2.00
Seeing Variability: 
0.4
Seeing Source: 
The Telescope I used
Sky: 
0
3rd Quarter
Clouds: 
Clear
Wind: 
Medium
Seeing Value: 
1.70
Seeing Variability: 
0.4
Seeing Source: 
The Telescope I used
Sky: 
0
4th Quarter
Clouds: 
Clear
Wind: 
Medium
Seeing Value: 
1.10
Seeing Variability: 
0.2
Seeing Source: 
The Telescope I used
Sky: 
0
Program: 
Proposal: 
2014B-0404
Target of Oportunity: 
No
Time Observed: 
11.5
Time Engineering: 
0.0
Time lost technical: 
0.0
Time lost weather: 
0.0
Time lost other: 
0.0
Description: 
DECam Legacy Survey
Primary Investigator: 
David Schlegel
Email: 
DJSchlegel@lbl.gov
Institution: 
Lawrence Berkeley National Laboratory
Instrument: 
CTIO 4m DECam
Organization: 
NOAO
Total Program Time: 
11.5
Total Times Time Observed Time Engineering Time lost technical Time lost weather Time lost other Total Program Time
2018-08-07 11.5 0.0 0.0 0.0 0.0 11.5