//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33081 SUBJECT: Integral GRB221218.34: Global MASTER-Net observations report DATE: 22/12/18 14:57:14 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, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (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), 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), A. Gabovich, V.Yurkov (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) was pointed to the Integral GRB221218.34 (trigger No 141204,23h 22m 36.00s , -04d 15m 38.5s, R=0.0436) errorbox 22820 sec after notice time and 22925 sec after trigger time at 2022-12-18 14:37:57 UT, with upper limit up to 18.5 mag. Observations started at twilight. The observations began at zenith distance = 47 deg. The sun altitude is -10.7 deg. The galactic latitude b = -59 deg., longitude l = 77 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2185335 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 23015 | MASTER-Kislovodsk | C | 180 | 17.8 | 23195 | MASTER-Kislovodsk | C | 540 | 18.5 | Coadd 23216 | MASTER-Kislovodsk | C | 180 | 18.1 | 23417 | MASTER-Kislovodsk | C | 180 | 17.9 | 23617 | MASTER-Kislovodsk | C | 180 | 17.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33082 SUBJECT: GRB 221218A: a long GRB detected by INTEGRAL DATE: 22/12/18 21:56:21 GMT FROM: Sandro Mereghetti at IASF-Milano/INAF S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report: a gamma ray burst lasting about 140 s has been detected by IBAS in the IBIS/ISGRI data at 08:14:10 UT of 2022 December 18. The refined coordinates (J2000) are: R.A.= 350.6495 deg DEC.= -4.2477 deg with an uncertainty of 1 arcmin (90% c.l.). The burst had a peak flux of 1 ph/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range of about 5e-6 erg/cmq. A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33085 SUBJECT: GRB 221218A: KAIT Optical Upper Limit DATE: 22/12/19 18:50:23 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to INTEGRAL GRB 221218A (Mereghetti et al., GCN 33082) starting at 0.78 days after the burst. A total of 23x60s images were obtained in the clear (roughly R) filters. We do not detect any optical afterglow candidate within the IBAS position error circle (Mereghetti et al., GCN 33082), neither in single image, nor in the co-add images. The typical limiting magnitude of our single clear image is about 18.5 mag calibrated to the PS1 catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33086 SUBJECT: GRB 221218A: BOOTES-4/MET and OSN optical upper limits DATE: 22/12/20 08:23:25 GMT FROM: Youdong HU at IAA-CSIC Y.-D. Hu, F. Aceituno, E. Fernandez-Garcia, I. Perez-Garcia, A. J. Castro-Tirado, M. D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga) and D. R. Xiong, Y. F. Fan, J. M. Bai, C. J. Wang, Y. X. Xin, X. H. Zhao (Yunnan Observatories of CAS) on behalf of a larger collaboration, report: Following the detection of GRB 221218A by INTEGRAL (Mereghetti et al. GCNC 33082), we triggered the 0.6m BOOTES-4/MET robotic telescope at Lijiang Astronomical Observatory (China) to follow up starting on Dec. 19 at 12:52:50 UT (~1.2 day post burst). No new source is detected within the IBAS error region (Mereghetti et al. GCNC 33082) in the co-added image (6 x 60 s, clear filter) down to 19.2 mag. Later on, we also triggered the 0.9m OSN telescope in Granada (Spain) starting on Dec. 19 at 18:02:59 UT (~1.4 day post burst). Ten images covering the IBAS error region were taken in the I-band. No optical afterglow is detected in the stacked image down to I=20.1. These results are in agreement with the non-detection reported by Lipunov et al. (GCNC 33081) and Zheng et al. (GCNC 33085). We thank the staff both at Lijiang observatory and OSN for their excellent support. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33087 SUBJECT: GRB 221218A: MITSuME Akeno optical upper limits DATE: 22/12/20 10:21:15 GMT FROM: Ichiro Takahashi at Tokyo Tech I. Takahashi, M. Niwano, R. Hosokawa, K. L. Murata, Y. Imai, N. Ito, S. Sato, N. Higuchi, M. Tateda, M. Sasada, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 221218A (S. Mereghetti et al. GCN Circular #33082, WeiKang Zheng et al. GCN Circular #33085, Y.-D. Hu et al. GCN Circular #33086) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope Akeno. The observation with a series of 60 sec exposures started at 2022-12-18 08:37:35 UT (1405 seconds after the INTEGRAL trigger). We stacked the images with good conditions. We did not detect any uncatalogued sources within the error region (S. Mereghetti et al. GCN Circular #33082). We obtained the 5-sigma limits of the stacked images as follows. T0+[sec] | MID-UT | T-EXP[sec] | 5-sigma limits ------------------------------------------------------------------------------------------------ 1405 | 2022-12-18 08:51:23 | 1140.0 | g'>19.1, Rc>19.0, Ic>18.4 ------------------------------------------------------------------------------------------------ T0+ : Elapsed time after the burst T-EXP: Total Exposure time 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). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33090 SUBJECT: GRB 221218A: 3.6m DOT optical upper limit DATE: 22/12/21 21:44:51 GMT FROM: Rahul Gupta at ARIES, India Rahul Gupta, Amit K. Ror, S. B. Pandey, A. Aryan, A. Ghosh, Dimple, and K. Misra (ARIES) report: We observed the field of GRB 221218A detected by INTEGRAL (Mereghetti et al., GCN 33082) using the 4Kx4K CCD Imager (Pandey et al. 2017, arXiv:1711.05422v1) mounted at the axial port of the 3.6m Devasthal Optical Telescope of ARIES Nainital. We have taken multiple frames having an exposure time of 300 sec in the R filter. We stacked the images after the alignment. We do not find any evidence of an afterglow candidate inside the INTEGRAL error circle, consistent with other non-detections (Lipunov et al., GCN 33081; Zheng et al., GCN 33085; Hu et al., GCN 33086; and Takahashi et al., GCN 33087). We obtained the limiting mag of ~ 22.8 mag at ~ 2.3 days post-detection. Despite early to late time deep optical follow-up observations, the non-detection of the optical counterpart of GRB 221218A indicates the dark nature of the burst, although more detailed analysis is needed to confirm. The limiting magnitudes quoted are not corrected for the Galactic and host extinction in the direction of the burst. Photometric calibration is performed using the standard stars from the USNO-B1.0 catalogue. This circular may be cited. 3.6m Devasthal Optical Telescope (DOT) is the 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.