//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27517 SUBJECT: Swift GRB200410.10: Global MASTER-Net observations report DATE: 20/04/10 02:40:18 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (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 GRB200410.10 (trigger No 965638,19h 58m 32.88s , +51d 45m 46.8s, R=0.05) errorbox 16 sec after notice time and 55 sec after trigger time at 2020-04-10 02:26:05 UT, with upper limit up to 16.1 mag. Observations started at twilight. The observations began at zenith distance = 23 deg. The sun altitude is -8.2 deg. The galactic latitude b = 11 deg., longitude l = 86 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1333659 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 60 | MASTER-Tavrida | C | 10 | 15.5 | 80 | MASTER-Tavrida | C | 50 | 16.1 | Coadd 96 | MASTER-Tavrida | C | 20 | 15.7 | 136 | MASTER-Tavrida | C | 20 | 15.5 | 181 | MASTER-Tavrida | C | 30 | 15.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27518 SUBJECT: GRB 200410A: Swift detection of a burst with a possible optical counterpart DATE: 20/04/10 02:49:58 GMT FROM: Scott Barthelmy at NASA/GSFC K. K. Simpson (PSU), S. D. Barthelmy (GSFC), J.D. Gropp (PSU), J. A. Kennea (PSU), N. J. Klingler (PSU), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), M. H. Siegel (PSU) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 02:25:10 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 200410A (trigger=965638). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 299.637, +51.763, which is RA(J2000) = 19h 58m 33s Dec(J2000) = +51d 45' 48" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows multiple peaks with a total duration of about 45 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 02:26:51.7 UT, 101.3 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 299.6456, 51.7813 which is equivalent to: RA(J2000) = 19h 58m 34.94s Dec(J2000) = +51d 46' 52.5" with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 68 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 in excess of the Galactic value (2.15 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 2.3 (+2.17/-1.95) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 104 seconds after the BAT trigger. There is a possible candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 19:58:35.32 = 299.64717 DEC(J2000) = +51:46:53.0 = +51.78138 with a 90%-confidence error radius of about 0.6 arc sec. This position is 3.5 arc sec. from the center of the XRT error circle. The estimated magnitude is 18.71 with a 1-sigma error of about 0.15. No correction has been made for the expected extinction corresponding to E(B-V) of 0.15. Burst Advocate for this burst is K. K. Simpson (kira.simpson1984 AT gmail.com). 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/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27520 SUBJECT: GRB 200410A: Ondrejov D50 afterglow confirmation DATE: 20/04/10 04:01:45 GMT FROM: Martin Jelinek at Astro.Inst-AVCR,Ondrejov M. Jelinek, J. Strobl, R. Hudec, C. Polasek (ASU CAS Ondrejov) report: We observed the position of the GRB 200410A (Simpson et al., GCN 27518) with the D50 telescope of the Astronomical Institute Ondrejov, near Prague, Czech Republic, obtaining a series of 10s unfiltered images starting at 02:26:05.4UT, i.e. 55s post trigger. The optical afterglow reported from UVOT (Simpson et al., GCN 27518) is detected in the early single 20 s images. We note the presence of two nearby stars which may confuse the observer and/or complicate photometry. For this reason, we do not provide brightness at this stage. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27522 SUBJECT: GRB 200410A: Enhanced Swift-XRT position DATE: 20/04/10 07:18:55 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 1479 s of XRT Photon Counting mode data and 1 UVOT images for GRB 200410A, 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 = 299.64593, +51.78078 which is equivalent to: RA (J2000): 19h 58m 35.02s Dec (J2000): +51d 46' 50.8" with an uncertainty of 1.9 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: 27523 SUBJECT: GRB 200410A: Swift-XRT refined Analysis DATE: 20/04/10 10:52:09 GMT FROM: Phil Evans at U of Leicester J. D. Gropp (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto) and K.K. Simpson report on behalf of the Swift-XRT team: We have analysed 7.0 ks of XRT data for GRB 200410A (Simpson et al. GCN Circ. 27518), from 86 s to 24.4 ks after the BAT trigger. The data comprise 15 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 Goad et al. (GCN Circ. 27522). The light curve can be modelled with an initial power-law decay with an index of alpha=4.2 (+2.6, -0.8), followed by a break at T+148 s to an alpha of 0.58 (+/-0.04). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.99 (+0.18, -0.17). The best-fitting absorption column is 2.7 (+0.7, -0.5) x 10^21 cm^-2, consistent with the Galactic value of 2.2 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 3.7 x 10^-11 (5.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.7 (+0.7, -0.5) x 10^21 cm^-2 Galactic foreground: 2.2 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.99 (+0.18, -0.17) If the light curve continues to decay with a power-law decay index of 0.58, the count rate at T+24 hours will be 0.037 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.4 x 10^-12 (1.9 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/00965638. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27532 SUBJECT: GRB 200410A: Swift/UVOT Detection DATE: 20/04/10 21:38:49 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and K. K. Simpson (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 200410A 104 s after the BAT trigger (Simpson et al., GCN Circ. 27518). A source consistent with the XRT position (Goad et al. GCN Circ. 27522) is detected in the initial UVOT exposures. The uvot position has been determined from the first white image to be RA = 19:58:35.3 Dec = +51:46:53.0 or 299.64717 =51.78138 Deg (J2000) with an error estimate of 0.5". There are two nearby stars visible at 4 and 6 arcsec. 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 104 254 147 19.51 +/- 0.14 v 5051 6869 396 21.23 +/- 0.90 b 572 1519 98 19.61 +/- 0.32 u 317 567 246 20.39 +/- 0.37 w1 696 1294 57 >19.8 m2 671 1220 57 >20.0 w2 622 1270 57 >19.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.15 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27578 SUBJECT: GRB 200410A: Swift-BAT refined analysis DATE: 20/04/15 03:19:33 GMT FROM: Amy Lien at GSFC S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), K. K. Simpson (PSU), M. Stamatikos (OSU), 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 200410A (trigger #965638) (Simpson et al., GCN Circ. 27518). The BAT ground-calculated position is RA, Dec = 299.644, 51.745 deg which is RA(J2000) = 19h 58m 34.6s Dec(J2000) = +51d 44' 40.9" with an uncertainty of 2.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 53%. The mask-weighted light curve shows several weak pulses. The two main pulses occur at ~T-20 s and ~T+2 s, respectively, followed by some weak emission that lasts till ~T+50 s. T90 (15-350 keV) is 108.8 +- 40.7 sec (estimated error including systematics). The time-averaged spectrum from T-90.88 to T+50.62 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.41 +- 0.31. The fluence in the 15-150 keV band is 1.2 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+1.43 sec in the 15-150 keV band is 1.8 +- 0.3 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/965638/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27584 SUBJECT: GRB 200410A: CALET Gamma-Ray Burst Monitor detection DATE: 20/04/15 12:20:30 GMT FROM: Valentin Pal'shin at AGU N. Cannady (GSFC/UMBC), A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The Swift GRB 200410A (Simpson et al., GCN Circ. 27518, Laha et al., GCN Circ. 27578; https://gcn.gsfc.nasa.gov/other/200410A.gcn3) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 02:25:15.105 UTC on 10 April 2020. The burst signal was seen by the SGM detector. No real-time CGBM GCN notice was distributed about this trigger because the real-time communication from the ISS was off (loss of signal). The burst light curve shows a weak pulse which starts at T-3.9 sec, peaks at T-1.0 sec and ends at T+2.4 sec. The T90 and T50 durations measured by the SGM data are 5.5 +- 2.2 sec and 2 +- 2 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1270520355/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27603 SUBJECT: GRB 200410A: Optical upper limit DATE: 20/04/18 07:14:21 GMT FROM: Amit Kumar at ARIES, India A. Kumar (ARIES), A. Ghosh (ARIES), Dimple (ARIES), A. Aryan (ARIES), R. Gupta (ARIES), S. B. Pandey (ARIES), and K. Misra (ARIES) report: We observed the field of Swift GRB 200410A (Simpson et al., GCN Circ. 27518, Gropp et al., GCN 27523, Kuin et al., GCN 27532, Pizzuto et al., GCN 27552, Laha et al., GCN Circ. 27578, Valentin et al., GCN 27584) with the 1.3m Devsthal Fast Optical Telescope (DFOT) at Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital (India), from 2020-04-10 UT 21:34:29 to 2020-04-10 UT 23:31:07 (corresponding to 19.15 to 21.09 hours from the GRB trigger time). We observed 12 frames each of 300 seconds in Bessel R filter and a series of 11x300 seconds exposures in Bessel I filter. As mentioned by Jelinek et al., 27520, at the position of the optical afterglow of GRB 200410A there are two nearby stars, so to do the photometry we observed 300 seconds frame in Bessel R and I filter on 2020-04-15 UT 21:26:22 (5.79 days since burst) to do the template subtraction. Template subtraction was done using the IRAF ( http://iraf.noao.edu/). After the template subtraction, we do not find any new optical source within the Swift XRT enhanced error circle in any individual as well as the stacked frame. The 3-sigma upper limits are as follows: T_start-T0 (days) Start Date (UTC) End Date (UTC) Filter 3-sigma upper limit (mag) --------------------------------------------------------------------------------------------------------------- 19.15 2020-04-10 21:34:29 2020-04-10 22:30:06 R >22.2 20.18 2020-04-10 22:35:46 2020-04-10 23:31:07 I >22.4 Photometry is done based on the USNO-B1.0 catalog. The quoted magnitudes are not corrected for Galactic extinction. [GCN OPS NOTE(18apr20): The author-constructed header was removed. The header is supplied by the GCN processing system.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27621 SUBJECT: GRB 200410A: Liverpool Telescope First Hour Observations DATE: 20/04/22 11:40:04 GMT FROM: Iain Steele at Liverpool/JMU I.A. Steele, M. Shrestha, S. Kobayashi (Liverpool JMU), C. Mundell (Univ. Bath), A. Gomboc (Univ. Nova Gorica) report on behalf of a wider collaboration: We observed the field of Swift GRB 200410A (GCN 27518) with the 2.0m Liverpool Telescope, La Palma on 2020 Apr 10 starting at 02:28:38 UT using the IOO optical camera for a period of ~1 hour in the r’ and I’ bands. The target was well resolved from the two nearby stars. Data was calibrated with respect to APASS secondary standard stars in the images. We confirm the optical counterpart reported by Swift UVOT and Ondrejov (GCN 27520). At T=155 seconds after the BAT trigger time, we measure r’ = 18.2. Both the r’ and i’ band light curves subsequently show a power law decay in flux vs time with alpha = 0.7 over the first hour. ________________________________ Important Notice: the information in this email and any attachments is for the sole use of the intended recipient(s). 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