//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31260 SUBJECT: MAXI GRB211218.04: Global MASTER-Net observations report DATE: 21/12/18 03:51:25 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, T.Pogrosheva, E.Minkina, A.Chasovnikov, V.Topolev, V.Grinshpun, 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 (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (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) started inspect of the MAXI GRB211218.04 (trigger No 566013095,09h 09m 06.72s , -04d 06m 36.0s, R=1) errorbox 8135 sec after trigger time at 2021-12-18 03:17:09 UT, with upper limit up to 18.3 mag. The observations began at zenith distance = 70 deg. The sun altitude is -32.8 deg. MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) started inspect of the MAXI GRB211218.04 errorbox 19 sec after notice time and 8221 sec after trigger time at 2021-12-18 03:18:35 UT, with upper limit up to 17.6 mag. The observations began at zenith distance = 36 deg. The sun altitude is -58.4 deg. The galactic latitude b = 28 deg., longitude l = 235 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1818127 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 8226 | 2021-12-18 03:17:09 | MASTER-OAFA | (09h 08m 40.94s , -04d 42m 54.3s) | C | 180 | 17.1 | 8312 | 2021-12-18 03:18:35 | MASTER-IAC | (09h 07m 36.35s , -03d 57m 06.9s) | P- | 180 | 17.3 | 8425 | 2021-12-18 03:20:29 | MASTER-OAFA | (09h 08m 38.08s , -04d 41m 08.9s) | C | 180 | 17.2 | 8512 | 2021-12-18 03:21:55 | MASTER-IAC | (09h 07m 37.32s , -03d 56m 10.9s) | P- | 180 | 17.5 | 8624 | 2021-12-18 03:23:48 | MASTER-OAFA | (09h 08m 38.25s , -04d 42m 58.1s) | C | 180 | 17.4 | 8712 | 2021-12-18 03:25:15 | MASTER-IAC | (09h 07m 41.99s , -03d 57m 13.3s) | P- | 180 | 17.6 | 8824 | 2021-12-18 03:27:07 | MASTER-OAFA | (09h 08m 40.94s , -04d 41m 10.4s) | C | 180 | 17.6 | 9004 | 2021-12-18 03:27:07 | MASTER-OAFA | (09h 08m 40.94s , -04d 41m 10.4s) | C | 540 | 18.3 | Coadd 8912 | 2021-12-18 03:28:35 | MASTER-IAC | (09h 07m 36.10s , -03d 58m 14.8s) | P- | 180 | 17.6 | 9029 | 2021-12-18 03:30:32 | MASTER-OAFA | (09h 08m 36.24s , -04d 42m 01.0s) | C | 180 | 17.6 | 9228 | 2021-12-18 03:33:52 | MASTER-OAFA | (09h 08m 35.95s , -04d 41m 00.3s) | C | 180 | 17.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31261 SUBJECT: GRB 211218A, MAXI J0909-041: MAXI/GSC detection DATE: 21/12/18 05:17:50 GMT FROM: Hitoshi Negoro at Nihon U R. Uematsu (Kyoto U.), H. Negoro (Nihon U.), M. Serino (AGU), M. Nakajima, K. Kobayashi, K. Asakura, K. Seino (Nihon U.), T. Mihara, T. Tamagawa, J. Li, M. Matsuoka (RIKEN), T. Sakamoto, S. Sugita, K. Komachi, H. Hiramatsu, A. Yoshida (AGU), Y. Tsuboi, W. Iwakiri, H. Kawai, Y. Okamoto, S. Kitakoga (Chuo U.), M. Shidatsu, M. Iwasaki (Ehime U.), N. Kawai, M. Niwano, R. Hosokawa, Y. Imai, N. Ito, Y. Takamatsu (Tokyo Tech), S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka, M. Kurihara (JAXA), Y. Ueda, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake, Y. Goto, K. Inaba (Kyoto U.), H. Tsunemi (Osaka U.), M. Yamauchi, Y. Nonaka, T. Sato, R. Hatsuda, R. Fukuoka (Miyazaki U.), T. Kawamuro (UDP/NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC) report on behalf of the MAXI team: The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 01:01:29 UT 2021 December 18. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (137.278 deg, -4.110 deg) = (09 09 06, -04 06 36) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.42 deg and 0.38 deg, respectively. The roll angle of long axis from the north direction is 62.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 118 +- 31 mCrab (4.0-10.0keV, 1 sigma error). Without assumptions on the source constancy, we obtain a rectangular error box for the transient source with the following corners: (R.A., Dec) = (135.984, -5.236) deg = (09 03 56, -05 14 09) (J2000) (R.A., Dec) = (136.566, -5.656) deg = (09 06 15, -05 39 21) (J2000) (R.A., Dec) = (138.302, -3.262) deg = (09 13 12, -03 15 43) (J2000) (R.A., Dec) = (137.722, -2.843) deg = (09 10 53, -02 50 34) (J2000) There was no significant excess flux in the previous transit at 12/17 23:28 UT and in the next transit at 12/18 02:34 UT with an upper limit of 20 mCrab for each. Finally, we note that due to the poor statistics, we can not confirm that this event is a GRB. Therefore, we also name the source MAXI J0909-041. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31278 SUBJECT: GRB 211218A: MITSuME Akeno optical upper limits DATE: 21/12/22 11:58:51 GMT FROM: Yuri Imai at Tokyo Inst of Tech Y. Imai, R. Hosokawa, K. L. Murata, M. Niwano, Y. Takamatsu, N. Ito, R. Yamaguchi, R. Noto, S. Sato, M. Takaku, Y. Yatsu, and N. Kawai (TokyoTech) report on behalf of the MITSuME collaboration: We performed tiling observations for the MAXI/GSC error region of GRB 211218A, MAXI J0909-041 (R. Uematsu et al. GCN Circular #31261, V. Lipunov et al. GCN Circular #31260) with an optical tri-color (g', Rc, and Ic) camera attached to the MITSuME 50 cm telescope Akeno. The follow up observation started at 2021-12-18 13:35:14 UT, 12.6 hours after the trigger. Our tiling observation covered almost ~70% of the MAXI/GSC error region (GCN Circular #31261). Comparing our co-added images with the GSC2.3 catalog, we found no optical transients in the observed region. The 5-sigma upper limits of the co-added images are listed below. Field num. | center position(R.A., Dec.) | size of field(R.A.(arcmin) x Dec.(arcmin)) | 5-sigma upper limit | MID-UT(UT) | exposure time(sec) ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Field 00 | 9:08:47, -4:06:36 | 27.1 x 24.7 | g'>18.2, Rc>19.0, Ic>18.7 | 2021-12-18 17:57:09 | 360.0 Field 01 | 9:08:01, -4:22:05 | 26.6 x 26.5 | g'>18.3, Rc>19.1, Ic>18.7 | 2021-12-18 17:19:28 | 390.0 Field 02 | 9:09:42, -4:17:55 | 26.4 x 26.5 | g'>18.2, Rc>19.0, Ic>18.6 | 2021-12-18 17:45:57 | 330.0 Field 03 | 9:09:01, -4:31:20 | 27.4 x 24.2 | g'>18.2, Rc>19.0, Ic>18.6 | 2021-12-18 17:37:16 | 330.0 Field 04 | 9:07:45, -3:55:46 | 26.0 x 24.3 | g'>18.3, Rc>19.2, Ic>18.8 | 2021-12-18 16:58:53 | 450.0 Field 05 | 9:07:04, -4:08:57 | 26.5 x 27.5 | g'>17.9, Rc>18.7, Ic>18.4 | 2021-12-18 15:49:39 | 240.0 Field 06 | 9:09:26, -3:51:26 | 26.2 x 25.5 | g'>18.2, Rc>18.9, Ic>18.6 | 2021-12-18 17:24:50 | 360.0 Field 07 | 9:07:20, -4:34:20 | 26.5 x 26.1 | g'>18.0, Rc>18.7, Ic>18.4 | 2021-12-18 17:04:52 | 240.0 Field 08 | 9:10:28, -4:03:20 | 26.6 x 26.5 | g'>18.3, Rc>19.2, Ic>18.8 | 2021-12-18 16:49:06 | 540.0 Field 09 | 9:08:17, -4:47:13 | 26.4 x 26.7 | g'>18.1, Rc>18.9, Ic>18.5 | 2021-12-18 17:33:11 | 300.0 Field 10 | 9:08:29, -3:40:30 | 26.5 x 25.1 | g'>18.3, Rc>19.0, Ic>18.7 | 2021-12-18 17:11:30 | 390.0 Field 11 | 9:06:22, -4:25:47 | 25.8 x 26.1 | g'>18.2, Rc>19.1, Ic>18.7 | 2021-12-18 16:00:21 | 480.0 Field 12 | 9:10:10, -3:37:09 | 26.3 x 26.7 | g'>18.0, Rc>18.9, Ic>18.6 | 2021-12-18 16:24:58 | 300.0 Field 13 | 9:06:39, -4:50:05 | 26.4 x 26.6 | g'>17.9, Rc>18.8, Ic>18.4 | 2021-12-18 15:17:23 | 270.0 Field 14 | 9:11:06, -3:48:44 | 26.6 x 26.5 | g'>18.1, Rc>18.8, Ic>18.4 | 2021-12-18 17:11:04 | 210.0 Field 15 | 9:09:11, -3:27:56 | 26.0 x 26.9 | g'>18.1, Rc>19.0, Ic>18.6 | 2021-12-18 16:13:00 | 330.0 Field 16 | 9:07:35, -5:00:29 | 27.3 x 27.6 | g'>17.7, Rc>18.5, Ic>18.3 | 2021-12-18 15:36:49 | 180.0 Field 17 | 9:05:40, -4:40:29 | 27.2 x 26.4 | g'>18.0, Rc>18.8, Ic>18.6 | 2021-12-18 16:07:28 | 330.0 Field 18 | 9:10:52, -3:22:30 | 26.4 x 26.5 | g'>18.0, Rc>18.9, Ic>18.5 | 2021-12-18 15:30:13 | 300.0 Field 19 | 9:11:49, -3:34:14 | 26.6 x 26.5 | g'>18.0, Rc>18.7, Ic>18.4 | 2021-12-18 16:57:19 | 180.0 Field 20 | 9:05:56, -5:04:58 | 26.5 x 26.6 | g'>18.1, Rc>19.0, Ic>18.6 | 2021-12-18 17:02:01 | 420.0 Field 21 | 9:09:48, -3:03:38 | 28.5 x 28.6 | g'>17.1, Rc>17.8, Ic>17.4 | 2021-12-18 20:31:34 | 60.0 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- We used PS1 catalog for flux calibration. 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, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).