GRB150309A

This page lists all entries on GRB150309A in GRBweb

Summary Fermi GBM IPN Swift GCN 17553 GCN 17554 GCN 17555 GCN 17556 GCN 17557 GCN 17558 GCN 17559 GCN 17560 GCN 17561 GCN 17562 GCN 17564 GCN 17565 GCN 17566 GCN 17570

Summary table
Variable Value Source
GRB_name_Fermi GRB150309958
T0 22:59:50.658 UTC Fermi_GBM
ra 277.1020° Swift
decl 86.4289° Swift
pos_error 1.94e-04° Swift
T90 52.481 s Fermi_GBM
T90_error 1.086 s Fermi_GBM
T90_start 22:59:54.306 UTC Fermi_GBM
fluence 3.98e-05 erg/cm² Fermi_GBM
fluence_error 1.82e-07 erg/cm² Fermi_GBM
T100 437.342 s
GBM_located False
mjd 57090.958225208335 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB150309958
trigger_name bn150309958
ra 277.1021°
decl 86.4286°
pos_error 2.48e+00°
datum 2015-03-09
t_trigger 22:59:50.658 UTC
T90 52.481 s
T90_error 1.086 s
T90_start 22:59:54.306 UTC
fluence 3.98e-05 erg/cm²
fluence_error 1.82e-07 erg/cm²
flux_1024 1.52e+01 erg/cm²/s
flux_1024_error 3.05e-01 erg/cm²/s
flux_1024_time 1.75e+01 erg/cm²/s
flux_64 1.84e+01 erg/cm²/s
flux_64_error 1.29e+00 erg/cm²/s
IPN table
GRB_name GRB150309A
ra 276.9875°
decl 86.4333°
pos_error 5.00e-02°
Swift table
GRB_name GRB150309A
t_trigger 23:03:06 UTC
ra 277.1020°
decl 86.4289°
pos_error 1.94e-04°
T90 242.0 s
fluence 1.70e-05 erg/cm²
GCN 17553 table
GRB_name GRB150309A
GCN_number 17553
Detection_method Swift Det
t_trigger 23:03:06 UTC
ra 276.9870°
decl 86.4300°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17553 SUBJECT: GRB 150309A: Swift detection of a burst DATE: 15/03/09 23:17:18 GMT FROM: Scott Barthelmy at NASA/GSFC J. R. Cummings (NASA/UMBC), S. D. Barthelmy (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and T. N. Ukwatta (LANL) report on behalf of the Swift Team: At 23:03:06 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150309A (trigger=634200). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 276.987, +86.430, which is RA(J2000) = 18h 27m 57s Dec(J2000) = +86d 25' 46" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a peak around T+30 sec with a duration of about 60 sec. The peak count rate was ~200 counts/sec (15-350 keV), at ~45 sec after the trigger. The XRT began observing the field at 23:05:18.2 UT, 131.5 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 277.08842, 86.42988 which is equivalent to: RA(J2000) = 18h 28m 21.22s Dec(J2000) = +86d 25' 47.6" with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 22 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 in excess of the Galactic value (9.05 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.4 (+3.89/-3.10) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 2.73e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 140 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 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 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 0.14. Burst Advocate for this burst is J. R. Cummings (jayc AT milkyway.gsfc.nasa.gov). 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.)
GCN 17554 table
GRB_name GRB150309A
GCN_number 17554
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17554 SUBJECT: GRB 150309A: BOOTES-1 and -2 upper limit DATE: 15/03/10 00:13:17 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia R. Cunniffe, M. Jelinek, Y. Hu, S. Jeong, S. R. Oates (IAA-CSIC), B.-B. Zhang (IAA-CSIC and UAH) and A. J. Castro-Tirado (IAA-CSIC and ISA-UMA), on behalf of a larger collaboration, report: Both the 60 cm BOOTES-2/TELMA and the 30 cm BOOTES-1 robotic telescopes in South Spain automatically responded to the Swift trigger of GRB 150309A (Cummings et al., GCN 17553). The first exposure started at 23:04:33 UT (86s after the trigger) and a sequence of 20 images was obtained (3s each, clear filter). A median combined image revealed no optical counterpart at the enhanced XRT error circle down to 18 mag. Further observations are ongoing. [GCN OPS NOTE(10mar15): Per author's request, the affilliation of B-BZ was changed.]
GCN 17555 table
GRB_name GRB150309A
GCN_number 17555
Detection_method Swift-XRT Det
ra 277.1021°
decl 86.4287°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17555 SUBJECT: GRB 150309A: Enhanced Swift-XRT position DATE: 15/03/10 09:14:30 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 853 s of XRT Photon Counting mode data and 2 UVOT images for GRB 150309A, 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 = 277.10213, +86.42875 which is equivalent to: RA (J2000): 18h 28m 24.51s Dec (J2000): +86d 25' 43.5" with an uncertainty of 1.5 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.
GCN 17556 table
GRB_name GRB150309A
GCN_number 17556
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17556 SUBJECT: GRB 150309A : Liverpool Telescope observations DATE: 15/03/10 11:07:36 GMT FROM: Andrea Melandri at INAF-OAB A. Melandri (INAF-OAB), D. Kopac (LJMU), R. J. Smith (LJMU), C. G. Mundell (U. Bath) and A. Gomboc (U. Ljubljana), on behalf of a large collaboration report: The 2-m Liverpool Telescope robotically followed up Swift GRB 150309A (Cummings et al., GCN 17553) at 23:06:37 UT (~3.5 min after the burst trigger). No optical counterpart is detected at the enhanced XRT error circle (Osborne et al., GCN 17555) down to r > 19.5 mag (~37 min after burst).
GCN 17557 table
GRB_name GRB150309A
GCN_number 17557
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17557 SUBJECT: GRB 150309A: Swift-XRT refined Analysis DATE: 15/03/10 11:17:03 GMT FROM: Phil Evans at U of Leicester J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), M. de Pasquale (INAF-IASFPA), D.N. Burrows (PSU) and J.R. Cummings report on behalf of the Swift-XRT team: We have analysed 6.9 ks of XRT data for GRB 150309A (Cummings et al. GCN Circ. 17553), from 122 s to 17.9 ks after the BAT trigger. The data comprise 273 s in Windowed Timing (WT) mode (the first 8 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 17555). The light curve can be modelled with an initial power-law decay with an index of alpha=2.11 (+0.09, -0.07), followed by a break at T+477 s to an alpha of 0.98 (+/-0.04). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.82 (+/-0.07). The best-fitting absorption column is 2.03 (+0.28, -0.27) x 10^21 cm^-2, in excess of the Galactic value of 9.1 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.91 (+0.12, -0.11) and a best-fitting absorption column of 2.8 (+/-0.5) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (5.4 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.8 (+/-0.5) x 10^21 cm^-2 Galactic foreground: 9.1 x 10^20 cm^-2 Excess significance: 6.6 sigma Photon index: 1.91 (+0.12, -0.11) If the light curve continues to decay with a power-law decay index of 0.98, the count rate at T+24 hours will be 0.022 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.4 x 10^-13 (1.2 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00634200. This circular is an official product of the Swift-XRT team.
GCN 17558 table
GRB_name GRB150309A
GCN_number 17558
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17558 SUBJECT: GRB 150309A: MASTER prompt optical observation DATE: 15/03/10 11:53:50 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D.Kuvshinov, V.Kornilov, Lomonosov Moscow State University, Sternberg Astronomical Institute A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk V.Krushinsky, Ural Federal University, Yekaterinburg, Kourovka 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 ( Lipunov et al., Advances in Astronomy, vol. 2010, pp. 1-7, MASTER Global Robotic Net, 2010) located in Kislovodsk was pointed to the GRB150309A 21 sec after notice time and 96 sec after trigger time at 2015-03-09 23:04:45 UT in two polarizations. On our first (20s exposure) set we not found optical transient within SWIFT error-box (Cummings et al GCN 17553) brighter then 17.2 Before this, the MASTER serial pointed to FERMI (trig. N 447634793) coordinates. Due to this pointings we have a two images from MASTER VWF very wide fild camera obtained at 2015-03-09 23:00:34 i.e. 152 sec before SWIFT BAT and 44 sec after FERMI GBM trigger times. We not found new OT on this 5 sec exposure images with upper limit 12.0 at SWIFT position. Table 1. GRB 150309A MASTER optical upper limits. Tstart Tst-T0 Tmid-T0 Expt Mlimit Instrum. Coadd. 23:00:34 -152 -149 5 12.0 MASTER VWF no 23:04:45 98 108 20 17.2 MASTER II no 23:04:45 98 559 780 19.3 MASTER II 10 23:20:20 1033 2363 2160 20.0 MASTER II 12 T0 - is a SWIFT trigger time. The message may be cited.
GCN 17559 table
GRB_name GRB150309A
GCN_number 17559
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17559 SUBJECT: GRB 150309A: Swift/UVOT Upper Limits DATE: 15/03/10 13:16:03 GMT FROM: Samantha Oates at MSSL S. R. Oates (IAA-CSIC/UCL-MSSL) and J. R. Cummings (NASA/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 150309A 140 s after the BAT trigger (Cummings et al., GCN Circ. 17553). No optical afterglow consistent with the XRT position (Osborne et al. GCN Circ. 17555) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 140 290 147 >20.3 u_FC 299 549 246 >19.4 white 140 12463 881 >21.1 v 630 6293 432 >19.3 b 555 12046 1121 >20.8 u 299 17720 2241 >21.1 w1 679 16806 1318 >20.8 m2 654 6498 432 >20.1 w2 605 6089 432 >20.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.14 in the direction of the burst (Schlegel et al. 1998).
GCN 17560 table
GRB_name GRB150309A
GCN_number 17560
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17560 SUBJECT: GRB150309A: Optical observations at Crni Vrh DATE: 15/03/10 14:27:29 GMT FROM: Herman Mikuz at OCV B. Dintinjana, S. Maticic and H. Mikuz on behalf of PIKA observing program at Crni Vrh Observatory. We observed the field of GRB 150309A (Cummings et al., GCN 17553) from Crni Vrh Observatory with a 60 cm robotic telescope and clear filter. Twenty six consecutive exposures of 60 second duration were taken in moonlight conditions. First exposure started at 2015-03-09 23:05:34 UT, 68 seconds after the SWIFT trigger. No optical candidate was detected within the uncertainty radius on single exposures, having limiting magnitude 19.2, calibrated against the nerby USNO-B R2 magnitude stars. Also we found no optical candidate on 26 sumed unfiltered images with total exposure of 1560 seconds and limiting magnitude 20.8 (calibrated against the nerby USNO-B R2 magnitude stars).
GCN 17561 table
GRB_name GRB150309A
GCN_number 17561
Detection_method Fermi GBM Det
t_trigger 22:59:50.660 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 17561 SUBJECT: GRB 150309A: Fermi GBM detection DATE: 15/03/10 15:13:46 GMT FROM: Oliver Roberts at UCD/Fermi O.J Roberts (UCD) and M. Stanbro (UAH) report on behalf of the Fermi GBM Team: "At 22:59:50.66 UT on the 9th of March 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150309A (trigger 447634793/150309958), the second episode of which was also detected by Swift (Cummings et al. 2015, GCN 17553). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 60 degrees. The Swift trigger is observed in the GBM light curve at T0+200 s as a very soft, weak event with a duration of about 60 s. The immediate light curve at the GBM trigger time consists of a bright, main peak of unresolved emission episodes, with a duration (T90) of about 52 s (50-300 keV). The time-averaged spectrum from T0+0.0 s to T0+52.6 s is best fit by a Band function with Epeak= 165 +/- 4 keV, alpha = -0.59 +/- 0.02 and beta = -2.59 +/- 0.10. The event fluence (10-1000 keV) in this time interval is (3.9 +/- 0.1)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+17.5 s in the 10-1000 keV band is 15.2 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 17562 table
GRB_name GRB150309A
GCN_number 17562
Detection_method Swift-BAT Det
ra 277.0040°
decl 86.4170°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17562 SUBJECT: GRB 150309A: Swift-BAT refined analysis DATE: 15/03/10 19:58:42 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), 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-239 to T+471 sec from the recent telemetry downlink, we report further analysis of BAT GRB 150309A (trigger #634200) (Cummings, et al., GCN Circ. 17553). The BAT ground-calculated position is RA, Dec = 277.004, 86.417 deg which is RA(J2000) = 18h 28m 01.0s Dec(J2000) = +86d 25' 02.7" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 50%. The mask-weighted light curve shows that the main peak of the burst, which occurred during a Swift preplanned slew maneuver, started at about T-200 seconds. The roughly symmetrical peak with multiple maxima lasted until about T-160 seconds. A weaker overlapping peak followed at about T-150 seconds and declined to background by about T-60 seconds. BAT triggered on a smaller peak that lasted from about T+0 seconds to about T+120 seconds. T90 (15-350 keV) is 242 +- 6 sec (estimated error including systematics). Because the source came into the BAT field of view during the slew, it is possible that there was some additional low-level emission before T-200 seconds. The time-averaged spectrum from T-197.32 to T+119.08 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.05 +- 0.16, and Epeak of 175.8 +- 76.0 keV (chi squared 37.47 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 1.7 +- 0.0 x 10^-05 erg/cm2 and the 1-sec peak flux measured from T-177.49 sec in the 15-150 keV band is 9.0 +- 0.3 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.36 +- 0.04 (chi squared 49.55 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/634200/BA/
GCN 17564 table
GRB_name GRB150309A
GCN_number 17564
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17564 SUBJECT: GRB 150309A: ISON-Kislovodsk optic upper limit DATE: 15/03/11 12:35:27 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Vazaeva (IKI), V. Nevskiy (ISON), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI),report on behalf of larger collaboration: We observed the field of the Swift GRB 150309A (Cummings et al., GCN 17553) with Santel-400AN telescope of ISON-Kislovodsk observatory starting on Mar. 09 (UT) 23:11:26, i.e. ~8.5 min after the burst trigger. In the enhanced XRT position (Osborne et al., GCN 17555) we do not detect any object. An upper limit is following Date UT start t-T0 Filter Exp. UL(3 sigma) (mid, days) (s) 2014-09-03 23:11:26 0.02590 None 49*60 20.0 The photometry is based on USNO-B1.0 star USNO-B1.0_id R2 1764-0030460 15.42
GCN 17565 table
GRB_name GRB150309A
GCN_number 17565
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17565 SUBJECT: GRB 150309A: CrAO optic upper limit DATE: 15/03/11 12:55:33 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), K. Antoniuk, E. Mazaeva (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 150309A (Cummings et al., GCN 17553) with AZT-11 telescope of CrAO observatory starting on Mar. 09 (UT) 23:39:47. We took several images in R-filter of 180 s exposure. In the enhanced XRT position (Osborne et al., GCN 17555) we do not detect any object. An upper limit is following Date UT start, t-t0 Filter Exp. UL (3 sigma) (mid, days) (s) 2015-03-09 23:39:47 0.0468 R 20*180 20.9 The photometry is based on nearby USNO-B1.0 stars.
GCN 17566 table
GRB_name GRB150309A
GCN_number 17566
Detection_method Konus-Wind Det
t_trigger 22:59:52.708 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 17566 SUBJECT: Konus-Wind observation of GRB 150309A DATE: 15/03/11 13:08:42 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 150309A (Swift-BAT trigger #634200: Cummings et al., GCN 17553; Baumgartner et al., GCN 17562) triggered Konus-Wind at T0=82792.708 s UT (22:59:52.708). The KW light curve shows a broad emission pulse which starts at ~T0-7 s and decays to ~T0+55 s. The pulse is followed by a weak soft emission detectable up to ~T0+250 s. The emission is visible up to ~4 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB150309_T82792/ As observed by Konus-Wind, the burst had a fluence of 4.1(-0.4,+0.5)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+16.832 s, of 4.0(-0.4,+0.4)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+53.248 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.79 (-0.09,+0.11), the high energy photon index beta = -2.79 (-0.48,+0.29), the peak energy Ep = 182 (-17,+14) keV, chi2 = 101/97 dof. The spectrum near the peak count rate (measured from T0+8.448 to T0+20.480 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.64 (-0.09,+0.11), the high energy photon index beta = -2.73 (-0.34,+0.22), the peak energy Ep = 197 (-17,+16) keV, chi2 = 110/97 dof. All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN 17570 table
GRB_name GRB150309A
GCN_number 17570
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17570 SUBJECT: GRB 150309A: AAO optic upper limit DATE: 15/03/12 18:16:20 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), R. Inasaridze (AAO), Sh. Makandarashvili (AAO), A. Volnova (IKI), Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 150309A (Cummings et al., GCN 17553) with AS-32 (0.7m) telescope of Abastumani Observatory starting on Mar. 10 (UT) 01:40:54. Within the enhanced XRT position (Osborne et al., GCN 17555) we do not detect any object. An upper limit is following Date UT start t-T0 Filter Exp. UL(3 sigma) (mid, days) (s) 2015-03-10 01:40:54 0.12699 None 19*120 21.2 The photometry is based on USNO-B1.0 star USNO-B1.0_id R2 1764-0030460 15.42