//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17464 SUBJECT: GRB 150213B: Swift detection of a burst with an optical afterglow DATE: 15/02/13 22:47:24 GMT FROM: Scott Barthelmy at NASA/GSFC C. Pagani (U Leicester), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), C. J. Mountford (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 22:31:30 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150213B (trigger=631051). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 253.425, +34.179 which is RA(J2000) = 16h 53m 42s Dec(J2000) = +34d 10' 43" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is typical for image triggers (64 sec), the realtime TDRSS light curve does not show anything significant. The XRT began observing the field at 22:33:54.1 UT, 143.3 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 253.4532, 34.1886 which is equivalent to: RA(J2000) = +16h 53m 48.77s Dec(J2000) = +34d 11' 19.0" with an uncertainty of 5.0 arcseconds (radius, 90% containment). This location is 90 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. The initial flux in the 2.5 s image was 2.84e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 152 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 16:53:48.65 = 253.45271 DEC(J2000) = +34:11:19.4 = 34.18872 with a 90%-confidence error radius of about 0.63 arc sec. This position is 1.5 arc sec. from the center of the XRT error circle. The estimated magnitude is 18.46 with a 1-sigma error of about 0.15. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02. Burst Advocate for this burst is C. Pagani (cp232 AT star.le.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17465 SUBJECT: GRB 150213B: Tautenburg Afterglow Detection DATE: 15/02/14 01:22:21 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann, B. Stecklum, and F. Ludwig (TLS Tautenburg) report: We began observations of GRB 150213B (Swift trigger 631051, Pagani et al., GCN 17464) with the 1.34m Tautenburg Schmidt telescope about 80 min after the GRB, at airmass 2.9. At the UVOT position given by Pagani et al., we detect the optical afterglow in multiple Rc band exposures of 600 sec exposure time each. Due to the PSF wings of a nearby bright star, no magnitude can be determined at this time, but the source has clearly faded compared to the early Swift detection. Observations are ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17467 SUBJECT: GRB 150213B: optical detection from the NOT DATE: 15/02/14 06:11:29 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani (DARK/NBI), D. Xu (DARK/NBI), A. de Ugarte Postigo (IAA/CSIC and DARK/NBI), P. Jakobsson (Univ. Iceland), and J. Telting (NOT) report on behalf of a larger collaboration: We observed the field of GRB 150213B (Pagani et al., GCN 17464) with the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations started on Feb 14.22 UT (6.86 hr after the GRB), and consisted of 4x300 s exposures in the SDSS r filter. The optical afterglow (Pagani et al., GCN 17464; Kann et al., GCN 17465) is well detected in our images. A preliminary analysis yields a magnitude r = 22.10 +- 0.05 (AB), calibrated against nearby SDSS stars. [GCN OPS NOTE(14feb15): Per author's request, DX was added to the author list.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17468 SUBJECT: GRB 150213B: AAO optical observations DATE: 15/02/14 07:06:15 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), R. Inasaridze (AAO), E. Mazaeva (IKI), A. Volnova (IKI), Molotov (KIAM), report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 150213B (Pagani et al., GCN 17464) with AS-32 (0.7m) telescope of Abastumani Observatory. We obtained several unfiltered images starting on Feb. 13 (UT) 23:24:58 and ending Feb. 14 (UT) 01:06:30. In the first single images of 120 s exposure we clearly detect the optical afterglow (Pagani et al., GCN 17464; Kann et al., GCN 17465; Malesani et al., GCN 17467). Preliminary photometry of the afterglow is 19.7m (at 54 minutes after burst trigger) in comparison with nearby USNO-B1.0 stars (R2 mags). Data receiving and reduction is ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17469 SUBJECT: GRB 150213B: Swift-XRT refined Analysis DATE: 15/02/14 10:47:06 GMT FROM: Phil Evans at U of Leicester J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU) and C. Pagani report on behalf of the Swift-XRT team: We have analysed 8.5 ks of XRT data for GRB 150213B (Pagani et al. GCN Circ. 17464), from 133 s to 23.5 ks after the BAT trigger. The data comprise 414 s in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 253.4520, +34.1884 which is equivalent to: RA (J2000): 16 53 48.49 Dec(J2000): +34 11 18.4 with an uncertainty of 3.6 arcsec (radius, 90% confidence). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=1.18 (+0.09, -0.10). At T+310 s the decay steepens to an alpha of 2.46 (+0.26, -0.23) before breaking again at T+2218 s to a final decay with index alpha=1.33 (+0.24, -0.21). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.86 (+0.05, -0.04). The best-fitting absorption column is 5.1 (+/-1.0) x 10^20 cm^-2, in excess of the Galactic value of 1.9 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.74 (+0.29, -0.26) and a best-fitting absorption column of 6.7 (+7.9, -4.8) x 10^20 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.7 x 10^-11 (4.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 6.7 (+7.9, -4.8) x 10^20 cm^-2 Galactic foreground: 1.9 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 1.74 (+0.29, -0.26) If the light curve continues to decay with a power-law decay index of 1.33, the count rate at T+24 hours will be 1.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.9 x 10^-14 (6.6 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00631051. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17470 SUBJECT: GRB 150213B: RATIR Optical and NIR Observations DATE: 15/02/14 15:42:07 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 150213B (Pagani, et al., GCN 17464) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2015/02 14.41 to 2015/02 14.55 UTC (11.27 to 14.72 hours after the BAT trigger), obtaining a total of 2.58 hours exposure in the r, i, and z bands. For a source within the Swift-UVOT error circle, in comparison with the SDSS DR9, we obtain the following detections and upper limit (3-sigma): r = 22.4 +/- 0.6 i = 22.1 +/- 0.1 z > 20.50 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17471 SUBJECT: GRB 150213B: Swift-BAT refined analysis DATE: 15/02/14 16:02:52 GMT FROM: Scott Barthelmy at NASA/GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), C. Pagani (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 150213B (trigger #631051) (Pagani, et al., GCN Circ. 17464). The BAT ground-calculated position is RA, Dec = 253.448, 34.165 deg, which is RA(J2000) = 16h 53m 47.4s Dec(J2000) = +34d 09' 54.5" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 13%. The mask-weighted light curve shows a FRED peak with a few little peaks starting at ~T+0, peaking at ~T+18, and returning to baseline at ~T+300 sec. T90 (15-350 keV) is 181 +- 60 sec (estimated error including systematics). The time-averaged spectrum from T+2.09 to T+249.78 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.80 +- 0.79, and Epeak of 54.8 +- 20.6 keV (chi squared 57.4 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 3.0 +- 0.4 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+18.08 sec in the 15-150 keV band is 1.1 +- 0.4 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.77 +- 0.15 (chi squared 63.4 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/631051/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17472 SUBJECT: GRB 150213B: Swift/UVOT Detection DATE: 15/02/14 18:21:33 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and C. Pagani (U. Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 150213B 153 s after the BAT trigger (Pagani et al., GCN Circ. 17464). A source consistent with the XRT position (Osborne et al. GCN Circ. 17469) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 16:53:48.67 = 253.45278 (deg.) Dec (J2000) = +34:11:19.3 = 34.18869 (deg.) with an estimated uncertainty of 0.46 arc sec. (radius, 90% confidence). Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 153 302 147 18.61 +/- 0.07 v 4498 23548 966 >20.3 b 3883 12039 961 >20.7 u 310 532 218 18.76 +/- 0.15 w1 4910 10539 1082 20.76 +/- 0.21 m2 4703 16622 1224 21.25 +/- 0.32 w2 4293 22956 1279 21.48 +/- 0.31 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17474 SUBJECT: GRB 150213B: P60 Observations DATE: 15/02/14 20:16:02 GMT FROM: S. Bradley Cenko at NASA/GSFC S. B. Cenko (NASA/GSFC) and D. A. Perley (Caltech) report on behalf of a larger collaboration: We have imaged the location of GRB150213B (Pagani et al., GCN 17464) with the robotic Palomar 60 inch telescope. Observations began at 10:15 UT on 2015 Feb 14 (dt ~ 11.7 hr after the Swift trigger) and were obtained in the SDSS g, r, i, and z filters. We marginally detect the optical afterglow (Kann et al., GCN 17465; Malesani et al., GCN 17467; Pozanenko et al., GCN 17468; Butler et al., GCN 17470). Using nearby point sources from SDSS for reference, we measure an r-band magnitude of r' = 22.65 +/- 0.33 - however we caution that the photometry is likely affected by the presence of the nearby bright star (e.g., Kann et al., GCN 17465). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17475 SUBJECT: GRB 150213B: Enhanced Swift-XRT position DATE: 15/02/16 07:39:45 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 5563 s of XRT Photon Counting mode data and 8 UVOT images for GRB 150213B, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 253.45234, +34.18876 which is equivalent to: RA (J2000): 16h 53m 48.56s Dec (J2000): +34d 11' 19.5" with an uncertainty of 1.6 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17478 SUBJECT: GRB 150213B: AAO photometry DATE: 15/02/19 16:49:54 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), A. Pozanenko (IKI), E. Mazaeva (IKI), R. Inasaridze (AAO), Sh. Makandarashvili (AAO), Molotov (KIAM), report on behalf of larger GRB follow-up collaboration: We report photometry of our observation (GCN 17468) of the field of the Swift GRB 150213B (Pagani et al., GCN 17464) with AS-32 (0.7m) telescope of Abastumani Observatory. The optical afterglow (Pagani et al., GCN 17464; Kann et al., GCN 17465; Malesani et al., GCN 17467) is visible on single images. The photometry of the afterglow is following Date UT start t-T0 Filter Exp. OT Err. (mid, days) (s) 2015-02-13 23:22:23 0.03696 none 2*120 18.98 0.14 2015-02-13 23:27:43 0.04345 none 5*120 19.15 0.10 2015-02-13 23:41:05 0.05273 none 5*120 19.56 0.13 2015-02-13 23:54:27 0.06201 none 5*120 19.12 0.13 2015-02-13 24:07:49 0.07593 none 10*120 19.12 0.06 2015-02-13 24:34:32 0.09634 none 12*120 19.20 0.08 The photometry might be affected by the presence of the nearby bright star (e.g., Kann et al., GCN 17465). The photometry is based on nearby SDSS DR9 stars: SDSS9_id R(Lupton) J165343,83+341043,0 16,49 J165348,15+341040,4 15,99 J165354,27+341137,8 17,87 J165339,38+341103,1 17,14 J165341,19+341135,8 14,53 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17484 SUBJECT: GRB 150213B, the review of the sky area in plate archives DATE: 15/02/21 16:24:17 GMT FROM: Valentyna Golovnya at Main Astro Obs,Kyiv V.V. Golovnya (Main Astro Obs., Kyiv) report: We have undertaken the review of the sky area of GRB 150213B (J.P. Osborne et al. GCN Circ. 17475) on astronegatives, collected in Ukrainian plate archive (1976-1996). All the plates with the possible object appearance are digitized using Epson Expression 10000XL flatbed scanner and the images have been placed into Golosiiv Plate Archive database DBGPA with open access to them. The list of plates is given in the table: yyyymmdd/TimeUT ---Plates----- Exp. -Mag- --USNO-B1-- 19770616/20:26:55 GUA040C000526B 60.1 17.26 1241-0248873 19770622/20:59:18 GUA040C000533B 60.0 17.26 1241-0248873 19770707/20:05:18 GUA040D000569A 29.7 17.20 1241-0248872 19770713/20:16:28 GUA040C000578B 30.0 17.20 1241-0248872 19770713/20:16:29 GUA040D000579 30.0 17.20 1241-0248872 Plates -the plates archive identifier of DWA D/F=400/2000, M=103"/mm (Marsden's number - 083) the plate number [1]. Exp. - Duration of the maximum exposures (minutes). Mag - Limited Bmag, derived in the 9 minutes area around the location given in J.P. Osborne et al. GCN Circ. 17475: RA(J2000): 16h 53m 48.56s, Dec(J2000): +34d 11' 19.5". USNO-B1 - Comparison star. The preview images of 5 areas together with the 9 min. of arc area from Aladin can be found in “http://gua.db.ukr-vo.org/img/grb/150213B/index.htmlâ€. The images with full resolution are available via e-mail on demand. References: 1.L.Pakuliak DATABASE of GOLOSIIV PLATE ARCHIVE (DBGPA V2.0), “http://gua.db.ukr-vo.orgâ€.