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

[vsnet-grb-info 33682] GRB 240225B: 3.6m DOT observation
by GCN Circulars 29 Feb '24

29 Feb '24

TITLE: GCN CIRCULAR NUMBER: 35830 SUBJECT: GRB 240225B: 3.6m DOT observation DATE: 24/02/29 06:15:59 GMT FROM: Amit Kumar Ror at ARIES <mitturor77894(a)gmail.com> Amit K. Ror, Shashi B. Pandey, Rahul Gupta, and Amar Aryan, Shivangi Pandey (ARIES) report: We observed the field of GRB 240225B detected by MAXI (Nakajima et al. 2024, GCN 35796), Swift (Evans 2024, GCN 35797), and AstroSat (Joshi et al. 2024, GCN 35798) using the 3.6m Devasthal Optical Telescope of ARIES Nainital. The observations were started on 2024-02-28 at 01:04:01.085 UT, i.e., 2.2 days after the MAXI trigger. We have taken multiple frames with a 60-second exposure time in the r, i, and z filters. We detected the OT at the position of the GOTO afterglow candidate reported by Gompertz et al. (2024, GCN 35805) in each observed image in the i and z bands and the stacked image of the r band, indicating a redder nature. The preliminary magnitude measurements are as follows: Date Start_UT T_start-T0 (days) Filter Exp time (s) Limiting magnitude ========================================================= 2024-02-28 01:04:01.085 2.2 i 60s 19.96 +/- 0.04 Our i-band observation, combined with the observation of Wise et al. (2024, GCN 35820), yielded a decay index of ~ 0.8 in the i-band. The magnitude quoted is not corrected for the host and Galactic extinction in the direction of the burst. Photometric calibration is performed using the standard stars from the Pan-STARRS catalog. Our detection is consistent with Gompertz et al. 2024, GCN 35805; Liu et al. 2024, GCN 35812; Malesani et al. 2024, GCN 35819; Wise et al. 2024, GCN 35820; Gompertz et al. 2024, GCN 35824; Pankov et al. 2024, GCN 35826; Moskvitin et al. 2024, GCN 35828; and Geoffrey et al. 2024, GCN 35829. This circular may be cited. 3.6m Devasthal Optical Telescope (DOT) is a recently commissioned facility in the Northern Himalayan region of India (long:79 41 04E, lat:29 21 40N, alt:2540m) owned and operated by the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital ( https://www.aries.res.in). Authors of this GCN circular thankfully acknowledge consistent support from the staff members to run and maintain the 3.6m DOT. View this GCN Circular online at https://gcn.nasa.gov/circulars/35830. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33681] GRB 240225B: WINTER near-IR observations and upper limits
by GCN Circulars 29 Feb '24

29 Feb '24

TITLE: GCN CIRCULAR NUMBER: 35829 SUBJECT: GRB 240225B: WINTER near-IR observations and upper limits DATE: 24/02/29 01:10:22 GMT FROM: Geoffrey Mo at MIT <gmo(a)mit.edu> Geoffrey Mo (MIT), Viraj Karambelkar (Caltech), Danielle Frostig (MIT), Robert Stein (Caltech), Nathan Lourie (MIT), Tomas Ahumada (Caltech), Robert Simcoe (MIT), Mansi Kasliwal (Caltech) report: We observed the field of GRB 240225B (Nakajima et al., GCN 35796; Evans, GCN 35797; Joshi et al., GCN 35798; D'Ai et al., GCN 35810; Kawakubo et al., GCN 35811) using the Palomar 1-m telescope equipped with the 1-square degree infrared WINTER camera (Lourie et al., 2020) in the Y and J bands. Observations began at 2024-02-28T05:55:09 UTC (~2.4 days after the GRB) and consisted of 8 x 120 s exposures in each filter. The images were processed using the WINTER data reduction pipeline (https://github.com/winter-telescope/mirar), with J-band image subtraction performed against reference images from the UKIRT Hemisphere Survey (Dye et al., 2017). We do not detect the GOTO-discovered counterpart (Gompertz et al., GCN 35805; Liu et al., GCN 35812; Malesani et al., GCN 35819; Wise et al., GCN 35820; Gompertz & Malesani, GCN 35824; Pankov et al., GCN 35826; Moskvitin et al., GCN 35828), setting the following upper limits (AB): Y = 18.3 mag and J = 18.8 mag. View this GCN Circular online at https://gcn.nasa.gov/circulars/35829. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33680] GRB 240225B: SAO RAS optical observations
by GCN Circulars 28 Feb '24

28 Feb '24

TITLE: GCN CIRCULAR NUMBER: 35828 SUBJECT: GRB 240225B: SAO RAS optical observations DATE: 24/02/28 22:16:52 GMT FROM: Moskvitin Alexander at SAO RAS <mosk(a)sao.ru> A. S. Moskvitin, O. I. Spiridonova (SAO RAS) report on behalf of the GRB follow-up team. We observed the field of GRB 240225B (Nakajima et al., GCN 35796; Evans, GCN 35797; Joshi et al., GCN 35798; D'Ai et al., GCN 35810; Kawakubo et al., GCN 35811) with the SAO RAS 1m telescope Zeiss-1000 equipped with CCD-photometer. We obtained 8 x 300 sec frames in the Rc band on Feb. 28, 18:20:36--19:11:22 UT (t_mid - T0 = 2.9307 days). The OT (Gompertz et al., GCN 35805; Liu et al., GCN 35812; Malesani et al., GCN 35819; Wise et al., GCN 35820; Gompertz & Malesani, GCN 35824; Pankov et al., GCN 35826) is clearly detected in our stacked frame with the brightness of R = 20.51 +/- 0.02. The photometry is based on nearby SDSS stars (magnitudes converted with Lupton 2005 equations). View this GCN Circular online at https://gcn.nasa.gov/circulars/35828. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33679] GRB 240226A: GRBAlpha detection
by GCN Circulars 28 Feb '24

28 Feb '24

TITLE: GCN CIRCULAR NUMBER: 35827 SUBJECT: GRB 240226A: GRBAlpha detection DATE: 24/02/28 13:31:18 GMT FROM: Martin Kolář at Masaryk University <mkolar(a)physics.muni.cz> M. Kolar, M. Dafcikova, J. Ripa (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, 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 240226A (Fermi/GBM detection: GCN 35804) 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 sub-threshold detection was confirmed at the peak time 2024-02-26 19:33:09.5 UTC. The T90 duration measured by GRBAlpha is 9.5 s and the overall significance during T90 reaches 4.7 sigma. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB240226A_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/35827. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33678] GRB 240225B: Mondy afterglow observations
by GCN Circulars 28 Feb '24

28 Feb '24

TITLE: GCN CIRCULAR NUMBER: 35826 SUBJECT: GRB 240225B: Mondy afterglow observations DATE: 24/02/28 07:44:44 GMT FROM: Alexei Pozanenko at IKI, Moscow <apozanen(a)iki.rssi.ru> N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI, HSE) report on behalf of IKI-GRB-FuN: We observed the field of GRB 240225B (Nakajima et al., GCN 35796; Evans, GCN 35797, Joshi et al., GCN 35798; D'Ai et al., GCN 35810; Kawakubo et al., GCN 35811) with AZT-33IK telescope of Sayan observatory (Mondy) equipped with CMOS-photometer ANDOR NEO. We took 60x120 sec frames in the R-filter starting on 2024-02-26 (UT) 12:30:03. The optical afterglow (Gompertz et al., GCN 35805; Liu et al., GCN 35812; Malesani et al., GCN 35819; Wise et al., GCN 35820; Gompertz & Malesani, GCN 35824) is well detected in the stacked frame with a total exposure of 59x120 sec. Photometry of the optical afterglow is following: Date UT-start t-T0 Exp Filter OT Err UL FWHM (UT) (mid.) (nxT) (3sigma) (arcsec) 2024-02-27 13:01:23 1.71919 59x120 R 19.16 0.09 22.8 2.1 The magnitudes were calibrated using nearby USNO-B1.0 stars (R2 magnitudes). View this GCN Circular online at https://gcn.nasa.gov/circulars/35826. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33677] Fermi GRB 240227A: Global MASTER-Net observations report
by GCN Circulars 28 Feb '24

28 Feb '24

TITLE: GCN CIRCULAR NUMBER: 35825 SUBJECT: Fermi GRB 240227A: Global MASTER-Net observations report DATE: 24/02/28 04:30:39 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240227A ( Fermi GBM team, GCN 35814) errorbox 48100 sec after notice time and 48133 sec after trigger time at 2024-02-27 18:02:28 UT, with upper limit up to 18.0 mag. Observations started at twilight. The observations began at zenith distance = 32 deg. The sun altitude is -10.2 deg. The galactic latitude b = -39 deg., longitude l = 271 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2387115 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 48163 | 2024-02-27 18:02:28 | MASTER-SAAO | (04h 37m 02.73s , -61d 29m 49.8s) | C | 60 | 17.6 | 48163 | 2024-02-27 18:02:28 | MASTER-SAAO | (04h 55m 01.13s , -61d 40m 45.7s) | C | 60 | 17.3 | 48243 | 2024-02-27 18:03:47 | MASTER-SAAO | (04h 21m 16.28s , -59d 36m 59.5s) | C | 60 | 17.8 | 48243 | 2024-02-27 18:03:47 | MASTER-SAAO | (04h 38m 13.45s , -59d 47m 57.1s) | C | 60 | 17.4 | 48322 | 2024-02-27 18:05:07 | MASTER-SAAO | (04h 21m 36.67s , -63d 25m 43.7s) | C | 60 | 18.0 | 48322 | 2024-02-27 18:05:07 | MASTER-SAAO | (04h 40m 47.01s , -63d 36m 37.9s) | C | 60 | 17.7 | 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/35825. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33676] GRB 240225B: Liverpool Telescope afterglow observations
by GCN Circulars 28 Feb '24

28 Feb '24

TITLE: GCN CIRCULAR NUMBER: 35824 SUBJECT: GRB 240225B: Liverpool Telescope afterglow observations DATE: 24/02/28 00:26:44 GMT FROM: Ben Gompertz at U of Birmingham <b.gompertz(a)bham.ac.uk> B. P. Gompertz (U. Birmingham), D. B. Malesani (DAWN/NBI and Radboud Univ.) report: We observed the position of the optical afterglow (Gompertz et al., GCN 35805; Liu et al., GCN 35812; Malesani et al., GCN 35819; Wise et al., GCN 35820) of GRB 240225B (Nakajima et al., GCN 35796; Joshi et al., GCN 35798; Kawakubo et al., GCN 35811) with the IO:O camera on the 2m robotic Liverpool Telescope (LT). Observations began at 21:37:18 on 2024-02-27, 2.06 days after trigger, and consisted of 15x120 s exposures in the SDSS r filter. We detect the afterglow with an AB magnitude of r = 20.04 +/- 0.05, calibrated against nearby SDSS stars and not corrected for foreground extinction. Between this epoch and the initial detection by GOTO (Gompertz et al., GCN 35805), the afterglow is well described by a power-law decay with an index of 0.8, which is consistent with the magnitudes reported by NOT (Malesani et al., GCN 35819) and LT (Wise et al., GCN 35820), though under-predicts those reported by Nanshan/HMT (Liu et al., GCN 35812), potentially suggestive of flaring behaviour at the time of their observation. The steepening in the light curve noted in GCN 35819 may be thus due to local variability, rather than a break in the power-law evolution. We note the presence of a faint underlying source at the afterglow position in Legacy Survey archival imaging, which may be the host galaxy of GRB 240225B. View this GCN Circular online at https://gcn.nasa.gov/circulars/35824. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33675] Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
by GCN Circulars 27 Feb '24

27 Feb '24

TITLE: GCN CIRCULAR NUMBER: 35823 SUBJECT: Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up DATE: 24/02/27 19:08:13 GMT FROM: Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy - MPC Code C82 <osservatorionastroverde(a)gmail.com> TITOLO: Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy in a large collaboration with: M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy), B. De Simone (Universita' degli Studi Di Salerno) AAVSO - American Association of Variable Star Observers. UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili. AstroCampania Associazione. report: Following the Swift trigger no. 1186959 (GCN 34537), using the 24 Inch RC Optical Ritchey-Chretien Reflector telescope and the Apogee Aspen CG16M camera of the Madrona Peak Observatory connected to the AAVSONet network, we obtained a series of B,V,R images of the transient approximately 6 months after the first detection. The images were measured with the VPhot AAVSO software, using the APASS catalogue. The photometry obtained on 19/23/25 February 2024 are as follows: with the following photometry: JD Mag Filter 2460363.97895 15.830 V 2460363.97781 15.987 V 2460359.99249 15.864 V 2460359.99139 15.837 V JD Mag Filter 2460365.97083 15.713 R 2460363.98126 15.552 R 2460363.98014 15.535 R 2460359.99473 15.530 R 2460359.99362 15.512 R JD Mag Filter 2460363.97611 15.230 B 2460363.97427 16.275 B 2460359.98979 16.096 B 2460359.98799 16.131 B The magnitudes are calibrated with stars of the APASS catalog are not corrected for the expected Galactic extinction. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/35823. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33674] Swift Trigger 1217799 is not a GRB
by GCN Circulars 27 Feb '24

27 Feb '24

TITLE: GCN CIRCULAR NUMBER: 35822 SUBJECT: Swift Trigger 1217799 is not a GRB DATE: 24/02/27 18:09:28 GMT FROM: Jamie Kennea at Penn State <jak51(a)psu.edu> J. A. Kennea (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: Swift BAT Trigger 1217799 which occurred as 16:08:47UT on February 27, 2024 is due to a star tracker loss-of-lock, and is not an astrophysical event. View this GCN Circular online at https://gcn.nasa.gov/circulars/35822. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33673] IPN triangulation of GRB 240227A (short)
by GCN Circulars 27 Feb '24

27 Feb '24

TITLE: GCN CIRCULAR NUMBER: 35821 SUBJECT: IPN triangulation of GRB 240227A (short) DATE: 24/02/27 16:50:22 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi GBM team, E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report: The short-duration GRB 240227A (Fermi-GBM detection: The Fermi GBM team, GCN 35814) was detected by Fermi (GBM trigger 730701620), Konus-Wind, and INTEGRAL (SPI-ACS) at about 16815 s UT (04:40:15). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 18.683 (01h 14m 44s) -34.040 (-34d 02' 23") Corners: 19.224 (01h 16m 54s) -35.743 (-35d 44' 35") 18.820 (01h 15m 17s) -32.316 (-32d 18' 58") 18.123 (01h 12m 29s) -32.337 (-32d 20' 15") 18.499 (01h 14m 00s) -35.765 (-35d 45' 54") --------------------------------------------- The error box area is 2.02 sq. deg, and its maximum dimension is 3.53 deg (the minimum one is 35 arcmin). The Sun distance was 43 deg. This localization may be improved. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB240227_T16812/IPN The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. View this GCN Circular online at https://gcn.nasa.gov/circulars/35821. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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