//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29580 SUBJECT: Integral GRB210227.19: Global MASTER-Net OT detection DATE: 21/02/27 04:56:46 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, A.V. Krylov, I. Gorbunov, D. Vlasenko, F. Balakin Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University R. Podesta, Carlos Lopez and F. Podesta Observatorio Astronomico Felix Aguilar (OAFA) A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk K. Ivanov, O. Gres, N.M. Budnev, S.Yazev, O. Chuvalaev, V. Poleshchuk Irkutsk State University D. Buckley, S. Potter, A. Kniazev, M. Kotze South African Astronomical Observatory R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the GRB210227.19 42 sec after notice time and 52 sec after trigger time at 2021-02-27 04:34:46 UT. On our 4-th (30s exposure) set , obtained 157 sec after tigger time at 2021-02-27 04:36:30 UT, we found 1 optical transient within Integral error-box (ra=84.7625 dec=17.8122 r=0.05) brighter than 14.5. T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|------- 172 2021-02-27 04:36:30 30 (05h 39m 11.68s , +17d 49m 09.6s) 13.1 The 5-sigma upper limit has been about 14.5mag The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29581 SUBJECT: Integral GRB210227.19: Global MASTER-Net observations report DATE: 21/02/27 04:57:06 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), 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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Integral GRB210227.19 (trigger No 9020,05h 39m 03.41s , +17d 48m 45.2s, R=0.0488333) errorbox 41 sec after notice time and 52 sec after trigger time at 2021-02-27 04:34:46 UT, with upper limit up to 15.0 mag. The observations began at zenith distance = 85 deg. The sun altitude is -50.5 deg. The galactic latitude b = -6 deg., longitude l = 189 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1556892 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 58 | MASTER-OAFA | C | 10 | 14.7 | 91 | MASTER-OAFA | C | 10 | 14.6 | 128 | MASTER-OAFA | C | 20 | 14.8 | 172 | MASTER-OAFA | C | 30 | 15.0 | 226 | MASTER-OAFA | C | 40 | 15.0 | 371 | MASTER-OAFA | C | 70 | 14.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29582 SUBJECT: Integral GRB210227.20: Global MASTER-Net observations report DATE: 21/02/27 05:19:08 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), 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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Integral GRB210227.20 (trigger No 140092,06h 23m 30.88s , +07d 53m 32.5s, R=0.052) errorbox 139 sec after notice time and 146 sec after trigger time at 2021-02-27 04:47:09 UT, with upper limit up to 17.5 mag. The observations began at zenith distance = 73 deg. The sun altitude is -50.6 deg. The galactic latitude b = -2 deg., longitude l = 203 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1556899 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 162 | MASTER-OAFA | C | 30 | 16.5 | 207 | MASTER-OAFA | C | 120 | 17.2 | Coadd 216 | MASTER-OAFA | C | 40 | 16.6 | 281 | MASTER-OAFA | C | 50 | 16.8 | 356 | MASTER-OAFA | C | 60 | 16.8 | 446 | MASTER-OAFA | C | 240 | 17.5 | Coadd 445 | MASTER-OAFA | C | 80 | 16.9 | 555 | MASTER-OAFA | C | 100 | 17.0 | 684 | MASTER-OAFA | C | 120 | 17.0 | 839 | MASTER-OAFA | C | 150 | 17.0 | 1023 | MASTER-OAFA | C | 180 | 17.1 | 1223 | MASTER-OAFA | C | 180 | 17.0 | 1423 | MASTER-OAFA | C | 180 | 17.0 | 1623 | MASTER-OAFA | C | 180 | 16.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29585 SUBJECT: Integral GRB210227.19: MASTER OT retraction DATE: 21/02/27 14:54:54 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy,N.Tiurina,P.Balanutsa,F.Balakin, V.Vladimirov, A.Kuznetsov,K.Zhirkov,D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, A.Chasovnikov,A.Pozdnyakov,V.Topolev, D.Cheryasov(Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico FelixAguilar OAFA), R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) MASTER collaboration reports: MASTER OT, publishied in GCN 29580, is not new optical source, but is known bright star (error in coordinates detection was from bad weather conditions) We apologize for any confusion this error may have caused. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29586 SUBJECT: Integral GRB210227.20: Global MASTER-Net observations report DATE: 21/02/27 18:57:06 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), 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-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 GRB210227.20 (trigger No 74556,04h 55m 14.80s , +16d 48m 23.3s, R=0.0483333) errorbox 48576 sec after notice time and 48583 sec after trigger time at 2021-02-27 18:13:36 UT, with upper limit up to 19.3 mag. Observations started at twilight. The observations began at zenith distance = 50 deg. The sun altitude is -12.7 deg. The galactic latitude b = -16 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=1556893 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 48674 | MASTER-SAAO | C | 180 | 18.5 | 49074 | MASTER-SAAO | C | 180 | 19.3 | 49636 | MASTER-SAAO | C | 180 | 19.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.