GCN Circular 18344

M. Soares-Santos (Fermilab), J. Annis (Fermilab), E. Berger (Harvard) D. J.
Brout (UPenn), H.-Y. Chen (UChicago), P. Cowperthwaite (Harvard), H. T.
Diehl (Fermilab), B. Farr (UChicago), J. Frieman (UChicago), M. Garcia
(CIEMAT/Madrid), R. Gruendl (NCSA), D. Hollowood (UCSC), D. Holz
(UChicago), R. Kessler (UChicago), A. Kim (LBNL), K. Hefner (Fermilab), E.
Neilsen (Fermilab), M. Sako (UPenn), B. Yanny (Fermilab)

On behalf of the DESGW team:

We report on observations done with the Dark Energy camera (DECam) on the
Blanco telescope at CTIO on the night of 2015-09-17 in response to the LVC
trigger G184098. Our observations were delayed by 1 night due to the mag
8.1 earthquake near CTIO.

DECam has a 3 sq-deg field of view, and typically reaches i,z = 23rd
limiting magnitudes for 90 sec exposure times. We covered 5% of the LIGO
probability map in 2h of observing time. We covered 80 sq-deg to 23.25
5-sigma point source limiting magnitude in i,z bands.

Coordinates are given below.

Analysis is underway.

ra dec
105.241671 -69.46246
72.711983 -65.40533
99.430667 -69.84
68.298046 -63.8895
95.986417 -68.35239
110.757033 -68.87642
115.898475 -68.09865
109.488283 -70.73343
103.3931 -71.25164
115.164875 -70.00358
120.35765 -69.0844
65.041267 -62.8751
93.434754 -69.99717
65.802783 -60.8461
62.9234 -59.8316
125.044417 -67.99968
129.235458 -66.77258
68.870837 -61.8606
125.215963 -69.94243
72.150367 -62.8751
62.107867 -57.8027
87.38715 -69.92876
83.908596 -71.39367
81.427092 -69.63706
84.793617 -68.22478
82.565254 -66.48404
79.328883 -67.84927
77.530833 -66.03508

[GCN OPS NOTE(19sep15): This Circular was originally published on 22:20 18-Sep-2015 UT.]