{
  "subject": "LIGO/Virgo G270580:  Pan-STARRS and ATLAS observations of the skymap",
  "eventId": "LIGO/Virgo G270580",
  "bibcode": "2017GCN.20491....1D",
  "body": "L. Denneau, K. C. Chambers, J. Tonry, M. E. Huber (IfA), D. R. Young (QUB), \nC. W. Stubbs (Harvard),  S. J. Smartt, K. W. Smith (QUB), \nM. Coughlin (Harvard), T.-W. Chen (MPE), H. Flewelling, A. Heinze, \nE. A. Magnier (IfA), A. Rest (STScI), B. Stalder (IfA), A. S. B. Schultz, \nC. Waters, R. J. Wainscoat, H. Weiland (IfA), D. E. Wright (QUB), \n\nThe optical wide-field imaging systems ATLAS (see Tonry et al. GCN 20377)  \nand Pan-STARRS1 (see  Chambers et al. GCN 20383 ) were both \nobserving part of the northern  arc of  G270580 of the LALInference map \nfor Burst reconstruction (Veitch et al. PRD, 91,  04200, as released in GCN 20486). \nThese observations were taken during the night of 2017-01-20 UT, just a \nfew hours after the GW source was detected.\n\nThese were mostly normal survey operations, with some pointed PS1 \nfootprints in z and y filters close to the end of the night in Hawaii. \nNot enough dark hours were available to allow the sky map to be targeted \nand mapped out in full. \n\nThese (mostly) serendipitous footprints for the night of 2017-01-20 UT \nhave been uploaded in two plots on GraceDB. \n\nATLAS covered 209 sq deg. (all post-detection of G270580) which corresponds\nto a 10% likelihood of covering the position of the source.  They were taken \n1.5 - 3hrs after G270580 detection, reaching AB mag of o~19 (orange filter)\n\nPan-STARRS1 covered an area of 95 sq. deg. of the likelihood arc \n(pointings which lie on non-zero probability regions)  equating to 5% \nprobability of containing the source. These were take approximately \n2-4hrs after G270580 detection, reaching AB mag of i,z ~ 20 and y~19. \n\nAnalysis is ongoing and any transients will be report. \n\nWeather permitting, we will target much larger regions beginning on \nthe night of 2017-01-21 UT.",
  "createdOn": 1484959945000,
  "format": "text/plain",
  "email": "s.smartt@qub.ac.uk",
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Tyler Barna at University of Minnesota <tylerpbarna@gmail.com>",
  "editedOn": 1744224406726,
  "circularId": 20491,
  "submitter": "S. J. Smartt at Queens U Belfast  <s.smartt@qub.ac.uk>",
  "version": 2
}