January 2025 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 36957] GRB 250114B : MITSuME Akeno optical afterglow candidate detection
by GCN Circulars 15 Jan '25

15 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38950 SUBJECT: GRB 250114B : MITSuME Akeno optical afterglow candidate detection DATE: 25/01/15 10:30:38 GMT FROM: Mahito Sasada at Tokyo Institute of Technology <sasada(a)hp.phys.titech.ac.jp> M. Sasada, I. Takahashi, H. Hagio, Y. Kubo, N. Higuchi, H. Seki, S. Joshima, Y. Yatsu and N. Kawai (Science Tokyo) report on behalf of the MITSuME collaboration: We observed the field of GRB 250114B (Gotz et al. GCN 38938; Evans et al. GCN 38941) with the optical three-color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50-cm telescope Akeno. The observation started at 2025-01-14 13:16:36.51 UT (60 seconds after the INTEGRAL trigger). We stacked the images with good conditions. Then we detected a point source in the Rc- and Ic-band images within the circle of INTEGRAL uncertainty area (Gotz et al. GCN 38938). The source position is R.A. = 48.8582 deg and Dec. = -2.2936 deg, which is consistent with the 2nd X-ray source position of R.A. = 48.8582 deg and Dec. = -2.2940 deg detected by XRT within 1 arcsec (Evans et al. GCN 38941; Williams et al. GCN 38949). Here we report upper limits of the observations, and magnitudes of the source as follows. T0+[sec] | MID-UT | T-EXP[sec] | 5-sigma limits and magnitudes ------------------------------------------------------------------------------------------------ 399 | 2025-01-14 13:22:16.31 | 480 | g'>18.0, Rc=18.1+/-0.1, Ic=17.6+/-0.1 2232 | 2025-01-14 13:52:49.03 | 2460 | g'>18.6, Rc=19.4+/-0.2, Ic=19.1+/-0.2 ------------------------------------------------------------------------------------------------ T0+ : Elapsed time after the trigger T-EXP: Total Exposure time We used the PS1 catalog for flux calibration. The catalog magnitudes in PS1 g, r and i bands were converted to our g', Rc and Ic band magnitudes following Tonry et al. (2012), Table 6. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ; https://github.com/MNiwano/Eclaire). View this GCN Circular online at https://gcn.nasa.gov/circulars/38950. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36956] GRB 250114B: Swift-XRT observations
by GCN Circulars 15 Jan '25

15 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38949 SUBJECT: GRB 250114B: Swift-XRT observations DATE: 25/01/15 10:01:45 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> M. A. Williams (PSU), S. Dichiara (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the INTEGRAL-detected burst GRB 250114B, collecting 5.3 ks of Photon Counting (PC) mode data between T0+11.3 ks and T0+44.6 ks. One uncatalogued X-ray source has been detected within the estimated 3-sigma INTEGRAL error region (197 arcsec), it is below the RASS limit and shows no definitive signs of fading. Therefore, at the present time we cannot confirm this as the afterglow. Details of this source are given below: Source 2: RA (J2000.0): 48.8582 = 03:15:25.96 Dec (J2000.0): -2.2940 = -02:17:38.2 Error: 7.6 arcsec (radius, 90% conf.) Count-rate: (2.62 [+1.04, -0.84])e-3 ct s^-1 Distance: 81 arcsec from INTEGRAL position. Flux: (1.33 [+0.53, -0.43])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Two uncatalogued sources were also detected too far from the GRB position to be likely afterglow candidates. The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021756. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38949. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36955] GRB 250114A: LCO optical counterpart detection.
by GCN Circulars 15 Jan '25

15 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38948 SUBJECT: GRB 250114A: LCO optical counterpart detection. DATE: 25/01/15 04:57:30 GMT FROM: ankur ghosh at CAPP, University of Johannesburg <ghosh.ankur1994(a)gmail.com> Ankur Ghosh, Soebur Razzaque (CAPP, University of Johannesburg), Alexander Moskvitin, Yulia Sotnikova (SAO RAS), Naveen Dukiya (ARIES), Rahul Gupta (NASA GSFC) on behalf of a larger collaboration. We observed the field of the GRB 250114A triggered by Swift (Klingler et al., GCN 38927) in V, r filter of the 1-meter Sinistro telescope at the Las Cumbres Observatory Global Telescope (LCOGT) node located at South African Astronomical Observatory (SAAO). The 1-m Sinistro telescope is equipped with a 4K x 4K CCD (FOV: 26 x 26 arcmin, scale: 0.39 arcsec/pixel). Observations began on January 14, 2025, starting from 6.06 hours after the GRB trigger. We clearly detect the optical transient (OT) reported by GCNs (Beardmore et al., GCN 38936, An et al., GCN 38929; Malesani & Izzo, GCN 38930; Francile et al., GCN 38931; Brivio et al., GCN 38933, Malesani et al., GCN 38934, Pérez-Fournon & Poidevin, GCN 38943) in our V, r band image. The optical afterglow detected in our images is consistent with the UVOT coordinates (Klingler et al., GCN 38927). |Date| |UTstart| |t-T0 (hours)| |Exp (sec)| |Filter| |Magnitude| -------------------------------------------------------------------------------------------------- 2025-01-14 13:36:54.720 6.06 1 x 1200 V V = 21.88 +/- 0.52 2025-01-14 14:11:39.552 6.64 1 x 1200 r r = 22.01 +/- 0.35 -------------------------------------------------------------------------------------------------- The field was calibrated against nearby APASS stars, with magnitudes converted using Lupton (2005) equations, and has not been corrected for Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/38948. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36954] GRB 250114B: OHP/T193 optical upper limit
by GCN Circulars 14 Jan '25

14 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38947 SUBJECT: GRB 250114B: OHP/T193 optical upper limit DATE: 25/01/14 22:47:18 GMT FROM: Benjamin Schneider at MIT <bschn(a)mit.edu> B. Schneider (LAM), C. Adami (LAM/Pytheas/AMU), S. Basa (LAM/OHP/Pytheas/AMU), E. Le Floc'h (CEA), A. Saccardi (CEA), D. Turpin (CEA) report on behalf of a larger collaboration: We observed the field of the INTEGRAL GRB 250114B (Gotz et al., GCN 38938) with the T193cm telescope at the Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. We obtained a total of 61 minutes (1x300s + 4x180s + 11x240s) in the i-band using the red MISTRAL setting from 2025-01-14T18:08 to 2025-01-14T19:29 (mid-time 5.6h after the trigger). In the stacked image, we do not detect any new source at the XRT #2 source position (Evans et al., GCN 38941) or within the INTEGRAL error circle (Gotz et. al., GCN 38938) down to the following 5-sigma limit: i > 20.88 mag (AB) The photometric calibration was performed using nearby stars from the PanSTARRS catalog. We acknowledge the excellent support from Observatoire de Haute-Provence, in particular Jean Balcaen, Orlagh Creevey and Flavien Kiefer. View this GCN Circular online at https://gcn.nasa.gov/circulars/38947. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36953] GRB 250114A: GRANDMA/TAROT optical afterglow detection
by GCN Circulars 14 Jan '25

14 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38946 SUBJECT: GRB 250114A: GRANDMA/TAROT optical afterglow detection DATE: 25/01/14 21:01:29 GMT FROM: Sarah Antier at OCA <sarah.antier(a)oca.eu> S. Antier (OCA/ICJLAB), A. Klotz (IRAP), D. Akl (AUS), S. Karpov (FZU), M. Coughlin (UMN), C. Limonta, M. Boer, Q. Andre, A. Durroux (OCA), C. Andrade (UMN), P. Hello (IJCLAB), P-A Duverne (APC), T. Pradier (Unistra/IPHC), D. Turpin (CEA-Saclay/Irfu), N. Guessoum (AUS) on behalf of the GRANDMA collaboration: We observed the field of GRB 250114A, detected by Swift (Klingler et al., GCN 38927) using TAROT/TCH. Observations began 1 min after T0 without filter, and we took a series of one trailed image lasting 60s and then 5x30s. We detected the optical afterglow candidate in all images. We measured the decaying flux from 15.4 +/- 0.2 r-mag after the first minute, 16.3 +/-0.1 r-mag after the second minute, and 17.4 +/- 0.2 r-mag 5 minutes post T0. The first 60s trailed image was analysed using techniques from Klotz et al., 2006, A&A 451, L39. The data from 2 to 5 min was reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022), using Skymapper. The light curve and its measurements can be found at : https://skyportal-icare.ijclab.in2p3.fr/public/sources/GRB250114 Our measurements are compatible with GCNs 38927, 38929, 38930, 38933, 38934, 38943. GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/). View this GCN Circular online at https://gcn.nasa.gov/circulars/38946. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36952] GRB 250114A: Swift-XRT refined Analysis
by GCN Circulars 14 Jan '25

14 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38945 SUBJECT: GRB 250114A: Swift-XRT refined Analysis DATE: 25/01/14 19:41:44 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> S. Dichiara (PSU), J.A. Kennea (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB), C. Salvaggio (INAF-OAB), D.N. Burrows (PSU) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 8.6 ks of XRT data for GRB 250114A, from 117 s to 28.1 ks after the BAT trigger. The data comprise 317 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 late-time light curve (from T0+4.6 ks) can be modelled with an initial rise, with a power-law index of alpha=-0.94 (+1.18, -0.25), followed by a break at T+8035 s to an alpha of 1.32 (+0.31, -0.29). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.09 (+/-0.03). The best-fitting absorption column is 1.8 (+/-0.9) x 10^22 cm^-2, at a redshift of 4.732, in addition to the Galactic value of 5.1 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.87 (+0.14, -0.13) and a best-fitting absorption column of 1.0 (+2.2, -1.0) x 10^22 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.6 x 10^-11 (4.1 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 5.1 x 10^20 cm^-2 Intrinsic column: 1.0 (+2.2, -1.0) x 10^22 cm^-2 at z=4.732 Photon index: 1.87 (+0.14, -0.13) If the light curve continues to decay with a power-law decay index of 1.32, the count rate at T+24 hours will be 6.8 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.4 x 10^-13 (2.8 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01281241. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38945. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36951] Integral GRB250114.55: Global MASTER-Net observations report
by GCN Circulars 14 Jan '25

14 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38944 SUBJECT: Integral GRB250114.55: Global MASTER-Net observations report DATE: 25/01/14 18:57:44 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) 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) was pointed to the Integral GRB250114.55 (trigger No 11025,03h 15m 27.69s , -02d 18m 51.9s, R=0.053) errorbox 19302 sec after notice time and 19352 sec after trigger time at 2025-01-14 18:38:09 UT, with upper limit up to 17.6 mag. Observations started at twilight. The observations began at zenith distance = 30 deg. The sun altitude is -10.0 deg. The galactic latitude b = -47 deg., longitude l = 184 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2743271 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 19383 | MASTER-SAAO | C | 60 | 17.1 | 19522 | MASTER-SAAO | C | 180 | 16.8 | 19722 | MASTER-SAAO | C | 180 | 17.1 | 19921 | MASTER-SAAO | C | 180 | 17.6 | 20123 | MASTER-SAAO | C | 180 | 17.6 | 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/38944. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36950] GRB 250114A: LCOGT optical afterglow i-band detection
by GCN Circulars 14 Jan '25

14 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38943 SUBJECT: GRB 250114A: LCOGT optical afterglow i-band detection DATE: 25/01/14 17:01:56 GMT FROM: Ismael Perez-Fournon at Instituto de Astrofisica de Canarias <ipf(a)iac.es> I. Pérez-Fournon and F. Poidevin (IAC and ULL) We observed the field of GRB 250114A, detected by Swift BAT, XRT, and UVOT (Klingler et al., GCN 38927; Beardmore et al., GCN 38936) using one of the Las Cumbres Observatory global telescope network (LCOGT) 1-m telescopes, equipped with Sinistro cameras, at the LCOGT node at Siding Spring Observatory (Australia). The observation, a single 600-sec exposure in the SDSS i' filter, started at 2025-01-14 13:59:32 UT, i.e. ~ 6.44 hr after the Swift BAT trigger. The optical afterglow is detected at a position consistent with the UVOT coordinates (Klingler et al., GCN 38927). Me measure a magnitude of i' = 20.17 +/- 0.22, calibrated against PanSTARRS DR2 stars and not corrected for Galactic extinction. Other groups have reported optical and near-IR detections of the afterglow: An et al. (GCN 38929), Malesani and Izzo (GCN 38930), Brivio et al. (GCN 38933) and Malesani et al. (GCN 38934). A redshift of z = 4.732 has been reported by Malesani et al. (GCN 38934). This work makes use of observations from the Las Cumbres Observatory global telescope network (LCOGT observing programme IAC2024B-004, SGLF). View this GCN Circular online at https://gcn.nasa.gov/circulars/38943. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36949] GRB 250114B : GIT optical upper limit
by GCN Circulars 14 Jan '25

14 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38942 SUBJECT: GRB 250114B : GIT optical upper limit DATE: 25/01/14 16:28:42 GMT FROM: V. Swain at IIT Bombay <vishwajeet.s(a)iitb.ac.in> M. Goyal, A.P. Saikia, V. Swain, T. Mohan, V. Bhalerao (IITB), G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team: We observed the field of INTEGRAL GRB 250114B (Gotz et. al., GCN 38938) with 0.7m GROWTH-India Telescope (GIT) in r' filter. We started the observation at 2025-01-14 14:43:01 UT, i.e., 1.46 hours after the INTEGRAL trigger. We did not detect any new source in our stacked image within the uncertainty region reportedd in GCN 38938. The obtained upper limit is as follows: | MJD (mid) | Filter | Exposure (s) | Limiting Magnitude (AB) | | ----------------- |------- | ------------------ | -------------- | | 60689.62099 | r' | 3 x 300 | 20.3 | The measurement is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction. The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/. View this GCN Circular online at https://gcn.nasa.gov/circulars/38942. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36948] GRB 250114B: Swift ToO observations
by GCN Circulars 14 Jan '25

14 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38941 SUBJECT: GRB 250114B: Swift ToO observations DATE: 25/01/14 16:26:10 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the INTEGRAL GRB 250114B. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021756 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the INTEGRAL event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38941. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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