TITLE: GCN CIRCULAR NUMBER: 21222 SUBJECT: LIGO/VIRGO G288732: Fermi GBM Observations DATE: 17/06/08 17:03:27 GMT FROM: Rachel Hamburg at UAH LIGO/VIRGO G288732: Fermi GBM Observations R. Hamburg (UAH) reports on behalf of the GBM-LIGO Group: Lindy Blackburn (CfA), Michael S. Briggs (UAH), Jacob Broida (Carleton College), E. Burns (USRA), Jordan Camp (NASA/GSFC), Tito Dal Canton (NASA/GSFC), Nelson Christensen (Carleton College), Valerie Connaughton (USRA), Adam Goldstein (USRA), Rachel Hamburg (UAH), C. Michelle Hui (NASA/MSFC), Pete Jenke (UAH), Dan Kocevski (NASA/MSFC), Nicolas Leroy (LAL), Tyson Littenberg (NASA/MSFC), Julie McEnery (NASA/GSFC), Rob Preece (UAH), Judith Racusin (NASA/GSFC), Peter Shawhan (UMD), Karelle Siellez (GA Tech), Leo Singer (NASA/GSFC), John Veitch (Birmingham), Peter Veres (UAH), Colleen Wilson-Hodge (NASA/MSFC) At the G288732 event time, GBM was observing 89% of the LIGO Bayestar probability map and viewing the entire unocculted sky approximately 67 degrees from Earth center (RA = 197.9, DEC = +19.5). There was a single GBM on-board trigger within 1 hour of event time. However, this trigger was due to a terrestrial gamma-ray flash and unrelated to the G288732 event. The untargeted ground-based search of GBM data for short-duration GRBs (Briggs et al., in prep) found no candidates close in time to G288732. The targeted search of the GBM data ([1], [2]) also did not find a significant gamma-ray signal. This search processes time scales of 0.256 to 8.192 s within 30 s of the LIGO event. No interesting gamma-ray candidate was found within this time window. Further analysis and upper limits will be reported later. [1] L. Blackburn et al. 2015, ApjS 217, 8 [2] A. Goldstein et al. arXiv:1612.02395