//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14293 SUBJECT: GRB 130313A: Swift detection of a short burst DATE: 13/03/13 16:36:56 GMT FROM: Scott Barthelmy at NASA/GSFC B.P. Gompertz (U Leicester), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), V. D'Elia (ASDC), S. T. Holland (STScI), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), M. H. Siegel (PSU), R. L. C. Starling (U Leicester), C. A. Swenson (PSU) and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift Team: At 16:08:11 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130313A (trigger=550906). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 236.423, -0.362 which is RA(J2000) = 15h 45m 42s Dec(J2000) = -00d 21' 41" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single spike with a duration of about 0.2 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 16:09:29.2 UT, 78.1 seconds after the BAT trigger. No source was detected in 737 s of promptly downlinked data, which covered 93% of the BAT error circle. We are waiting for the full dataset to detect and localise the XRT counterpart. UVOT took a finding chart exposure of 150 seconds with the White filter starting 81 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 25% of the BAT 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 BAT 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 0.10. Burst Advocate for this burst is B.P. Gompertz (bpg6 AT 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: 14294 SUBJECT: GRB 130313A: MASTER-Net optical observations DATE: 13/03/13 16:47:08 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, D.Denisenko, A.Sankovich Sternberg Astronomical Institute, Moscow State University V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, Kourovka A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo 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 Blagoveschensk was pointed to the GRB130313A 27 sec after notice and 45 sec after GRB time at 2013-03-13 16:08:56.268 UT in two polarizations. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box (ra=15 45 39 dec=+00 21 34 r=0.05 d). The 5-sigma upper limit has been about 15.0 mag. MASTER II robotic telescope located in Tunka was pointed to the GRB130313A 85 sec after GRB time at 2013-03-13 16:09:36.11 UT in two polarizations. On our first (20s exposure) set we haven`t found optical transient within SWIFT error-box. The 5-sigma upper limit has been about 13.3 mag. Such a low limit is connected to large zenith distance of observed field (z>85 deg). The observations are continued. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14295 SUBJECT: GRB 130313A: Zadko observatory - Gingin optical observations DATE: 13/03/13 18:15:55 GMT FROM: Alain Klotz at IRAP-CNRS-OMP A. Klotz (IRAP-CNRS-OMP), D. Macpherson (UWA/ICRAR), D. Coward (UWA), B. Gendre (IRAP-CNRS-OMP), M. Boer, K. Siellez, H. Dereli , O. Bardho (UNS-CNRS-OCA), A. Williams (PO-UWA), R. Martin (PO-UWA) report: We imaged the field of GRB 130313A detected by SWIFT (trigger 550906) with the Zadko robotic telescope (D=100cm) located at the observatory - Gingin, Australia. The observations started 52.3s after the GRB trigger (34.2s after the notice). The elevation of the field increased from 19 degrees above horizon and weather conditions were good. The first image is trailed with a duration of 60.0s (see the description in Klotz et al., 2006, A&A 451, L39). We do not detect any optical transcient with a limiting magnitude of: t0+52.3s to t0+112.3s : R > 17.2 The second image is 30.0s exposure in tracking mode: t0+130s to t0+160s : R > 18.6 We co-added a series of exposures: t0+131s to t0+320.0s : R > 19.3 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14296 SUBJECT: GRB 130313A: Swift-BAT refined analysis DATE: 13/03/13 19:48:15 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), B.P. Gompertz (U Leicester), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-60 to T+180 sec from the recent telemetry downlink, we report further analysis of BAT GRB 130313A (trigger #550906) (Gompertz, et al., GCN Circ. 14293). The BAT ground-calculated position is RA, Dec = 236.438, -0.355 deg, which is RA(J2000) = 15h 45m 45.1s Dec(J2000) = -00d 21' 18.0" with an uncertainty of 2.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 82%. The mask-weighted light curve shows a single pulse starting at ~T+0.0, peaking at ~T+0.1 sec, and ending at ~T+0.2 sec. T90 (15-350 keV) is 0.26 +- 0.09 sec (estimated error including systematics). The time-averaged spectrum from T-0.02 to T+0.23 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.37 +- 0.36. The fluence in the 15-150 keV band is 3.1 +- 0.7 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T-0.36 sec in the 15-150 keV band is 0.5 +- 0.1 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/550906/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14297 SUBJECT: GRB 130313A: Swift-XRT detection of a possible X-ray afterglow DATE: 13/03/13 20:08:27 GMT FROM: Kim Page at U.of Leicester B.P. Gompertz & K.L. Page (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT started observing the field of the short GRB 130313A 78 s after the BAT trigger (Gompertz et al., GCN Circ. 14293). Using 662 s of XRT Photon Counting mode data, we find a possible weak source at a position of RA, Dec = 236.41005, -0.36874, which is equivalent to: RA (J2000): 15h 45m 38.41s Dec (J2000): -00d 22' 07.5" with an uncertainty of 5.3 arcsec (radius, 90% confidence). This is 1.9 arcmin from the BAT refined position (Barthelmy et al., GCN Circ. 14296), within the error circle. It is not possible to determine if the source is fading at this time. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14298 SUBJECT: GRB 130313A: Weihai optical upper limit DATE: 13/03/13 20:36:40 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI) and C. Cao, S.-M. Hu (SDU) report: We imaged the field of GRB 130313A (Gompertz et al., GCN 14293) with the 1m telescope located in Weihai, Shandong Province, China. Observations started at 17:41:25 UT on 2013-03-13 (i.e., 1.554 hr after the BAT trigger) and 5x600s R-band images were obtained. No optical source is detected within the XRT error circle (Gompertz & Page, GCN 14297) in the stacked image, down to a limit of R>20.5 mag calibrated with nearby USNO B1 stars. We thank Chang-Ming Zhang for carrying out these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14299 SUBJECT: GRB 130313A: simultaneous and follow-up optical observations at BOOTES-3 and BOOTES-4 DATE: 13/03/13 23:25:34 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia J. C. Tello (IAA-CSIC Granada), S. Guziy (Mykolaiv Nat. Univ.), O. Lara-Gil, R. Cunniffe, M. Jelinek (IAA-CSIC), J. Gorosabel (UPV/EHU-IAA/CSIC), P. Kubanek (IP AS CR), Y. Fan, X. Zhao, J. Bai, C. Wang, Y. Xin (Yunnan Nacional Astronomical Observatory), Ch. Cui (Beijing National Astronomical Observatory), W. Allen (Vintage Lane Obs.), Ph. Yock (Auckland Univ.) and A. J. Castro-Tirado (IAA-CSIC), on behalf of a larger collaboration, report: “Following the detection of GRB 130313A by Swift (Gompertz et al. GCNC 14293), both the 0.6m BOOTES-3/YA and BOOTES-4/MET robotic telescopes in Lijiang (China) and Blenheim (New Zealand) responded automatically to the trigger alert. Due to poor atmospheric/environmental conditions in both places, not deep limits were obtained: R > 15 (at BOOTES-3) with an unfiltered 60 second exposure beginning at 16h35m29s UT (27 minutes after the burst) and R > 18.5 (at BOOTES-4) beginning at 18h12m39s UT (2 hours after the burst). In addition to these late limits, the CASANDRA-3 wide-field system at BOOTES-3 took unfiltered images (36 seconds exposure each) beginning at 16h06m44s UT (87 seconds before the burst), 16h07m40s UT (31 seconds before the burst) and 16h08h36s UT (25 seconds after the burst). No credible transient is observed down to a limiting magnitude of R > 8.5.” //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14300 SUBJECT: GRB 130313A: Swift-XRT refined Analysis DATE: 13/03/14 04:27:04 GMT FROM: Phil Evans at U of Leicester J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), B. Sbarufatti (INAF-OAB/PSU), G. Stratta (ASDC), P. D'Avanzo (INAF-OAB), J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU) and B.P. Gompertz report on behalf of the Swift-XRT team: We have analysed 9.1 ks of XRT data for GRB 130313A (Gompertz et al. GCN Circ. 14293), from 85 s to 18.7 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 236.41004, -0.36897 which is equivalent to: RA (J2000): 15 45 38.41 Dec(J2000): -00 22 08.3 with an uncertainty of 4.8 arcsec (radius, 90% confidence). We cannot determine at the present time whether the source is fading. A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.6 (+3.4, -4.0). The best-fitting absorption column is consistent with the Galactic value of 5.9 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 7.0 x 10^-11 (7.8 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 0 (+1.7, -0) x 10^23 cm^-2 Galactic foreground: 5.9 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 1.6 (+3.4, -4.0) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00550906. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14301 SUBJECT: GRB 130313A: NOT optical upper limit DATE: 13/03/14 05:00:30 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), S. Schulze (PUC and MCSS), N. R. Tanvir (U. Leicester), H. Dahle, N. Groeneboom (U. Oslo), and J. P. U. Fynbo (DARK/NBI), report on behalf of a larger collaboration: We imaged the field of GRB 130313A (Gompertz et al., GCN 14293) using the 2.5m Nordic Optical Telescope (NOT) equipped with the ALFOSC instrument, located on La Palma, Canary Islands. Observations started at 02:16:32 UT on 2013-03-14 (i.e., 10.139 hr after the BAT trigger) and 12x300s SDSS_i-band images were obtained in good seeing of ~0.7". No object was found within the refined XRT error circle (Osborne et al., GCN 14300) in the stacked image, down to a limit of i>23.4 mag, calibrated with nearby SDSS stars. [GCN OPS NOTE(14mar13): Per author's request, NG was added to the author list.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14302 SUBJECT: GRB130313A: Optical observations from GTC DATE: 13/03/14 06:55:45 GMT FROM: Antonio de Ugarte Postigo at IAA-CSIC A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC), J. Gorosabel (IAA-CSIC), R. Sanchez-Ramirez (IAA-CSIC), J. P. U. Fynbo (DARK/NBI) and N. Tanvir (U. Leicester) report: We have observed the field of the short GRB 130313A (Gompertz et al., GCN 14293) using the 10.4m GTC. Observations started at 5:22 UT (13.23 hr after the burst) and were performed in the r-band in good conditions and a seeing of ~0.8". The combined 8x120s exposure covers the complete refined BAT error box (Barthelmy et al., GCN 14296). We detect a point-like source at the edge of the suggested X-ray afterglow (Osborne et al., GCN 14300) for which we estimate a preliminary magnitude of r=26.3+/-0.4, as compared with SDSS stars (we note that the photometry is complicated by a nearby bright star). This object is located at the following coordinates (J2000, +/-0.5"): S1: R.A.: 15:45:38.45 Dec.: -00:22:03.5 There are two other marginally detected sources consistent with the XRT error box, one unresolved at: S2: R.A.: 15:45:38.21 Dec.: -00:22:10.3 And one extended: S3: R.A.: 15:45:38.64 Dec.: -00:22:04.7 A finding chart with these sources can be found at: http://www.iaa.es/~deugarte/GRBs/130313A/130313A_GTC.jpg Further observations in search for variability will be needed to determine the relation of any of these sources with GRB 130313A. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14305 SUBJECT: GRB 130313A: Fading X-ray Afterglow DATE: 13/03/14 14:09:00 GMT FROM: Ben Gompertz at U.of Leicester B. P. Gompertz& K. L. Page (U. Leicester) report on behalf of the Swift-XRT team: Continuing Swift observations of GRB 130313A (Gompertz et al., GCN Circ. 14293) have shown the X-ray source identified by Gompertz& Page (GCN Circ. 14297) and Osborne et al. (GCN Circ. 14300) has faded. The first snapshot of data contains 10 counts in 326 seconds, giving a count rate of 0.012 ± 0.004 count s^-1, while later data provide an upper limit of 0.0025 count s^-1, corresponding to a single count in 22 ks of data. The souurce has faded and we therefore confirm that this is the X-ray afterglow of GRB 130313A. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14306 SUBJECT: GRB 130313A: Swift-BAT Spectral lag analysis DATE: 13/03/14 14:46:53 GMT FROM: Takanori Sakamoto at AGU J. Norris (BSU), T. Sakamoto (AGU), S. D. Barthelmy (GSFC), N. Gehrels (GSFC) We report the spectral lag analysis for GRB 130313A (GCN Circ. 14293 & 14296) based on the BAT data. Using 8-ms binned light curve, the spectral lag for the 15-25 keV to 50-100 keV bands is 9.2 (+11.5/-7.7) msec. These lag values place this burst in the short burst category. There is no evidence for extended emission. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14307 SUBJECT: GRB 130313A: TNG optical observations DATE: 13/03/14 15:45:14 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, S. Covino, A. Melandri (INAF/OAB), C. P. Padilla Torres, G. Andreuzzi (INAF/TNG) report on behalf of the CIBO collaboration: We observed the field of GRB 130313A (Gompertz et al., GCN 14293) with the TNG telescope located in the Canary Islands. A total 1800 s exposure in the SDSS r filter was acquired, with mean time 2013 Mar 14.2314 UT (13.4 hours after the GRB). Sky conditions were good and the seeing was 0.9". No clear optical afterglow is detected inside the refined XRT error circle (Osborne et al. GCN 14300; Gompertz et al., GCN 14305) down to a limiting magnitude r~25 mag (3sigma c.l.; calibrated against nearby SDSS stars). In particular, we do not detect the 3 optical sources reported by de Ugarte Postigo et al. (GCN 14302). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14308 SUBJECT: GRB 130313A: RATIR Optical and NIR Observations DATE: 13/03/14 15:56:30 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 (UCSC), Eleonora Troja (GSFC), 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 the short-duration GRB 130313A (Gompertz, et al., GCN 14293) 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 2013 March 14.30 to 2013 March 14.52 UTC (14.96 to 20.25 hours after the BAT trigger), obtaining a total of 3.5 hours exposures in the r' and i' bands and 1.5 hours of exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle (Osborne et al., GCN 14293; Gompertz et al., GCN 14305), in comparison with SDSS DR8 and 2MASS, we derive the following upper limits (3-sigma) in the AB magnitude system: r' > 23.6 i' > 23.3 Z > 22.3 Y > 22.0 J > 21.8 H > 21.3 These magnitudes 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: 14314 SUBJECT: GRB 130313A: Swift/UVOT Upper Limits DATE: 13/03/15 21:41:57 GMT FROM: Tyler Pritchard at PSU T. A. Pritchard (PSU) and B. P. Gompertz (U Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 130313A 81 s after the BAT trigger (Gompertz et al., GCN Circ. 14293). No optical afterglow consistent with the XRT position (Osborne et al. GCN Circ. 14300) 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 81 231 147 >20.6 u_FC 293 543 246 >20.3 white 81 17899 2332 >22.4 v 625 22348 1681 >20.4 b 550 16987 1327 >21.4 u 293 6955 697 >20.3 w1 674 6750 471 >20.9 m2 649 6545 413 >21.0 w2 600 18671 2110 >21.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.09 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14318 SUBJECT: GRB 130313A: 5.8 GHz VLA upper limit DATE: 13/03/16 05:55:06 GMT FROM: Wen-fai Fong at CFA W. Fong, B. A. Zauderer and E. Berger (Harvard) report: "We observed the position of the short-duration GRB 130313A (Gompertz et al., GCN 14293) with the Karl G. Jansky Very Large Array (VLA) beginning on 2013 March 14.44 UT (18.5 hr post-burst) at a mean frequency of 5.8 GHz. In 1 hour of observations, we do not detect any source within the BAT-refined position (Barthelmy et al., GCN 14296), within the latest XRT position (Osborne et al., GCN 14300), or in coincidence with any of the reported optical sources (de Ugarte Postigo et al., GCN 14302). We therefore place a 3-sigma limit of ~60 microJy on the radio counterpart of GRB 130313A at 18.5 hr after the burst." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14319 SUBJECT: GRB130313A: GTC early optical limits DATE: 13/03/16 08:10:39 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia J. Gorosabel (UPV/EHU-IAA/CSIC), J.C. Tello, R. Sánchez-Ramírez, M. Jelinek, A. J. Castro-Tirado (IAA-CSIC Granada), report on behalf of a larger collaboration: "We have observed the field of the short duration GRB 130313A (Gompertz et al., GCN 14293) using the 10.4m GTC in Sloan r,i and z filters with a seeing of ~1.3", however at an airmass of ~1.4 and with cirruses across the field. The combined exposure of 12x70 s images with a Sloan i filter taken starting 02:54:47UT and ending 03:14:58UT (10.7 - 11.1 hours after the burst) shows no afterglow candidate within the refined XRT uncertainty circle (Osborne et al., GCN 14300) down to a magnitude of i > 23.5 when compared to the SDSS Photometric Catalog, Release 6." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14321 SUBJECT: GRB 130313A: optical upper limit in Mondy observatory DATE: 13/03/16 19:54:28 GMT FROM: Alexei Pozanenko at IKI, Moscow A.Volnova (SAI MSU/IKI), E. Klunko (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 130313A (Gompertz et al., GCN 14293) with AZT-33IK telescope of Sayan observatory (Mondy) on March 13 between (UT) 17:45:47 - 22:55:49. We took several images in R-filter of 90 s exposure which cover partially the refined BAT error box (Barthelmy et al., GCN 14296). Within XRT position (Gompertz et al., GCN 14297; Osborne et al., GCN 14300) we do not detect any source. Preliminary photometry of combined images is following UT start, t-t0 filter Exp. OT UL (3 sigma) (mid, days) (s) 17:54:56 0.06737 R 20x90 n/d 20.3 17:54:56 0.17047 R 147x90 n/d 23.3 The photometry is based on two SDSS DR8 stars SDSS J154537.18-001931.3 RA = 15 45 37.18 Dec = -00 19 31.3 (J2000), R = 18.95 SDSS J154535.15-001918.8 RA = 15 45 35.15 Dec = -00 19 18.8 (J2000), R = 16.76 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14322 SUBJECT: GRB 130313A: optical upper limit in CrAO DATE: 13/03/16 19:54:45 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 130313A (Gompertz et al., GCN 14293) with ZTSh telescope of CrAO observatory (Mondy) on March 14 between (UT) 00:23:52 - 02:11:00. We took several images in R-filter of 60 s exposure which cover the refined BAT error box (Barthelmy et al., GCN 14296). Within XRT position (Gompertz et al., GCN 14297; Osborne et al., GCN 14300) we do not detect any source. Preliminary photometry of a combined image is following UT start, t-t0 filter Exp. OT UL (3 sigma) (mid, days) (s) 00:23:52 0.3818 R 24x60 n/d 22.7 The photometry is based on USNO-B1.0 star 0896-0256107 15:45:37.83 -00:22:18.2 R=16.04