//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5904 SUBJECT: GRB 061210: Swift-BAT detection of a short burst DATE: 06/12/10 12:52:43 GMT FROM: Scott Barthelmy at NASA/GSFC J. K. Cannizzo (NASA/UMBC), L. M. Barbier (NASA/GSFC), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), C. B. Markwardt (GSFC/UMD), J. P. Osborne (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. Stamatikos (NASA/ORAU) report on behalf of the Swift Team: At 12:20:39 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 061210 (trigger=243690). Swift did not slew because of the Moon observing constraint -- this burst is 4 deg from the Moon. The BAT on-board calculated location is RA, Dec 144.514, +15.632 which is RA(J2000) = 09h 38m 03s Dec(J2000) = +15d 37' 56" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single spike structure with a duration of about 0.8 sec. The peak count rate was ~27,000 counts/sec (15-350 keV), at ~0 sec after the trigger. No XRT or UVOT observations will be possible until the burst emerges from the spacecraft Moon constraint in about 1.5 days. [GCN OPS NOTE(10dec06): Per author's request, a typo in the first author's initials was corrected from "J, K. C." to "J. K.".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5905 SUBJECT: GRB 061210, Swift-BAT refined analysis of the SHB DATE: 06/12/10 16:39:14 GMT FROM: Scott Barthelmy at NASA/GSFC D. Palmer (LANL), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. K. Cannizzo (GSFC/UMBC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) on behalf of the Swift-BAT team: Using the data set from T-239 to T+478 sec from the recent telemetry downlink, we report further analysis of BAT GRB 061210 (trigger #243690) (Cannizzo, et al., GCN Circ. 5904). The BAT ground-calculated position is RA, Dec = 144.521, 15.613 deg which is RA(J2000) = 09h 38m 05.1s Dec(J2000) = 15d 36' 46.3" with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 30%. The mask-weighted lightcurve has a hard FRED-like spike lasting a total of ~192 msec followed by much weaker, softer emssion lasting out to ~T+90 sec. T90 (15-350 keV) is 85 +- 5 sec (estimated error including systematics). The event-by-event data shows the FRED-like peak is resolved to 3 somewhat overlapping spikes within 60 msec. The time-averaged spectrum from T+0.2 to T+89.6 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.55 +- 0.28. The fluence in the 15-150 keV band is 1.1 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.01 sec in the 15-150 keV band is 5.3 +- 0.5 ph/cm2/sec. The spectrum of the first spike alone (T+0.212 to T+0.760 sec) is also fit by a simple power law model. The power law index of the initial spike is 0.79 +- 0.15. The fluence in the 15-150 keV band is 3.0 +- 0.3 x 10^-7 erg/cm2. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5906 SUBJECT: GRB 061210: MDM Observation DATE: 06/12/10 17:33:58 GMT FROM: Jules Halpern at Columbia U. N. Mirabal & J. P. Halpern (Columbia U.) report on behalf of the MDM Observatory GRB follow-up team: "We observed the entire Swift BAT error circle of short GRB 061210 (Cannizzo et al., GCN 5904; Palmer et al., GCN 5905) in the I band on the MDM 1.3m telescope. Combined exposures obtained in the interval 39-66 minutes after the burst show no new object to a limiting magnitude of I~18.5 in comparison with the USNO-B1.0 catalog, despite high background from the nearby bright moon. This message may be cited." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5910 SUBJECT: GRB061210: Radio Observations DATE: 06/12/12 16:41:45 GMT FROM: Poonam Chandra at U Virginia/NRAO Poonam Chandra (NRAO/UVA) and Dale A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: "We used the Very Large Array to observe the field of view toward GRB 061210 (GCN 5904) at a frequency of 8.46 GHz on 2006 December 12 at 9.81 UT. The peak radio brightness at the BAT ground-calculated position (GCN 5905) is 26 uJy ± 34 uJy. The nearest source in the GRB field of view is at a distance of 3.54 arcmin, cataloged in NVSS and FIRST survey as J093751+153629. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5912 SUBJECT: GRB 061210: Gemini/GMOS Observations DATE: 06/12/13 02:49:20 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko (Caltech), D. B. Fox (Penn State), and P. A. Price (IfA/Hawaii) report on behalf of a larger collaboration: We observed the field of the short-hard GRB061210 (Cannizzo et al., GCN 5904) with the Gemini Multi-Object Spectrograph in imaging mode mounted on the Gemini North telescope. Our first set of observations was taken in r' at a mean epoch of 14:27 Dec. 10 UT (2.1 hours after the burst) and covers ~ 90% of the refined BAT error circle (Palmer et al., GCN 5905). Contamination from the nearby moon significantly affected the sensitivity of these images. A second r' reference epoch was taken the following evening, at a mean epoch of 13:54 Dec. 11 UT (25.6 hours after the burst). Digital image subtraction using the ISIS software package (Alard & Lupton 1998, ApJ, v. 503, p. 325) revealed no variable object anywhere in the field. We place a limit of r' > 23.5 mag for any isolated point-source afterglow emission at the time of the first epoch. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5917 SUBJECT: GRB 061210: Suzaku WAM observation of the prompt emission DATE: 06/12/14 03:07:12 GMT FROM: Yuji Urata at Saitama U Y. Urata, M. Tashiro, K. Abe, K. Onda, Y. Sato, M. Suzuki, (Saitama U.), K. Yamaoka, S. Sugita (Aoyama Gakuin U.), M. Ohno, T. Takahashi, T. Asano, T. Uehara, Y. Fukazawa (Hiroshima U.), T. Enoto, K. Kokubun, K. Makishima, R. Miyawaki (Univ. of Tokyo), M. Suzuki, T. Tamagawa, Y. Terada (RIKEN), K. Nakazawa, T. Takahashi (ISAS/JAXA), S. Hong (Nihon U.), on behalf of the Suzaku WAM team report: "The short GRB 061210 (Cannizzo et al. GCN 5904, Palmer et al GCN 5905) triggered the Suzaku Wideband All-sky Monitor (WAM), which covers the energy range of 50 keV - 5 MeV, at 12:20:39 UT December 10, 2006. The duration T90 was about 0.047 second. The fluence in 100 - 1000 keV of the burst was about 2.02 (-0.33, +0.35) x 10-6 erg/cm2. Preliminary result shows that the time-averaged spectrum is well described by a single power-law model with the photon index 1.55(-0.19,+0.22). All the quoted errors are at statistical 90% confidence level, while systematic errors are not included. The WAM light curve of this event is available at http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/grb_table.html " //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5920 SUBJECT: GRB 061210 : Faulkes North Telescope optical limit DATE: 06/12/14 14:14:46 GMT FROM: Andrea Melandri at Liverpool John Moores U A. Melandri, D. Carter , C. Mundell, A. Gomboc, C. Guidorzi, I.A. Steele, C.J. Mottram, D.F. Bersier, S. Kobayashi, R.J. Smith, M.F. Bode (Liverpool JMU), P. O'Brien, E. Rol, N. Bannister (Leicester) report: "The 2-m Faulkes North Telescope robotically followed up the Swift GRB061210 (trigger #243690, Cannizzo et al) and began observing about 2.4 minutes after the GRB trigger time. Observations were affected by the nearby bright moon (~4.3 degrees) and no new object was found inside the BAT error circle (Palmer et al., GCN 5905). From the acquired set of 3x10 seconds exposures in the R-band we can set an upper limit for the afterglow of R>17.0 at 2.8 minutes (mean time). This message may be cited." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5921 SUBJECT: GRB 061210: Swift XRT analysis - Possible counterparts DATE: 06/12/14 17:03:18 GMT FROM: Olivier Godet at U.of Leicester O. Godet, K. Page, P. Evans, A. P. Beardmore (U. Leicester), D. N. Burrows (PSU), J. K. Cannizzo (LANL) report on behalf of the Swift XRT team: We analysed 26ks of XRT data for the short burst GRB 061210 (Cannizzo et al., GCN Circ. 5904) taken between 2.42 days and 2.72 days after the BAT trigger. Swift observed this burst late due to a Moon constraint. The XRT/PC image shows two sources S1 and S2 in the BAT error circle located at: S1: RA(J2000)=09h 37m 57.55s Dec(J2000)=+15d 36' 30.8" with an uncertainty of 4.1" (90% containment). The source S1 is 110" from the BAT position quoted in Palmer et al. (GCN Circ. 5905). S2: RA(J2000)=09h 38m 05.17s Dec(J2000)=+15d 37' 16.0" with an uncertainty of 4.2" (90% containment). The source S2 is 30" from the BAT position quoted in Palmer et al. (GCN Circ. 5905). The two sources are uncatalogued. We note that a slightly elliptical object located at 12.1" from the position of the source S2 is seen in the DSS images. This corresponds to the source EO1509-0232011 in the APM-North catalogue. It has a r-magnitude of 17.24 and a b-magnitude of 22.12. With the data so far available we can not tell if either S1 or S2 are fading. However, the XRT will continue to observe the field. This circular is an official product of the Swift XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5922 SUBJECT: GRB 061210: Optical sources near XRT positions DATE: 06/12/14 19:27:09 GMT FROM: Edo Berger at Carnegie Obs E. Berger (Carnegie Observatories) reports on behalf of a larger collaboration: "Inspection of our Gemini/GMOS images (GCN #5912) at the positions of XRT sources S1 and S2 (GCN #5921) reveal the presence of several extended optical sources, one of which may be the host galaxy of GRB 061210. Within the error circle of source S1 we detect a single extended object with r=24.8+/-0.2 mag (S1-G1). Similarly, within the error circle of source S2 we detect an extended object with r=24.8+/-0.2 mag (S2-G1), as well as a brighter galaxy with a bulge-dominated morphology on the edge of the error circle with r=21.0+/-0.02 mag (S2-G2), and a third galaxy about 1.5" outside of the error circle with r=22.9+/-0.05 mag (S2-G3). All magnitudes are derived using the zeropoint available on the GMOS website. We note that the elliptical object EO1509-0232011 mentioned in GCN 5921 is not visible in our images (or in DSS2) and it is likely to be a high proper motion star. In the absence of X-ray or optical variability it is unclear which (if any) of these galaxies is the host of GRB 061210. However, if source S2 is shown to be the X-ray afterglow, the most likely host galaxy is S2-G2 given its brightness and consistent location with the XRT error circle." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5924 SUBJECT: GRB061210: Swift/UVOT observations DATE: 06/12/15 00:39:38 GMT FROM: Antonino Cucchiara at PSU Cucchiara A. (PSU), Cannizzo J. (NASA/UMBC) reports on behalf of the Swift/UVOT team: The Swift/UVOT observed the field of GRB061210 starting 2.42 days after the BAT trigger (Cannizzo et al., GCN Circ. 5904). No afterglow optical candidate is detected in either of the XRT error circles in 18.5 ks of exposure time from T+2.42 days to T+3.48 days in U band. We clearly detect the extended source near the candidate S1 (Berger et al., GCN Circ. 5922) at the following coordinates: RA(J2000) = 09:37:57.92 DEC(J2000) = +15:36:32.6 with a 1 sigma error radius of about 0.5 arcsec. The estimated UVOT/U magnitude is 21.0 +/- 0.1. In a second epoch image taken from T+3.5 days to T+3.64 after the trigger the source is still present and it is not fading. The estimated magnitude in 12 ks coadded image is 21.0 +/- 0.1. In the position of the candidate S2 we estimate a 3 sigma upper limit of 22.06. The values quoted above are not corrected for the expected Galactic extinction of E_{B-V} = 0.035 mag (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5925 SUBJECT: GRB 061210: MDM Follow-up Observation DATE: 06/12/15 01:56:04 GMT FROM: Nestor Mirabal at Columbia U N. Mirabal, J. P. Halpern, & J. Corby (Columbia U.) report on behalf of the MDM Observatory GRB follow-up team: "Following our initial observation of the entire Swift BAT error circle (GCN 5906), we continued observing the XRT candidates of short GRB 061210 (Godet et al., GCN 5921) using V, R and I filters on the MDM 1.3m telescope on Dec. 12-13 UT. In a summed 60-minute exposure centered at Dec. 13 09:03 UT, we clearly detect the extended galaxy candidate "S2-G2" reported by Berger (GCN 5922) at coordinates RA(J2000) = 09:38:05.3, Dec(J2000) = 15:37:18.9 (+/- 0.5''). Preliminary photometry yields R ~ 20.9 +/- 0.2 in comparison with the USNO-B1.0 catalog, which is consistent with the value reported by Berger. As an aside, we note the relative high concentration of optical galaxies toward RA(J2000) = 09:37:52.5, Dec(J2000) = 15:36:24.9 that should be tested as a possible galaxy cluster host of this short GRB. This message may be cited." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5983 SUBJECT: GRB 061210: Swift/XRT Astrometry Correction DATE: 06/12/26 14:57:29 GMT FROM: Judith Racusin at PSU J. L. Racusin (PSU), O. Godet, (U. Leicester), J. K. Cannizzo (NASA/UMBC), D. Fox (PSU), and N. Gehrels (NASA/GSFC) report on behalf of the Swift XRT team: We have re-analyzed the full XRT data set of GRB 061210. XRT observed the field of GRB 061210 for a total exposure time of 73 ks between December 12 and December 20, 2006 in Photon Counting mode. Godet et al. (GCN 5921) identified 2 potential X-ray afterglow candidates (S1 & S2). After further observations to characterize fading behavior, we have concluded that S2 is the X-ray afterglow. To further improve the accuracy of the position previously quoted, we performed an astrometric correction using 66 ks of the total exposure time (when the satellite position was stable). In this data set we find 22 serendipitous X-ray sources detected with the XIMAGE detect algorithm with S/N > 3, 6 of which have near-by optical counterparts in the USNO-B1 catalog. We match these sources to obtain a best fit mean frame shift, carefully accounting for several instrumental factors including exposure map correction, and additional hot pixel removal. We calculate the statistical position errors using the empirical fits as described in Moretti et al. (2006, A&A, 448, L9), assuming that the astrometric correction removes the 3.5" systematic error normally applied to XRT positions to account for errors in the star tracker attitude solution. The result of this analysis leads to a mean frame shift from the previously reported position (Godet et al., GCN 5921) Source 2, of: RA offset: +0.036s +/- 0.055s Dec offset: +0.13 +/- 0.8" and a new XRT astrometry corrected position of: RA(J2000): 09 38 05.24 Dec(J2000): +15 37 16.5 with an estimated uncertainty of 3.4 arcseconds (radius, 90% containment). This position is 1.1 arcseconds from the original refined XRT position of S2 given in Godet et al. (GCN 5921), and 2.6 arcseconds from the potential S2-G2 host galaxy described by Berger et al. (GCN 5922) and Mirabal et al. (GCN 5925) with z=0.41 (Cenko et al., GCN 5946). A figure comparing all of these positions is available at: http://www.swift.psu.edu/images/grb061210_astrometry.gif This circular is an official product of the Swift XRT team.