//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10428 SUBJECT: GRB 100216A Short, hard GRB detected in ground analysis of Swift-BAT data DATE: 10/02/19 00:32:34 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift J. R. Cummings (NASA/GSFC/CRESST), S. D. Barthelmy (GSFC), D. B. Fox (PSU), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), and D. M. Palmer (LANL) report on behalf of the Swift team: At 10:07:00 UT, Swift-BAT detected GRB 100216A as a rate peak (trigger# 412522), but no source was found onboard. A source was detected in ground analysis at RA, Dec 154.263, +35.524, which is RA (J2000) 10h 17m 03.2s Dec (J2000) +35d 31' 27.5" with an estimated 90% containment of 3 arcmin. The source was detected at a significance of 6.8 sigma in the ground analysis. This level ordinarily indicates a real source, but may have been reached by chance a few times in the past in similar BAT images. The maskweighted and raw lightcurves, however, do appear to be consistent with this location being the source of the burst. This position was 41% coded in BAT. This burst was also detected by Fermi GBM (trigger 288007622) at a best ground- analysis position of RA, Dec: 166.9, 56.6 with an estimated uncertainty of 6.6 degrees (Gruber, private communication). The entire GBM error circle was in a highly-coded region of the BAT FOV, and no credible peak was found any closer to the GBM position. The burst as seen by BAT consisted of a single peak lasting 0.3 seconds. The power-law index of the spectrum was 0.6 +/- 0.3. The fluence in the interval 15-350 keV was (4.7 +- 3) x 10^-8 erg/cm2. There was no automated followup because the source was not detected onboard. The detailed data on the burst was not available until two days after the burst. We note that there is a bright (g'=17.2 mag), DSS-resolved galaxy, KUG 1014+357 (aka LEDA 86918, aka SDSS J101700.25+353118.9) at redshift z = 0.038, within the BAT localization region. Given the possibility of a low-redshift origin for this event, and although detectable X-ray emission from short bursts rarely lasts so long, a limited Swift TOO campaign has been requested and approved. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10429 SUBJECT: GRB 100216A: Keck imaging DATE: 10/02/19 11:57:11 GMT FROM: Daniel Perley at U.C. Berkeley D. A. Perley (UC Berkeley), J. Meyers, E. Hsiao, N. Suzuki, P. Nugent, S. Perlmutter (LBNL), S. B. Cenko, and J. S. Bloom (UCB) report: We acquired imaging of the field of short-hard burst GRB 100216A (Cummings et al., GCN 10428) on 2010-02-19 starting at 07:31 UT, using LRIS on Keck 1. A total of 660 seconds of imaging was acquired in R-band and 900 seconds in g-band simultaneously. The imaging covers approximately 90% of the BAT error circle including the nearby galaxy mentioned in GCN 10428, a barred spiral at z=0.0378. In a preliminary reduction of the R-band frames we identify no new source within the field, down to the SDSS limit of approximately R>22 mag. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10435 SUBJECT: GRB 100216A: XRT Refined Analysis DATE: 10/02/19 23:51:55 GMT FROM: Antonia Rowlinson at U.of Leicester A. Rowlinson (U. Leicester), K. Page (U. Leicester) and N. Lyons (U. Leicester) report on behalf of the Swift-XRT team: We have analysed 9.9 ks of XRT data for GRB 100216A (Cummings et al. GCN Circ. 10428), from 214.4 ks to 249.2 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. We do not detect any fading source within the BAT refined error circle of Cummings et al. (GCN Circ. 10428). A source is detected within the BAT refined error circle at RA, Dec = 154.25836, +35.56772 which is equivalent to: RA (J2000): 10h 17m 2.0s Dec (J2000): +35d 34' 3.8'' with an uncertainty of 5 arcsec (radius, 90% confidence) and is likely to be the known X-ray source 1RXS J101702.9+353404. This source has a count rate of 0.004 count s^-1, corresponding to a flux of 2.6e-13 erg cm^-2 s^-1, however fading cannot be determined at this time and futher observations are being planned. The three sigma upper limit 0.3 - 10 keV count rate for a source at any other position within the BAT error circle is 6e-4 count s^-1, which corresponds to an observed flux limit of 2.3e-14 erg cm^-2 s^-1 (assuming a typical count-to-observed flux conversion factor of 3.8e-11 erg cm^-2 ct^-1, Evans et al., 2009, MNRAS, 397, 1177). The results of the XRT-team automatic analysis are available at http://www.swift.acc.uk/xrt_products/00020127. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10442 SUBJECT: GRB 100216A: Swift/UVOT Observations DATE: 10/02/20 05:01:15 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and A. Rowlinson (U. Leicester) report on behalf of the SWIFT-UVOT team: We have analysed 9787 ks of UVOT data for GRB 100216A (Cummings et al., GCN Circ. 10428), from 214.4 ks to 249.2 ks after the BAT trigger. The data are entirely in the UVW2 filter. We identify a source within the error circle of the XRT position given by Rowlinson et al. (GCN Circ. 10435) with a UVW2 magnitude of 17.59 +- .03 and a position of 154.25872, +35.56806, which is equivalent to: RA(J2000) = 10h 17m 02.09s Dec(J2000) = +35d 34m 05.0" with a 90% confidence interval of 0.6 arc sec. However, this source is also seen in the Digital Sky Survey and exhibits no fading or measurable variability over the 35 ks of observations. It is likely the ultraviolet counterpart to the known X-ray source 1RXS J01702.9+353404 identified by Rowlinson et al. We show no other bright source near the XRT position to a 3-sigma upper limit of UVW2=22.2. The quoted magnitudes have not been corrected for the expected Galactic extinction along the line of sight corresponding to a reddening of E_{B-V} = 0.10 mag (Schlegel, et al., 1998, ApJS, 500, 525). All photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627).