//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17449 SUBJECT: GRB 150212A: Swift detection of a burst DATE: 15/02/12 11:19:00 GMT FROM: Scott Barthelmy at NASA/GSFC K. L. Page (U Leicester), A. Amaral-Rogers (U Leicester), S. D. Barthelmy (GSFC), M. M. Chester (PSU), P. A. Evans (U Leicester), F. E. Marshall (NASA/GSFC), C. J. Mountford (U Leicester) and P. T. O'Brien (U Leicester) report on behalf of the Swift Team: At 10:57:19 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150212A (trigger=630876). The Swift slew was delayed by 4.7 min due to an observing constraint. The BAT on-board calculated location is RA, Dec 285.521, +47.407 which is RA(J2000) = 19h 02m 05s Dec(J2000) = +47d 24' 27" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single FRED peak with a duration of about 10 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~1 sec after the trigger. Due to an observing constraint, Swift did not slew until T0+4.7 minutes. By this time Swift had entered the South Atlantic Anomaly, from which it will emerge at 11:26 UT. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is K. L. Page (kpa 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: 17451 SUBJECT: GRB150212A: P60 Afterglow Candidate DATE: 15/02/12 11:47:36 GMT FROM: S. Bradley Cenko at NASA/GSFC S. B. Cenko (NASA/GSFC) reports on behalf of a larger collaboration: We have imaged the field of the Swift GRB150212A (Page et al., GCN 17449) with the robotic Palomar 60 inch telescope. Observations were obtained in the Sloan riz filters beginning at 11:12 UT (~ 15 min after the Swift trigger). We identify a bright source in the BAT error circle not present in archival DSS imaging of the field in all 3 filters: RA: 19:01:53.92 Dec: +47:26:10.7 We measure a preliminary magnitude of r = 16.8 at ~ 15 min after the Swift trigger (calibration performed with respect to nearby point sources from the APASS catalog). While we have not yet confirmed fading, we consider this source to be the likely optical afterglow of GRB150212A. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17452 SUBJECT: GRB 150212A: Swift-XRT afterglow detection DATE: 15/02/12 11:58:35 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: The XRT began observing the field at 11:03:12.7 UT, 353.7 seconds after the BAT trigger. Due to passage of the spacecraft through the South Atlantic Anomaly, no XRT data were collected until T0+1805 s. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 285.48092, 47.36602 which is equivalent to: RA(J2000) = 19h 01m 55.42s Dec(J2000) = +47d 21' 57.7" with an uncertainty of 4.3 arcseconds (radius, 90% containment). This location is 176 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 5.20 x 10^20 cm^-2 (Willingale et al. 2013). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17454 SUBJECT: GRB 150212A: P60 Afterglow Retraction DATE: 15/02/12 12:22:19 GMT FROM: S. Bradley Cenko at NASA/GSFC S. B. Cenko (NASA/GSFC) reports on behalf of a larger collaboration: We have obtained further imaging of the field the Swift GRB 150212A (Page et al., 17449) with the robotic Palomar 60 inch telescope. The candidate afterglow we previously identified (GCN 17451) has remained at a constant brightness over the course of the last hour, and is well offset from the candidate XRT afterglow (Evans et al., GCN 17452). Further inspection of archival catalogs indicates this object is likely to be a high proper motion star. We apologize for any inconvenience this may have caused. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17455 SUBJECT: GRB 150212A: No Swift/UVOT detection in initial observation DATE: 15/02/12 12:30:39 GMT FROM: Margaret Chester at PSU M. M. Chester (Penn State), K. L. Page (U Leicester), and A. Amaral-Rogers (U Leicester) report on behalf of the Swift/UVOT team: UVOT took a finding chart exposure of 150 seconds with the White filter starting 1811 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers none of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.06. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17456 SUBJECT: GRB 150212A: MASTER optical observations DATE: 15/02/12 13:22:42 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University E. Gorbovskoy, V. Lipunov, M.Pruzhinskaya, V.Kornilov, D.Kuvshinov, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, D.Denisenko, A.Sankovich Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinsky, I.Zalozhnih, A. Popov Ural Federal University, Yekaterinburg, Kourovka D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA) MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka was pointed to the GRB150212A (Page et. al. GCN 17449) 32 sec after notice time and 47 sec after trigger time at 2015-02-12 10:58:06 UT in two polarization. Unfortunately we were unable to obtain satisfactory data on the first images due to clouds and high zenith distance (z~75 d). In the process of further observations we do not see the optical transient and obtained the following upper limits: T_start T-Tmid Expt. Mlimit 11:08:50 761 140 11.5 11:11:52 958 170 11.5 11:15:26 1177 180 12.5 11:26:34 1845 180 12.6 11:32:12 2183 180 15.0 11:32:12 3447 1800 16.7 11:35:58 2641 540 16.1 So weak upper limits associated with the observation through clouds and large zenith distance of the object. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17457 SUBJECT: GRB 150212A: Swift-BAT refined analysis DATE: 15/02/12 14:28:38 GMT FROM: Scott Barthelmy at NASA/GSFC J. R. Cummings (GSFC/UMBC), A. Amaral-Rogers (U Leicester), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), 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-60 to T+243 sec from recent telemetry downlinks, we report further analysis of BAT GRB 150212A (trigger #630876) (Page, et al., GCN Circ. 17449). The BAT ground-calculated position is RA, Dec = 285.497, 47.389 deg, which is RA(J2000) = 19h 01m 59.2s Dec(J2000) = +47d 23' 19.1" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 71%. The mask-weighted light curve is FRED peak starting at ~T-1 sec, peaking at ~T+1 sec, and ending at ~T+25 sec. T90 (15-350 keV) is 11.4 +- 4.1 sec (estimated error including systematics). The time-averaged spectrum from T-0.20 to T+19.66 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.50 +- 0.11. The fluence in the 15-150 keV band is 8.9 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.82 sec in the 15-150 keV band is 1.9 +- 0.2 ph/cm2/sec. 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/630876/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17458 SUBJECT: GRB 150212A: Skynet DSO14/GORT observations DATE: 15/02/12 20:27:47 GMT FROM: Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet A. Trotter, D. Reichart, A. LaCluyze, J. Haislip, A. Smith, D. Caton, L. Hawkins, K. McLin, L. Cominsky, A. Aji, T. Berger, A. Dow, A. Foster, N. Frank, K. Ivarsen, M. Maples, J. Moore, M. Nysewander, C. Salemi, and J. A. Crain report: Skynet observed the Swift BAT/XRT localization of GRB 150212A (Page et al., GCN 17449, Swift trigger=630876) with the 14" telescope at the Appalachian State University Dark Sky Observatory (DSO14) in NC, USA, and with the 14" GLAST Optical Robotic Telescope (GORT) at the Hume Observatory in CA, USA. DSO14 obtained exposures of the field starting at 2015-02-12 10:58:05 (t=46s post-trigger); GORT was delayed until 48m post-trigger due to clouds. Skynet took a total of 29 exposures ranging from 5s to 160s in the R and I bands. We do not detect any optical source at the XRT afterglow position reported by Evans (GCN 17452). Our early-time DSO14 limiting magnitudes are: ============================================== tmid scope band exposures lim mag ---------------------------------------------- 48s DSO14 I 1 x 5s >15.2 102s DSO14 I 2 x 10s >16.4 108s DSO14 R 1 x 5s >16.0 ============================================== Stacked subsets of those images that maximize the S/N ratio give limiting magnitudes: ============================================== tmid scope band exposures lim mag ---------------------------------------------- 15.4m DSO14 R 1 x 80s >18.4 1 x 160s 16.1m DSO14 I 1 x 80s >18.4 1 x 160s 74m GORT R 4 x 160s >17.2 84m GORT I 3 x 160s >16.8 ============================================== Magnitudes are in the Vega System, calibrated to 10 APASS stars in the field. Magnitudes have not been corrected for line-of-sight Milky Way dust extinction, with expected E(B-V)=0.051 (Schlafly & Finkbeiner 2011). No further Skynet observations are scheduled. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17459 SUBJECT: GRB 150212A: Khureltogot optical upper limit DATE: 15/02/12 20:37:01 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), S. Schmalz (AIP), N. Tungalag (Research Center of Astronomy and Geophysics MAS), A. Volnova (IKI), I.Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of 150212A (Page et al., GCN 17449) with ORI-40 telescope of Khureltogot observatory on Feb., 12 starting on (UT) 11:32:28. We obtained 24 unfiltered images of 15 s exposure. We did not detect any optical counterpart in XRT error circle (Evans et al. GCN 17452). Details of the photometry are following: Date UT start t-T0 Filter Exp. uplim (3 sigma) (mid, days) (s) 2015-02-12 11:32:28 0.02739 none 24*15 15.8 The star mentioned by Cenko et al. (GCNs 17451, 17454) is visible in our combined image and have a brightness of 15.85 +/- 0.25. The photometry is based on R magnitudes of nearby USNO-B1.0 stars USNO-B1_id R2 1374-0373548 15.39 1374-0373502 14.41 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17460 SUBJECT: GRB 150212A: RATIR Optical and NIR Observations DATE: 15/02/12 22:41:55 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 150212A (Page, et al., GCN 17449) 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 12.51 to 2015/02 12.55 UTC (1.29 to 2.31 hours after the BAT trigger), obtaining a total of 0.89 hours exposure in the r, i, and z bands. We find one uncatalogued source within the Swift XRT error circle (Evans, et al., GCN 17452) at a position RA, Dec = 285.48273, 47.36637 (+/- 0.5", J2000) with magnitudes r = 23.1 +/- 0.4 and i = 21.4 +/- 0.1. This source does not appear to fade in time during our observation. For other potential sources within the XRT error circle, in comparison with USNO-B1 and 2MASS, we obtain the following upper limits (3-sigma): r > 23.1 i > 23.3 z > 19.6 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: 17462 SUBJECT: GRB 150212A: Swift-XRT refined Analysis DATE: 15/02/13 08:30:07 GMT FROM: Alex Amaral-Rogers at U.of Leicester A. Amaral-Rogers (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), M. de Pasquale (INAF-IASFPA), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), D.N. Burrows (PSU), J.A. Kennea (PSU) and K. L. Page (U Leicester) report on behalf of the Swift-XRT team: We have analysed 4.1 ks of XRT data for GRB 150212A (Page et al. GCN Circ. 17449), from 1.8 ks to 54.6 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 285.4799, +47.3656 which is equivalent to: RA (J2000): 19 01 55.16 Dec(J2000): +47 21 56.3 with an uncertainty of 3.7 arcsec (radius, 90% confidence). The light curve can be modelled with a power-law decay with a decay index of alpha=0.56 (+0.15, -0.14). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.3 (+/-0.4). The best-fitting absorption column is 1.7 (+1.2, -1.0) x 10^21 cm^-2, in excess of the Galactic value of 5.2 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.0 x 10^-11 (4.4 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.7 (+1.2, -1.0) x 10^21 cm^-2 Galactic foreground: 5.2 x 10^20 cm^-2 Excess significance: 2.0 sigma Photon index: 2.3 (+/-0.4) If the light curve continues to decay with a power-law decay index of 0.56, the count rate at T+24 hours will be 0.012 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.5 x 10^-13 (5.2 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00630876. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17466 SUBJECT: GRB 150212A: Swift/UVOT Observations DATE: 15/02/14 01:30:43 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel, M. M. Chester (PSU), A. Amaral-Rogers (U Leicester) and D. Malesani (DARK/NBI) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 150212A 1812 s after the BAT trigger (Page et al. GCN Circ. 17449; Chester et al. GCN Circ. 17455). A cataloged optical source is detected within the XRT error circle (Evans GCN Circ. 17452). The measured magnitudes are consistent with the cataloged values and no fading is evident. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17473 SUBJECT: GRB 150212A, the review of the sky area in plate archives DATE: 15/02/14 18:49:48 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 150212A (P.A. Evans GCN Circ. 17452) 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-- 19840720/21:19:40 GUA040C000430A 22.5 15.93 1373-0374987 19770622/22:14:06 GUA040C000535B 60.0 17.17 1374-0373547 19860716/21:18:54 GUA040C000961 16.0 17.42 1373-0374984 19870701/22:16:16 GUA040C001064 16.0 17.42 1373-0374984 19870822/19:11:46 GUA040C001078A 16.0 16.33 1373-0374866 Plates:–the plates archive identifier of DWA D/F=400/2000, M=103"/mm (Marsden's number - 83) the plate number [1]. Exp. - Duration of the maximum exposures (minutes). Mag - Limited Bmag, derived in the 7 minutes area around the location given in Evans GCN Circ. 17452: RA(J2000): 19h 01m 55.27s, Dec(J2000): +47d 21' 57.6". USNO-B1 - Comparison star. The preview images of 5 areas together with the 7 min. of arc area from Aladin can be found in "http://gua.db.ukr-vo.org/img/grb/150212A/index.html". 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.org".