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

[vsnet-grb-info 33840] GRB 240328B: Fermi GBM Final Real-time Localization
by GCN Circulars 28 Mar '24

28 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35987 SUBJECT: GRB 240328B: Fermi GBM Final Real-time Localization DATE: 24/03/28 19:19:46 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 19:09:10 UT on 28 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240328B (trigger 733345755.665982 / 240328798). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 223.4, Dec = -20.1 (J2000 degrees, equivalent to J2000 14h 53m, -20d 06'), with a statistical uncertainty of 11.6 degrees. The angle from the Fermi LAT boresight is 78.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240328798/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240328798/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240328798/… View this GCN Circular online at https://gcn.nasa.gov/circulars/35987. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33839] GRB 240328A: Fermi GBM Final Real-time Localization
by GCN Circulars 28 Mar '24

28 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35986 SUBJECT: GRB 240328A: Fermi GBM Final Real-time Localization DATE: 24/03/28 12:39:20 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 SHORT GRB At 12:21:22 UT on 28 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240328A (trigger 733321287.517204 / 240328515). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 231.9, Dec = -3.8 (J2000 degrees, equivalent to J2000 15h 27m, -3d 47'), with a statistical uncertainty of 15.9 degrees. The angle from the Fermi LAT boresight is 91.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240328515/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240328515/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240328515/… View this GCN Circular online at https://gcn.nasa.gov/circulars/35986. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33838] IceCube Alert 240327.68: Global MASTER-Net observations report
by GCN Circulars 27 Mar '24

27 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35985 SUBJECT: IceCube Alert 240327.68: Global MASTER-Net observations report DATE: 24/03/27 19:39:43 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-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the IceCube Alert 240327.68 (trigger No 9784024,05h 56m 50.40s , +00d 55m 48.0s, R=1.4) errorbox 10823 sec after notice time and 10876 sec after trigger time at 2024-03-27 19:13:47 UT, with upper limit up to 18.2 mag. The observations began at zenith distance = 73 deg. The sun altitude is -36.5 deg. The galactic latitude b = -11 deg., longitude l = 206 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2408710 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 10967 | 2024-03-27 19:13:47 | MASTER-Kislovodsk | (05h 57m 23.69s , +00d 55m 43.0s) | C | 180 | 17.9 | 10967 | 2024-03-27 19:13:47 | MASTER-Kislovodsk | (05h 53m 38.29s , +01d 16m 16.5s) | C | 180 | 18.2 | 11107 | 2024-03-27 19:17:07 | MASTER-Kislovodsk | (05h 50m 05.31s , +01d 11m 04.6s) | C | 60 | 17.3 | 11107 | 2024-03-27 19:17:07 | MASTER-Kislovodsk | (05h 46m 20.62s , +01d 31m 36.6s) | C | 60 | 17.4 | 11188 | 2024-03-27 19:18:28 | MASTER-Kislovodsk | (06h 05m 19.39s , +01d 12m 31.8s) | C | 60 | 17.1 | 11188 | 2024-03-27 19:18:28 | MASTER-Kislovodsk | (06h 01m 33.66s , +01d 33m 08.1s) | C | 60 | 17.6 | 11268 | 2024-03-27 19:19:48 | MASTER-Kislovodsk | (05h 50m 09.68s , -00d 43m 00.2s) | C | 60 | 17.2 | 11268 | 2024-03-27 19:19:48 | MASTER-Kislovodsk | (05h 46m 26.07s , -00d 22m 31.8s) | C | 60 | 17.5 | 11348 | 2024-03-27 19:21:08 | MASTER-Kislovodsk | (06h 05m 15.84s , -00d 43m 33.2s) | C | 60 | 17.2 | 11348 | 2024-03-27 19:21:08 | MASTER-Kislovodsk | (06h 01m 31.22s , -00d 22m 59.0s) | C | 60 | 17.6 | 11428 | 2024-03-27 19:22:28 | MASTER-Kislovodsk | (05h 50m 36.45s , +03d 04m 24.3s) | C | 60 | 17.1 | 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/35985. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33837] IceCube-240327B - IceCube observation of a high-energy neutrino candidate track-like event
by GCN Circulars 27 Mar '24

27 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35984 SUBJECT: IceCube-240327B - IceCube observation of a high-energy neutrino candidate track-like event DATE: 24/03/27 18:11:03 GMT FROM: Giacomo Sommani at Ruhr-Universität Bochum <gsommani(a)icecube.wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 2024-03-27, at 16:12:30.47 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_BRONZE alert stream. The average astrophysical neutrino purity for Gold alerts is 30%. This alert has an estimated false alarm rate of 2.420 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection. After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/139205_9784024.amon) more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2024-03-27 Time: 16:12:30.47 UT RA: 89.21 (+1.36, -1.55 deg 90% PSF containment) J2000 Dec: 0.93 (+1.23, -1.47 deg 90% PSF containment) J2000 We encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino. Five known gamma-ray sources listed in the Fermi 4FGL-DR4 or 3FHL catalogs are located within the 90% uncertainty region of the event. The nearest one to the neutrino alert position is 4FGL J0555.9+0030, located at RA = 89.00 deg, Dec = 0.51 deg J2000, 0.47 deg away from the best-fit alert position. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu View this GCN Circular online at https://gcn.nasa.gov/circulars/35984. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33836] IceCube-240327A - IceCube observation of a high-energy neutrino candidate track-like event
by GCN Circulars 27 Mar '24

27 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35983 SUBJECT: IceCube-240327A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 24/03/27 13:44:38 GMT FROM: A. Zegarelli at Ruhr University Bochum <azegarelli(a)icecube.wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 2024-03-27 at 11:04:49.50 UT IceCube detected a track-like event with a high probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_GOLD alert stream. The average astrophysical neutrino purity for Gold alerts is 50%. This alert has an estimated false alarm rate of 1.0306 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection. After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/139204_39158985.amon) more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2024-03-27 Time: 11:04:49.50 UT RA: 25.40 (+1.86, -2.36 deg 90% PSF containment) J2000 Dec: 7.78 (+0.69, -0.68 deg 90% PSF containment) J2000 We encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino. No known gamma-ray sources listed in the Fermi 4FGL-DR4 or 3FHL catalogs are located within the 90% uncertainty region of the event. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu View this GCN Circular online at https://gcn.nasa.gov/circulars/35983. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33835] X-ray transient EP 240315a: Second epoch Chandra observations
by GCN Circulars 27 Mar '24

27 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35982 SUBJECT: X-ray transient EP 240315a: Second epoch Chandra observations DATE: 24/03/27 09:06:39 GMT FROM: Andrew Levan at Radboud University <a.levan(a)astro.ru.nl> A.J. Levan (Radboud & Warwick), P.G. Jonker (Radboud), D.B. Malesani (DAWN/NBI & Radboud), N.R. Tanvir (Leicester), B.P. Gompertz (Birmingham), A. Saccardi (GEPI/Obs. de Paris), A. de Ugarte Postigo (CNRS/OCA & LAM), A. Martin-Carrillo (UCD), D. Perley (LJMU), D. Xu (NAOC), G. Tagliaferri (INAF, Brera), J. Palmerio (GEPI/Obs. de Paris)), K.E. Heintz (DAWN/NBI), K. Wiersema (Hertfordshire), M. Grazia Bernardini (INAF, Brera), M. Ferro (INAF, Brera), P. Jakobbson (U. Iceland), P. D’Avanzo (INAF, Brera), R. Salvaterra (INAF, Milan), S. Vergani (GEPI/Obs. de Paris), G. Pugliese (API, Amsterdam), Y. Julakanti (Leicester) report for the Stargate collaboration: We obtained a second epoch of Chandra observations of EP240315a (Zhang et al., GCN 35931; Chen et al., GCN 35951) beginning at 04:34 on 26 March 2024, approximately 10.4 days after the transient detection and 6 days from the first epoch of observations (Levan et al., GCN 35963). A total of 18.5 ks of observations were obtained (compared to 10 ks at the first epoch). At the location of AT2024eju (Srivastav et al. GCN 35932) we do not detect any source. More formally, we identify a single photon at the source location, and set a 2-sigma upper limit of <2.4e-4 count s^-1 at this epoch. The inferred decay rate from 3 days to 10.4 days is steeper than t^-2.1, and suggests a relatively rapid decay. This is consistent with the post-jet break decay rate for a GRB afterglow. We again thank Pat Slane, Vinay Kashyap and the staff of the CXC for their excellent support and rapid scheduling of these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/35982. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33834] Fermi trigger No 733097506: Global MASTER-Net observations report
by GCN Circulars 26 Mar '24

26 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35981 SUBJECT: Fermi trigger No 733097506: Global MASTER-Net observations report DATE: 24/03/26 17:30:56 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-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB240325.92 (trigger No 733097506,01h 55m 00.00s , +01d 54m 00.0s, R=30.45) errorbox 54024 sec after notice time and 54058 sec after trigger time at 2024-03-26 13:12:40 UT, with upper limit up to 14.7 mag. Observations started at twilight. The observations began at zenith distance = 72 deg. The sun altitude is -16.4 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB240325.92 errorbox 65955 sec after notice time and 65989 sec after trigger time at 2024-03-26 16:31:31 UT, with upper limit up to 18.0 mag. Observations started at twilight. The observations began at zenith distance = 62 deg. The sun altitude is -11.9 deg. The galactic latitude b = -57 deg., longitude l = 154 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2406794 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 54088 | 2024-03-26 13:12:40 | MASTER-Tunka | (02h 55m 06.52s , +17d 04m 35.9s) | C | 60 | 13.8 | 54089 | 2024-03-26 13:12:40 | MASTER-Tunka | (02h 53m 52.29s , +16d 28m 26.9s) | C | 60 | 14.7 | 66020 | 2024-03-26 16:31:31 | MASTER-Kislovodsk | (02h 30m 22.81s , +28d 07m 21.0s) | C | 60 | 14.9 | 66261 | 2024-03-26 16:35:32 | MASTER-Kislovodsk | (02h 32m 11.32s , +25d 51m 11.9s) | C | 60 | 16.1 | 66261 | 2024-03-26 16:35:32 | MASTER-Kislovodsk | (02h 27m 55.78s , +26d 12m 05.8s) | C | 60 | 16.4 | 66341 | 2024-03-26 16:36:52 | MASTER-Kislovodsk | (02h 54m 37.58s , +16d 22m 18.5s) | C | 60 | 16.1 | 66341 | 2024-03-26 16:36:52 | MASTER-Kislovodsk | (02h 50m 39.80s , +16d 43m 12.7s) | C | 60 | 16.7 | 66983 | 2024-03-26 16:47:34 | MASTER-Kislovodsk | (02h 34m 50.66s , +27d 45m 12.9s) | C | 60 | 17.2 | 66983 | 2024-03-26 16:47:34 | MASTER-Kislovodsk | (02h 30m 31.07s , +28d 06m 05.3s) | C | 60 | 18.0 | 67223 | 2024-03-26 16:51:34 | MASTER-Kislovodsk | (02h 32m 17.68s , +25d 52m 26.7s) | C | 60 | 17.4 | 67223 | 2024-03-26 16:51:34 | MASTER-Kislovodsk | (02h 28m 03.93s , +26d 13m 16.7s) | C | 60 | 17.9 | 67303 | 2024-03-26 16:52:54 | MASTER-Kislovodsk | (02h 54m 31.95s , +16d 22m 24.3s) | C | 60 | 17.2 | 67303 | 2024-03-26 16:52:54 | MASTER-Kislovodsk | (02h 50m 35.97s , +16d 43m 13.4s) | C | 60 | 17.9 | 67944 | 2024-03-26 17:03:35 | MASTER-Kislovodsk | (02h 34m 44.27s , +27d 45m 18.2s) | C | 60 | 17.3 | 67944 | 2024-03-26 17:03:35 | MASTER-Kislovodsk | (02h 30m 26.14s , +28d 06m 06.7s) | C | 60 | 18.0 | 68185 | 2024-03-26 17:07:36 | MASTER-Kislovodsk | (02h 32m 10.21s , +25d 50m 06.1s) | C | 60 | 16.9 | 68185 | 2024-03-26 17:07:36 | MASTER-Kislovodsk | (02h 27m 58.10s , +26d 10m 51.5s) | C | 60 | 17.6 | 68265 | 2024-03-26 17:08:56 | MASTER-Kislovodsk | (02h 54m 36.53s , +16d 21m 19.8s) | C | 60 | 16.9 | 68265 | 2024-03-26 17:08:56 | MASTER-Kislovodsk | (02h 50m 42.00s , +16d 42m 04.9s) | C | 60 | 17.5 | 68345 | 2024-03-26 17:10:16 | MASTER-Kislovodsk | (02h 51m 38.04s , +12d 34m 19.1s) | C | 60 | 16.8 | 68345 | 2024-03-26 17:10:16 | MASTER-Kislovodsk | (02h 47m 49.51s , +12d 54m 58.2s) | C | 60 | 17.1 | 68425 | 2024-03-26 17:11:37 | MASTER-Kislovodsk | (02h 52m 59.66s , +14d 27m 09.9s) | C | 60 | 17.0 | 68425 | 2024-03-26 17:11:37 | MASTER-Kislovodsk | (02h 49m 08.58s , +14d 47m 49.7s) | C | 60 | 17.5 | 68666 | 2024-03-26 17:15:37 | MASTER-Kislovodsk | (03h 12m 19.95s , +18d 17m 12.4s) | C | 60 | 17.0 | 68666 | 2024-03-26 17:15:37 | MASTER-Kislovodsk | (03h 08m 20.63s , +18d 38m 03.1s) | C | 60 | 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/35981. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33833] X-ray transient EP240315a: e-MERLIN radio observations
by GCN Circulars 26 Mar '24

26 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35980 SUBJECT: X-ray transient EP240315a: e-MERLIN radio observations DATE: 24/03/26 14:45:28 GMT FROM: Gabriele Bruni at INAF <gabriele.bruni(a)inaf.it> G. Bruni (INAF-IAPS), L. Rhodes (Oxford), L. Piro, G. Gianfagna, A.L. Thakur (INAF-IAPS), J. Bright, F. Carotenuto, S. Smartt, R. Fender (Oxford), P. Jonker (Radboud) report: We observed the new Fast X-ray Transient EP240315a (Zhang et al., GCN 35931) with the e-Merlin radio telescope under the projects DD17003 (PI: Piro) and DD17004 (PI: Rhodes) at 5 GHz for a total of ~16 hours using a combination of two runs in two consecutive nights (from ~17:30 UT to ~02.00 UT, on March 20 and 21, 2024). 3C286 was used for flux scale calibration, and 0933-0819 for complex gain, respectively. The beam size was 275x104 milli-arcsec. Data was reduced with the e-MERLIN pipeline and imaged with CASA. The image RMS was 15 uJy/beam. We did not find statistically significant emission at a level above 5-sigma at the position of the optical counterpart (AT2024eju, Srivastav et al., GCN 35932). Thus, we estimated a 5-sigma upper limit of 75 uJy at 5 GHz. Scintillation could be a possible explanation for the large variability with respect to the previous radio detection at the same frequency (Leung et al., GCN 35968). Further e-Merlin observations are planned. We thank the e-Merlin staff for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/35980. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33832] X-ray transient EP240315a: Ondrejov D50 optical limit
by GCN Circulars 26 Mar '24

26 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35979 SUBJECT: X-ray transient EP240315a: Ondrejov D50 optical limit DATE: 24/03/26 11:07:49 GMT FROM: Martin Jelinek at Astro.Inst-AVCR,Ondrejov <martin.jelinek(a)asu.cas.cz> Alzbeta Malenakova, Jan Strobl, Martin Jelinek, Rene Hudec and Cyril Polasek (ASU CAS Ondrejov, CZ), report: We observed the field of the fast X-ray transient EP240315a detected by Einstein Probe (Zhang et al., GCN 35931) and its optical counterpart AT2024eju detected by ATLAS (Srivastav et al., GCN 35932) with the 50 cm robotic telescope (D50) of Ondrejov observatory in Czech Republic. We obtained a set of 120s SDSS-r' exposures starting at 23:03 UT on March 16. We measure the optical limit r' > 21.1 in a combined 26x120s image with a mean time T-T0 27.43h post detection, which is in agreement with other observations at similar epoch (e.g. Chen et al., GCN 35938, Leonini et al., 35944). View this GCN Circular online at https://gcn.nasa.gov/circulars/35979. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33831] Transient EPW20240219aa: REM optical/NIR further observations
by GCN Circulars 26 Mar '24

26 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35978 SUBJECT: Transient EPW20240219aa: REM optical/NIR further observations DATE: 24/03/26 09:04:38 GMT FROM: Matteo Ferro <matteo.ferro(a)inaf.it> M. Ferro, Y.-D. Hu, P. D’Avanzo, R. Brivio, S. Covino, D. Fugazza (INAF-OAB) on behalf of the REM team, report: We observed for a second epoch the field of the transient EPW20240219aa (Zhang et al., ATel 16463; Zhang et al., ATel 16472; Zhang et al., GCN 35773) with the REM 60cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried in the g, r, i, z, H bands, starting on 2024 March 15 at 23:53:40 UT (i.e. 25.73 days after the event), and lasting for about 30 minutes. In order to identify a possible supernova we performed image subtraction between these observations and the first epoch (taken 5.75 days after the event, Ferro et al., GCN 35803). We find no clear transient candidate within the Einstein Probe error circle, nor at the positions of the radio sources reported by Ho et al. (GCN 35788), down to the following 3sigma magnitude upper limits: H > 18.1 (Vega; calibrated against the 2MASS catalogue) r > 19.8 (AB; calibrated against the Pan-STARRS catalogue) View this GCN Circular online at https://gcn.nasa.gov/circulars/35978. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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