GCN Circular 18335

K. Chambers, M. Huber, E. Magnier, H. Flewelling, C. Waters, J. Tonry, A. Schultz,
N. Primak (IfA, University of Hawaii), S.J. Smartt, K. W. Smith, D. Young,
D. Wright (Queen��<80><99>s University Belfast), C. Stubbs (Harvard)

With the Pan-STARRS1 telescope (3 degree FOV) on Maui, Hawaii, we imaged the northern error
region of the ALIGO GW burst trigger G184098 released on 2015-09-14. In the dawn twilight of
2015-09-17 (14:53-15:31 UT) we took a set of 9 images (3x3 grid), stepping through
RA=129.8503, 132.5503, 135.2503  and
DEC=3.699, 6.399, 9.099
in each of i and z (60s and 45s each respectively). One exposure, with some edge overlap was
taken at each position, producing approximately 63 sq degrees coverage in i and z bands.
A set of y-band images was taken at the central pointing position. The fill factor of the
GPC1 camera on Pan-STARRS1 is about 80%, due to focal plane gaps. Difference imaging
with respect to the PS1 3Pi stacked sky images is ongoing to identify any new transients
candidates. Further imaging will be taken in this pattern as weather allows and reported in the GraceDB
EM observations. Any candidates will be reported to this email list.

[GCN OPS NOTE(19sep15): This Circular was originally published on 20:44 17-Sep-2015 UT.]