July 2024 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 34849] GRB 240730B: Fermi GBM Final Real-time Localization
by GCN Circulars 30 Jul '24

30 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36984 SUBJECT: GRB 240730B: Fermi GBM Final Real-time Localization DATE: 24/07/30 19:48:53 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 19:38:18 UT on 30 Jul 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240730B (trigger 744061103.370314 / 240730818). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 202.2, Dec = 23.2 (J2000 degrees, equivalent to J2000 13h 28m, 23d 11'), with a statistical uncertainty of 1.0 degrees. The angle from the Fermi LAT boresight is 130.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240730818/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240730818/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240730818/… View this GCN Circular online at https://gcn.nasa.gov/circulars/36984. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 34848] Swift GRB 240730A: Global MASTER-Net observations report
by GCN Circulars 30 Jul '24

30 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36983 SUBJECT: Swift GRB 240730A: Global MASTER-Net observations report DATE: 24/07/30 18:56:28 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich (Blagoveschensk Educational State University) MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 240730A ( S. B. Cenko et al., GCN 36976) errorbox 37782 sec after notice time and 37859 sec after trigger time at 2024-07-30 18:23:05 UT, with upper limit up to 16.8 mag. Observations started at twilight. The observations began at zenith distance = 71 deg. The sun altitude is -11.9 deg. The galactic latitude b = -1 deg., longitude l = 136 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2545484 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 32544 | MASTER- | C | 30 | 18.9 | 32585 | MASTER- | C | 30 | 18.8 | 32627 | MASTER- | C | 30 | 18.8 | 32671 | MASTER- | C | 30 | 18.8 | 32719 | MASTER- | C | 30 | 18.6 | 32762 | MASTER- | C | 30 | 19.0 | 33359 | MASTER- | C | 30 | 18.8 | 33403 | MASTER- | C | 30 | 18.9 | 34542 | MASTER- | C | 180 | 19.4 | 34735 | MASTER- | C | 180 | 19.5 | 34928 | MASTER- | C | 180 | 19.4 | 35120 | MASTER- | C | 180 | 19.3 | 35313 | MASTER- | C | 180 | 19.4 | 35509 | MASTER- | C | 180 | 19.1 | 35703 | MASTER- | C | 180 | 19.3 | 35821 | MASTER- | C | 30 | 19.1 | 35868 | MASTER- | C | 30 | 19.1 | 35915 | MASTER- | C | 30 | 19.1 | 35957 | MASTER- | C | 30 | 19.1 | 36000 | MASTER- | C | 30 | 19.1 | 36042 | MASTER- | C | 30 | 19.1 | 36085 | MASTER- | C | 30 | 18.9 | 36121 | MASTER- | C | 30 | 19.1 | 36163 | MASTER- | C | 30 | 19.1 | 36206 | MASTER- | C | 30 | 19.1 | 36248 | MASTER- | C | 30 | 19.1 | 36291 | MASTER- | C | 30 | 18.8 | 36970 | MASTER- | C | 180 | 18.9 | 37949 | MASTER-Tavrida | C | 180 | 16.8 | 38248 | MASTER- | C | 180 | 19.3 | 39462 | MASTER- | C | 180 | 19.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/36983. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 34847] Swift GRB 240730A: Global MASTER-Net observations report
by GCN Circulars 30 Jul '24

30 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36983 SUBJECT: Swift GRB 240730A: Global MASTER-Net observations report DATE: 24/07/30 18:56:28 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich (Blagoveschensk Educational State University) MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 240730A ( S. B. Cenko et al., GCN 36976) errorbox 37782 sec after notice time and 37859 sec after trigger time at 2024-07-30 18:23:05 UT, with upper limit up to 16.8 mag. Observations started at twilight. The observations began at zenith distance = 71 deg. The sun altitude is -11.9 deg. The galactic latitude b = -1 deg., longitude l = 136 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2545484 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 32544 | MASTER- | C | 30 | 18.9 | 32585 | MASTER- | C | 30 | 18.8 | 32627 | MASTER- | C | 30 | 18.8 | 32671 | MASTER- | C | 30 | 18.8 | 32719 | MASTER- | C | 30 | 18.6 | 32762 | MASTER- | C | 30 | 19.0 | 33359 | MASTER- | C | 30 | 18.8 | 33403 | MASTER- | C | 30 | 18.9 | 34542 | MASTER- | C | 180 | 19.4 | 34735 | MASTER- | C | 180 | 19.5 | 34928 | MASTER- | C | 180 | 19.4 | 35120 | MASTER- | C | 180 | 19.3 | 35313 | MASTER- | C | 180 | 19.4 | 35509 | MASTER- | C | 180 | 19.1 | 35703 | MASTER- | C | 180 | 19.3 | 35821 | MASTER- | C | 30 | 19.1 | 35868 | MASTER- | C | 30 | 19.1 | 35915 | MASTER- | C | 30 | 19.1 | 35957 | MASTER- | C | 30 | 19.1 | 36000 | MASTER- | C | 30 | 19.1 | 36042 | MASTER- | C | 30 | 19.1 | 36085 | MASTER- | C | 30 | 18.9 | 36121 | MASTER- | C | 30 | 19.1 | 36163 | MASTER- | C | 30 | 19.1 | 36206 | MASTER- | C | 30 | 19.1 | 36248 | MASTER- | C | 30 | 19.1 | 36291 | MASTER- | C | 30 | 18.8 | 36970 | MASTER- | C | 180 | 18.9 | 37949 | MASTER-Tavrida | C | 180 | 16.8 | 38248 | MASTER- | C | 180 | 19.3 | 39462 | MASTER- | C | 180 | 19.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/36983. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 34846] GRB 240730A: Swift-XRT refined Analysis
by GCN Circulars 30 Jul '24

30 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36982 SUBJECT: GRB 240730A: Swift-XRT refined Analysis DATE: 24/07/30 16:44:42 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> S. Dichiara (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), M. Ferro (INAF-OAB), R. Brivio (INAF-OAB), A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 7.2 ks of XRT data for GRB 240730A, from 113 s to 23.5 ks after the BAT trigger. The data comprise 14 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 light curve can be modelled with a power-law decay with a decay index of alpha=2.04 (+/-0.24). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.6 (+/-0.4). The best-fitting absorption column is 1.4 (+0.6, -0.5) x 10^22 cm^-2, in excess of the Galactic value of 7.8 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 6.8 x 10^-11 (1.0 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.4 (+0.6, -0.5) x 10^22 cm^-2 Galactic foreground: 7.8 x 10^21 cm^-2 Excess significance: 2.1 sigma Photon index: 1.6 (+/-0.4) If the light curve continues to decay with a power-law decay index of 2.04, the count rate at T+24 hours will be 5.4 x 10^-6 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.6 x 10^-16 (5.7 x 10^-16) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01245636. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/36982. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 34845] GRB 240715A: Swift-XRT afterglow detection
by GCN Circulars 30 Jul '24

30 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36981 SUBJECT: GRB 240715A: Swift-XRT afterglow detection DATE: 24/07/30 16:04:49 GMT FROM: Chiara Salvaggio at INAF OABrera <chiara.salvaggio(a)inaf.it> C. Salvaggio (INAF-OAB), K. L. Page (U. Leicester) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed further follow-up observations of the IPN-detected burst GRB 240715A (Kozyrev et al., GCN Circ. 36872). The data were collected between T0+36.0 ks ks and T0+1270 ks, for a total exposure time of 17.7 ks. The uncatalogued X-ray source reported by D'Elia et al. ("Source 3"; GCN Circ. 36890), with a count-rate of 4.0 [+1.4, -1.2]e-3 ct s^-1, is no more detected: we derive an upper limit of 1.4e-3 ct s^-1. Source 3 shows significant signs of fading, and is therefore likely the GRB afterglow. The X-ray afterglow light curve can be modelled with a power-law with no breaks and decay index alpha > 0.63. The results of the XRT-team automatic analysis are available at https://www.swift.ac.uk/xrt_products/00021699. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/36981. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 34844] GRB 240730A: KAIT Optical Upper Limit
by GCN Circulars 30 Jul '24

30 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36980 SUBJECT: GRB 240730A: KAIT Optical Upper Limit DATE: 24/07/30 15:59:11 GMT FROM: Weikang Zheng at UC Berkeley <weikang(a)berkeley.edu> WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 240730A (Cenko et al., GCN 36976) starting at 10:24UT, ~2.53 hours after the burst. A total of 50x60s images were obtained in the clear (roughly R) filters. We do not detect any optical afterglow candidate within the enhanced XRT position error circle (Evans et al., GCN 36977), neither in single image, nor in the co-add images. The typical limiting magnitude of our single clear image is about 19.5 mag calibrated to the PS1 catalog. View this GCN Circular online at https://gcn.nasa.gov/circulars/36980. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 34843] GRB 240727C: GRBAlpha detection
by GCN Circulars 30 Jul '24

30 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36979 SUBJECT: GRB 240727C: GRBAlpha detection DATE: 24/07/30 14:35:02 GMT FROM: Marianna Dafčíková at Masaryk University <500025(a)mail.muni.cz> M. Dafcikova, J. Ripa, M. Kolar (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Duriskova, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration. The long-duration GRB 240727C (AstroSat/CZTI detection: GCN 36957; INTEGRAL/SPI-ACS detection: trigger no. 10817; Konus/Wind detection trigger at 2024-07-27 17:30:03.986 UTC) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..40P/abstract) The detection was confirmed at the peak time 2024-07-27 17:30:07.7 UTC. The T90 duration measured by GRBAlpha is 6.5 s and the overall significance during T90 reaches 13.3 sigma. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB240727C_GCN.pdf All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/ GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume. View this GCN Circular online at https://gcn.nasa.gov/circulars/36979. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 34842] GRB 240730A: Swift/UVOT Upper Limits
by GCN Circulars 30 Jul '24

30 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36978 SUBJECT: GRB 240730A: Swift/UVOT Upper Limits DATE: 24/07/30 12:36:41 GMT FROM: Paul Kuin at MSSL <npkuin(a)gmail.com> Paul Kuin (MSSL/UCL), R. Caputo and S. B. Cenko (GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 240730A 133 s after the BAT trigger (Cenko et al., GCN Circ. 36976). No optical afterglow consistent with the XRT position in Evans et al., GCN Circ. 36977, 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 133 283 147 >19.1 u_FC 291 541 246 >19.2 white 133 1026 295 >19.1 u 291 541 246 >19.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 1.146 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/36978. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 34841] GRB 240730A: Enhanced Swift-XRT position
by GCN Circulars 30 Jul '24

30 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36977 SUBJECT: GRB 240730A: Enhanced Swift-XRT position DATE: 24/07/30 10:46:37 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 915 s of XRT Photon Counting mode data and 2 UVOT images for GRB 240730A, 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 = 37.83822, +59.02875 which is equivalent to: RA (J2000): 02h 31m 21.17s Dec (J2000): +59d 01' 43.5" with an uncertainty of 2.6 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/36977. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 34840] GRB 240730A: Swift detection of a burst
by GCN Circulars 30 Jul '24

30 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36976 SUBJECT: GRB 240730A: Swift detection of a burst DATE: 24/07/30 08:11:21 GMT FROM: David Palmer at LANL <palmer(a)lanl.gov> S. B. Cenko (GSFC), P. A. Evans (U Leicester), R. A. J. Eyles-Ferris (U Leicester), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift Observatory Team: At 07:52:06 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 240730A (trigger=1245636). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 37.829, +59.074 which is RA(J2000) = 02h 31m 19s Dec(J2000) = +59d 04' 27" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 80 sec. The peak count rate was ~300 counts/sec (15-350 keV), at ~30 sec after the trigger. The XRT began observing the field at 07:54:14.8 UT, 128.7 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 37.83844, 59.02878 which is equivalent to: RA(J2000) = 02h 31m 21.22s Dec(J2000) = +59d 01' 43.6" with an uncertainty of 1.9 arcseconds (radius, 90% containment). This location is 163 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 https://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 7.80 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 133 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 coverage of the XRT error circle by the 8'x8' region for the list of sources generated on-board is uncertain because the large number of sources filled the available telemetry. The list of sources is typically complete to about 18 mag. No correction has been made for the large, but uncertain, extinction expected. Although this appears to be a long GRB, its long duration and its position near the Galactic plane (lat=-1.35) raise the possibility that this is a Galactic transient instead. If that is the case then we give it the name Swift J0231.3+5902 . Burst Advocate for this burst is S. B. Cenko (brad.cenko AT 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/) View this GCN Circular online at https://gcn.nasa.gov/circulars/36976. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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