GRB201223A

This page lists all entries on GRB201223A in GRBweb

Summary Fermi GBM IPN Swift GCN 29158 GCN 29159 GCN 29160 GCN 29161 GCN 29163 GCN 29164 GCN 29165 GCN 29166 GCN 29167 GCN 29168 GCN 29169 GCN 29170 GCN 29171 GCN 29173 GCN 29174 GCN 29176 GCN 29177 GCN 29180 GCN 29201

Summary table
Variable Value Source
GRB_name_Fermi GRB201223749
T0 17:58:06.750 UTC Fermi_GBM
ra 132.7896° Swift
decl 71.1798° Swift
pos_error 5.44e-05° Swift
T90 33.281 s Fermi_GBM
T90_error 25.601 s Fermi_GBM
T90_start 17:58:06.750 UTC Fermi_GBM
fluence 2.10e-06 erg/cm² Fermi_GBM
fluence_error 5.56e-08 erg/cm² Fermi_GBM
T100 48.25 s
GBM_located False
mjd 59206.74868923611 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB201223749
trigger_name bn201223749
ra 132.7858°
decl 71.1792°
pos_error 6.30e+00°
datum 2020-12-23
t_trigger 17:58:25.695 UTC
T90 33.281 s
T90_error 25.601 s
T90_start 17:58:06.750 UTC
fluence 2.10e-06 erg/cm²
fluence_error 5.56e-08 erg/cm²
flux_1024 2.37e+00 erg/cm²/s
flux_1024_error 1.85e-01 erg/cm²/s
flux_1024_time 4.10e+00 erg/cm²/s
flux_64 4.16e+00 erg/cm²/s
flux_64_error 9.84e-01 erg/cm²/s
IPN table
GRB_name GRB201223A
ra 132.8500°
decl 71.1667°
pos_error 5.00e-02°
Swift table
GRB_name GRB201223A
t_trigger 17:58:26 UTC
ra 132.7896°
decl 71.1798°
pos_error 5.44e-05°
T90 29.0 s
fluence 1.30e-06 erg/cm²
GCN 29158 table
GRB_name GRB201223A
GCN_number 29158
Detection_method Swift Det
t_trigger 17:58:26 UTC
ra 132.8490°
decl 71.1740°
Circular_text TITLE: GCN CIRCULAR NUMBER: 29158 SUBJECT: GRB 201223A: Swift detection of a burst with a bright optical counterpart DATE: 20/12/23 18:12:13 GMT FROM: David Palmer at LANL J.D. Gropp (PSU), S. D. Barthelmy (GSFC), J. A. Kennea (PSU), N. J. Klingler (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), B. Sbarufatti (PSU) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 17:58:26 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 201223A (trigger=1014316). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 132.849, +71.174 which is RA(J2000) = 08h 51m 24s Dec(J2000) = +71d 10' 26" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 50 sec. The peak count rate was ~1600 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 17:59:40.7 UT, 73.7 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 132.78615, 71.17926 which is equivalent to: RA(J2000) = 08h 51m 08.68s Dec(J2000) = +71d 10' 45.3" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 75 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 3.13 x 10^20 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 78 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 08:51:09.51 = 132.78963 DEC(J2000) = +71:10:47.4 = 71.17982 with a 90%-confidence error radius of about 0.61 arc sec. This position is 3.8 arc sec. from the center of the XRT error circle. The estimated magnitude is 16.16 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.05. Burst Advocate for this burst is J.D. Gropp (jdg44 AT psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)
GCN 29159 table
GRB_name GRB201223A
GCN_number 29159
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 29159 SUBJECT: GRB 201223A: Nanshan/NEXT early optical afterglow detection DATE: 20/12/23 18:58:50 GMT FROM: Dong Xu at NAOC/CAS Z.P. Zhu (NAOC, HUST), S.Y. Fu, M. Zhang, X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report: We observed the field of GRB 201223A (Gropp et al., GCN 29158) using the NEXT-0.6m optical telescope located at Nanshan, Xinjiang, China. Observations automatically started at 18:01:14 UT on 2020-12-23, i.e., 168 s after the BAT trigger. We obtained a series of 2x40s, 4x60s and 12x90s frames in the Sloan r-filter, and observations are ongoing. An uncatalogued decaying optical transient is detected at the Swift/UVOT position (Gropp et al., GCN 29158), which is thus concluded to be the optical afterglow of burst. The afterglow has r = 15.67 +/- 0.01 mag in our first image, calibrated with nearby PS1 stars. [GCN OPS NOTE(24Dec2020) Per author's request, M. Zhang was added to the author list.]
GCN 29160 table
GRB_name GRB201223A
GCN_number 29160
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 29160 SUBJECT: GRB 201223A: BOOTES-4/MET early optical observation DATE: 20/12/23 19:05:41 GMT FROM: Youdong HU at IAA-CSIC Y.-D. Hu, E. Fernandez-Garcia, M. A. Castro, A. J. Castro-Tirado (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga), S. Guziy (Univ. of Nikolaev) and D. Xiong, Y. Fan, X. Zhao, J. Bai, C. Wang, Y. Xin (Yunnan Nacional Astronomical Observatory) on behalf of a larger collaboration, report: Following the detection of GRB 201223A by Swift (Gropp et al. GCNC 29158), the 0.6m BOOTES-4/MET robotic telescope at Lijiang Astronomical Observatory (China) started to gather images in clear filter starting at 18:01:22 UT (~176 s after trigger). The optical afterglow reported by Swift/UVOT (Gropp et al. GCNC 29158), MASTER (Lipunov et al. GCNC 29157) and Nanshan/NEXT (Zhu et al. GCNC 29159) is detected with a magnitude of 15.7+-0.15. Additional observations are ongoing. We thank the staff at Lijiang observatory for their excellent support.
GCN 29161 table
GRB_name GRB201223A
GCN_number 29161
Detection_method Fermi GBM Det
t_trigger 17:58:25.690 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 29161 SUBJECT: GRB 201223A: Fermi GBM Detection DATE: 20/12/23 23:53:30 GMT FROM: Joshua Wood at MSFC/Fermi-GBM J. Wood (NASA/MSFC) reports on behalf of the Fermi GBM Team: "At 17:58:25.69 UT on 23 December 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 201223A (trigger 630439110 / 201223749) which was also detected by the Swift/BAT and Swift/XRT (Gropp et al. 2020, GCN 29158). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 63 degrees. The GBM light curve shows multiple peaks with a duration (T90) of about 33 s (50-300 keV). The time-averaged spectrum from T0-17 s to T0+13 s is best fit by a Band function with Epeak = 86 +/- 12 keV, alpha = 0.14 +/- 0.38 and beta = -2.6 +/- 0.4. A power law function with an exponential high-energy cutoff fits the spectrum equally well. The power law index is -0.14 +/- 0.24 and the cutoff energy, parameterized as Epeak, is 99 +/- 8 keV. The event fluence (10-1000 keV) in this time interval is (2.1 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+4.1 s in the 10-1000 keV band is 2.4 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN 29163 table
GRB_name GRB201223A
GCN_number 29163
Detection_method Swift-BAT Det
ra 132.7350°
decl 71.1760°
Circular_text TITLE: GCN CIRCULAR NUMBER: 29163 SUBJECT: GRB 201223A: Swift-BAT refined analysis DATE: 20/12/24 01:56:53 GMT FROM: Amy Lien at GSFC S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), J.D. Gropp (PSU), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-239 to T+882 sec from the recent telemetry downlink, we report further analysis of BAT GRB 201223A (trigger #1014316) (Gropp et al., GCN Circ. 29158). The BAT ground-calculated position is RA, Dec = 132.735, 71.176 deg which is RA(J2000) = 08h 50m 56.3s Dec(J2000) = +71d 10' 34.9" with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 53%. The mask-weighted light curve shows a multi-peaked structure that starts at ~T-25 s and ends at ~T+8 s. The main peak occurs at ~T0. T90 (15-350 keV) is 29.0 +- 6.7 sec (estimated error including systematics). The time-averaged spectrum from T-25.18 to T+7.82 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.35 +- 0.13. The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T-0.18 sec in the 15-150 keV band is 1.5 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/1014316/BA/
GCN 29164 table
GRB_name GRB201223A
GCN_number 29164
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 29164 SUBJECT: GRB 201223A: MITSuME Akeno optical observation DATE: 20/12/24 02:08:01 GMT FROM: Ryohei Hosokawa at Tokyo Institute of Technology R. Hosokawa, K. L. Murata, R. Adachi, M. Niwano, F. Ogawa, N. Nakamura, N. Ito, S. Ogata, H. Takamatsu, H. Hara, Y. Yatsu, and N. Kawai (TokyoTech) report on behalf of the MITSuME collaboration: We observed the field of GRB 201223A (J.D. Gropp et al., GCN #29158, J. Wood et al., GCN #29161) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started at 2020-12-23 17:59:18 UT (52s after Swift BAT trigger). We detected the point source at the position consistent with the afterglow detected previously (Lipunov et al. GCN #29157, Gropp et al., GCN #29158, Z.P. Zhu et al. GCN #29159, Y.-D. Hu et al. GCN #29160). We measured the magnitudes as follows. T0+[sec] MID-UT T-EXP[sec] measured magnitudes ------------------------------------------------------------------------------------------------ 52 17:59:48 60 g'=15.45+/-0.05, Rc=15.04+/-0.03, Ic=14.77+/-0.04 ------------------------------------------------------------------------------------------------ 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., https://doi.org/10.1093/pasj/psaa091, https://arxiv.org/abs/2008.11486; https://github.com/MNiwano/Eclaire).
GCN 29165 table
GRB_name GRB201223A
GCN_number 29165
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 29165 SUBJECT: GRB 201223A: iTelescope optical afterglow observations DATE: 20/12/24 02:49:44 GMT FROM: Filipp Dmitrievich Romanov at Amateur astronomer I observed the field of GRB 201223A (Gropp et al., GCN Circ. 29158) with remote telescope T18 (0.32-m f/8.0 reflector + CCD) of iTelescope.Net in observatory AstroCamp at Nerpio (Spain) on 2020-12-23 since 19:49:22 UT (1 hour 50 minutes 56 seconds after the trigger). 5 images (with exposures 300, 120 and 180 seconds) were obtained with Astrodon luminance filter and 4 images (exposures: 300 and 60 seconds) with photometric Johnson V filter. I detected the optical afterglow in images with position: RA 08:51:09.46 Dec +71:10:47.00. It is not present in the Pan-STARRS images. The following magnitudes were measured from comparison to r magnitudes of nearby stars from Pan-STARRS DR1 catalogue (Chambers et al., 2016): Time of start (UT) Exp.time (s.) Bin. Mag. r Mag. error Filter --------------------------------------------------------------------------- 19:49:22 300 1 19.2 0.2 Luminance 19:56:25 300 1 19.3 0.4 V 20:26:25 300 2 19.9 0.4 V 20:33:07 300 2 20.1 0.3 Luminance --------------------------------------------------------------------------- Magnitudes were not corrected for Galactic extinction. Stacked image (4x300 + 2x120 + 180 sec.) available here: https://www.flickr.com/photos/filipp-romanov/50753199496
GCN 29166 table
GRB_name GRB201223A
GCN_number 29166
Detection_method Optical
ra 132.5894°
decl 71.2036°
Circular_text TITLE: GCN CIRCULAR NUMBER: 29166 SUBJECT: GRB 201223A: GWAC-F60A optical afterglow observations DATE: 20/12/24 06:56:16 GMT FROM: Liping Xin at NAOC, SVOM L. P. Xin(NAOC), L. H. Li(NAOC), X. H. Han(NAOC), J. Y. Wei(NAOC), J. Wang(GXU), C. Wu(NAOC), X. G. Wang(GXU), E. W. Liang (GXU), Y. L. Qiu(NAOC), and J. S. Deng(NAOC) report: We began to observe GRB 201223A (Gropp et al., GCN #29158, Wood et al., GCN #29161) with Xinglong GWAC-F60A telescope, China, at 17:59:10.1 (UT), 23th. Dec. 2020, about 44 sec after the burst. A series of R, I, and B band images were obtained. The optical afterglow reported by (Lipunov et al., GCN #29157; Gropp et al., GCN #29158; Zhu et al., GCN #29159; Hu et al.，GCN #29160; Hosokawa et al., GCN #29164; Filipp Dmitrievich Romanov GCN #29165) was clear detected in our images. The brightness is fading from 15.0 mag to 18.8 mag in R band during about 100 sec to 10000 sec after the burst. The R-band brightness is calibrated to the USNO B1.0 catalog, (RA=08:50:21.447, DEC=+71:12:12.80, J2000, R2=9.92) More analysis are still continuing. The message may be cited.
GCN 29167 table
GRB_name GRB201223A
GCN_number 29167
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 29167 SUBJECT: GRB 201223A: Mondy and Kitab optical observations DATE: 20/12/24 13:09:08 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI), A. Pozanenko (IKI), N. Pankov (HSE), E. Klunko (ISTP), A. Novichonok (Petrozavodsk State University, KIAM), Sh. Ehgamberdiev (UBAI) report on behalf of IKI-GRB-FuN: We observed the field of GRB 201223A (Gropp et al., GCN 29158) with AZT-33IK telescope of Sayan observatory (Mondy) starting on Dec. 23 (UT) 18:29:01 and Kitab-ISON RC-36 telescope starting (UT) 19:25:57. The optical transient (Lipunov et al. GCN 29157; Gropp et al., GCN 29158; Zhu et al. GCN 29159; Hu et al. GCN 29160; Hosokawa et al. GCN 29164; Romanov et al. GCN 29165; Xin et al. GCN 29166) is detected in our stacked images in R-filter. Preliminary photometry of the optical transient in a combined images is following Date UT start t-T0 Filter Exp. OT Err. UL(3sigma) (mid, days) (s) 2020-12-23 18:29:01 0.05943 R 10*120 18.95 0.23 19.5 AZT-33IK 2020-12-23 18:29:01 0.05943 R 55*120 19.38 0.09 22.1 AZT-33IK 2020-12-23 19:25:57 0.08161 R 60*60 19.40 0.20 19.6 RC-36 The photometry is based on the nearby USNO-B1.0 stars USNO-B1.0_id R2 1611-0080890 18.64 1612-0081305 18.44
GCN 29168 table
GRB_name GRB201223A
GCN_number 29168
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 29168 SUBJECT: GRB 201223A: GROWTH-India Telescope (GIT) photometric follow-up. DATE: 20/12/24 14:21:13 GMT FROM: Harsh Kumar at Indian Inst of Tech,Bombay H. Kumar (IITB), U. Stanzin (IAO), V. Bhalerao (IITB), G. C. Anupama (IIA), S. Barway (IIA), report on behalf of the GROWTH-India collaboration: We observed GRB 201223A detected by Swift-BAT (J.D. Gropp et al., GCN #29158); optical counterpart first reported by V. Lipunov et al., (GCN #29157) with 0.7m GROWTH-India Telescope, starting at 2020-12-23T18:30:33.51 UT. We obtained multiple images of 300 sec each in the r' filter. We clearly detected the afterglow at a position consistent with Swift-UVOT (GCN #29158) and MASTER-Net OT (GCN #29157) positions. We obtained the following photometric results: ------------------------------------------------------------------ JD (start) | T_start-T0 (hrs) | Filter | Mag (AB)| ------------------------------------------------------------------ 2459207.27122 | 0.5 | r' | 18.52 +/- 0.03 2459207.28623 | 0.9 | r' | 19.12 +/- 0.04 2459207.32568 | 1.8 | r' | 19.98 +/- 0.09 2459207.34029 | 2.2 | r' | 20.15 +/- 0.09 ------------------------------------------------------------------ Combining our photometric results with r band measurements of Z.P. Zhu et. al., (GCN #29159), we conclude that the source is fading with a power-law index of 1.04 +/- 0.01. The magnitudes are calibrated against PanSTARRs PS1 data release, (Flewelling et al., 2018) and not corrected for galactic extinction. Processing of more data is underway. The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree field of view, set up by the Indian Institute of Astrophysics and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).
GCN 29169 table
GRB_name GRB201223A
GCN_number 29169
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 29169 SUBJECT: GRB 201223A: NOT optical upper limit and NEXT powerlaw decay DATE: 20/12/24 14:29:07 GMT FROM: Dong Xu at NAOC/CAS D. Xu (NAOC), D. B. Malesani (DTU Space), P. Galindo (NOT), Z.P. Zhu (NAOC, HUST), D. A. Kann (HETH/IAA-CSIC), report on behalf of a larger collaboration: We observed the field of GRB 201223A (Gropp et al., GCN 29158) using the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. We obtained 2x120s Sloan r-band frames starting at 02:21:52 UT on 2020-12-24, i.e., 8.4 hr after the BAT trigger. The previously reported optical afterglow (Lipunov et al. GCN 29157; Gropp et al., GCN 29158; Zhu et al. GCN 29159; Hu et al. GCN 29160; Hosokawa et al. GCN 29164; Romanov et al. GCN 29165; Xin et al. GCN 29166; Belkin et al., GCN 29167; Kumar et al., GCN 29168) is not detected in the stacked image, down to a limiting magnitude of r > 22.0 mag. Further analysis of our previous NEXT observations (Zhu et al. GCN 29159) shows that the afterglow is decaying as F_rband ~ t^(-\alpha), where \alpha = 1.1 since the very beginning. The afterglow would be slightly fainter than 22.0 mag if this powerlaw decay is extrapolated until the NOT observational time, being consistent with the observed NOT upper limit. So the afterglow could be decaying in a single powerlaw until the NOT observation or have broken to a steeper decay before the NOT observation.
GCN 29170 table
GRB_name GRB201223A
GCN_number 29170
Detection_method Swift-XRT Det
ra 132.7902°
decl 71.1792°
Circular_text TITLE: GCN CIRCULAR NUMBER: 29170 SUBJECT: GRB 201223A: Enhanced Swift-XRT position DATE: 20/12/24 14:52:52 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 1078 s of XRT Photon Counting mode data and 2 UVOT images for GRB 201223A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 132.79017, +71.17923 which is equivalent to: RA (J2000): 08h 51m 9.64s Dec (J2000): +71d 10' 45.2" with an uncertainty of 1.8 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN 29171 table
GRB_name GRB201223A
GCN_number 29171
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 29171 SUBJECT: GRB 201223A: Swift-XRT refined Analysis DATE: 20/12/24 15:18:33 GMT FROM: Phil Evans at U of Leicester M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester) and J.D. Gropp report on behalf of the Swift-XRT team: We have analysed 8.0 ks of XRT data for GRB 201223A (Gropp et al. GCN Circ. 29158), from 81 s to 18.2 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 29170). The light curve can be modelled with a power-law decay with a decay index of alpha=0.82 (+/-0.04). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.87 (+0.18, -0.13). The best-fitting absorption column is 4.1 (+4.0, -0.9) x 10^20 cm^-2, consistent with the Galactic value of 3.1 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.5 x 10^-11 (2.8 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.1 (+4.0, -0.9) x 10^20 cm^-2 Galactic foreground: 3.1 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 1.87 (+0.18, -0.13) If the light curve continues to decay with a power-law decay index of 0.82, the count rate at T+24 hours will be 5.7 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.0 x 10^-13 (1.6 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/01014316. This circular is an official product of the Swift-XRT team.
GCN 29173 table
GRB_name GRB201223A
GCN_number 29173
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 29173 SUBJECT: GRB 201223A: 1.3m DFOT and 1.04m ST optical observations DATE: 20/12/24 17:09:51 GMT FROM: Rahul Gupta at ARIES, India Rahul Gupta (ARIES), Dimple (ARIES), Amit Kumar (ARIES), Vineet Ojha (ARIES), Ankur Ghosh (ARIES), Amar Aryan (ARIES), Shashi B. Pandey (ARIES), and Kuntal Misra (ARIES) report: We observed the optical afterglow ( Lipunov et al., GCN 29157; Gropp et al., GCN 29158; Zhu et al., GCN 29159; Hu et al., GCN 29160; Hosokawa et al., GCN 29164; Romanov et al., GCN 29165; Xin et al., GCN 29166; Belkin et al., GCN 29167; and Kumar et al., GCN 29168) of Swift and Fermi detected GRB 201223A (Gropp et al., GCN 29158; and Wood et al., GCN 29161) using the 1.3m Devasthal Fast Optical Telescope (DFOT) and 1.04m Sampurnanand Telescope (ST) of Aryabhatta Research Institute of Observational Sciences (ARIES), India. The observations were started on 2020-12-23 at 19:01:46 UT. Multiple frames having an exposure time of 300 s were taken in the I filter using DFOT and in BVRI filters using ST. We clearly detected the optical counterpart at the position reported by Gropp et al., GCN 29158. The preliminary photometric estimate of the afterglow using I band data of DFOT is the following : Date Start_UT T_start-T0 (hrs) Filter Exp time (s) Magnitude Mag_err ------------------------------ ------------------------------ ------------------------------ ------------------------------ 2020-12-23 19:07:55 1.158 I 300*1 18.71 0.04 ------------------------------ ------------------------------ ------------------------------ ------------------------------ The magnitude is 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. Further processing of data is going on. This circular may be cited.
GCN 29174 table
GRB_name GRB201223A
GCN_number 29174
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 29174 SUBJECT: GRB 201223A: AbAO optical observations DATE: 20/12/24 21:31:45 GMT FROM: Alexei Pozanenko at IKI, Moscow N. Pankov (HSE, IKI), A. Pozanenko (IKI), S. Belkin (IKI), R. Ya. Inasaridze (AbAO), V. R. Ayvazian (AbAO), G. V. Kapanadze (AbAO), A. Volnova (IKI) report on behalf of IKI-GRB-FuN: We observed the field of GRB 201223A (Gropp et al., GCN 29158; Wood et al., GCN 29161) with AS-32 telescope of Abastumani observatory (AbAO) in R-filter. The optical afterglow (Lipunov et al., GCN 29157; Gropp et al., GCN 29158; Zhu et al., GCN 29159; Hu et al., GCN 29160; Hosokawa et al., GCN 29164; Romanov et al., GCN 29165; Xin et al., GCN 29166; Belkin et al., GCN 29167; Kumar et al., GCN 29168; Xu et al., GCN 29169; Gupta et al., GCN 29173) is detected in stacked images. Date UT start t-T0 Filter Exp. OT Err. UL(3sigma) (mid, days) (s) 2020-12-23 19:39:59 0.0733 R 8*60 19.38 0.17 19.8 2020-12-23 21:19:22 0.1517 R 35*60 20.28 0.13 20.9 The photometry is based on nearby USNO-B1.0 stars.
GCN 29176 table
GRB_name GRB201223A
GCN_number 29176
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 29176 SUBJECT: GRB 201223A: HCT optical upper limit DATE: 20/12/26 05:51:35 GMT FROM: Harsh Kumar at Indian Inst of Tech,Bombay H. Kumar(IITB), D. K. Sahu (IIA), V. Bhalerao(IITB), G. C. Anupama(IIA), S. Barway(IIA) report on behalf of the HCT team: We observed GRB 201223A detected by Swift-BAT (J.D. Gropp et al., GCN #29158); optical counterpart first reported by V. Lipunov et al., (GCN #29157) with 2.0m Himalayan Chandra Telescope (HCT). We obtained a series of 180-sec exposures in the Bessell R filter and did not detect the afterglow in our stacked image. We obtained the following upper limit: ------------------------------------------------------------------- JD (mid) | T_mid-T0(hrs) | Exposure | Filter | Lim_mag (5-sigma) | ------------------------------------------------------------------- 2459208.4569 | 28.99 | 180*10 (stacked) | Bessell R | > 22.49 | ------------------------------------------------------------------- Our upper limit is consistent with power-law decay extrapolation suggested by D. Xu et al., (GCN #29169), Kumar et al., (GCN #29168). These observations were carried out under the ToO program "HCT-2020-C3-P6". We thank HCT staff for undertaking the observations.
GCN 29177 table
GRB_name GRB201223A
GCN_number 29177
Detection_method Swift-UVOT Det
ra 132.7896°
decl 71.1798°
Circular_text TITLE: GCN CIRCULAR NUMBER: 29177 SUBJECT: GRB 201223A: Swift/UVOT Detection DATE: 20/12/26 22:03:09 GMT FROM: Alexander Belles at PSU/Swift ​A. Belles (PSU) and J. D. Gropp (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 201223A 79 s after the BAT trigger (Gropp et al., GCN Circ. 29158). A source consistent with the XRT position (Goad et al., GCN Circ. 29170) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 08:51:09.51 = 132.78961 (deg.) Dec (J2000) = +71:10:47.4 = 71.17984 (deg.) with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence). Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 79 229 147 16.06+/-0.03 white 571 1019 186 18.04+/-0.08 white 5921 6121 196 >20.17 white 12121 12630 497 20.09+/-0.30 v 621 1069 58 >17.44 b 547 1167 58 17.97+/-0.25 b 11208 12115 885 >20.38 u_FC 292 541 246 16.75 +/- 0.04 u 694 1142 38 >17.58 w1 670 1118 58 >17.65 m2 645 1093 58 >17.87 w2 596 1045 58 >17.81 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).
GCN 29180 table
GRB_name GRB201223A
GCN_number 29180
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 29180 SUBJECT: GRB 201223A: AROMA-N Optical Observation DATE: 20/12/27 22:15:11 GMT FROM: Takanori Sakamoto at AGU M. Nakamura, K. Hasuda, T. Sakamoto (AGU) We observed the field of GRB 201223A detected by Swift (Gropp et al., GCN Circ. 29158) with the 14-inch AGU Robotic Optical Monitor for Astrophysical object - Narrow (AROMA-N) located at the Sagamihara campus of Aoyama Gakuin University. 58 images of 60 sec exposures were taken in the R filter starting from December 23 18:04:02 (UT) about 5.6 minutes after the trigger and stopped on December 23 19:16:09 (UT). We do not detect the optical afterglow both in the individual images and the stacked image. The estimated five sigma upper limit of the combined image (total exposure of 3480 sec) is ~17.3 mag using the USNO-B1 catalog.
GCN 29201 table
GRB_name GRB201223A
GCN_number 29201
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 29201 SUBJECT: GRB 201223A: SVOM-GWAC detected the optical counterpart during prompt emission phase DATE: 20/12/30 00:50:53 GMT FROM: Liping Xin at NAOC, SVOM L. P. Xin(NAOC), X. H. Han(NAOC), J. Y. Wei(NAOC), L. H. Li(NAOC), J. Wang(GXU), D. Turpin(CEA), H. B. Cai(NAOC), X. Y. Wang(NJU), C. Wu(NAOC), X. G. Wang(GXU), Z. G. Dai (NJU), G. W. Li(NAOC), E. W. Liang (GXU), S.S.Sun(GXU), L. Huang(NAOC), X. M. Lu(NAOC), Y. G. Yang(HNU), C. Gao(GXU), Y. L. Qiu(NAOC), and J. S. Deng(NAOC) report: The optical counterpart of GRB 201223A (Gropp et al., GCN #29158, Wood et al., GCN #29161) reported by (Lipunov et al., GCN #29157; Gropp et al., GCN #29158; Zhu et al., GCN #29159; Hu et al., GCN #29160; Hosokawa et al., GCN #29164; Filipp Dmitrievich Romanov GCN #29165; Xin et al., GCN #29166; Belkin et al., GCN #29167; Kumar et al., GCN #29168; Xu et al., GCN #29169; Gupta te al., GCN #29173; Pankov et al., GCN #29174; Kumar et al., GCN #29176; Belles et al., GCN #29177 ) was detected by Ground Wide Angle Camera (GWAC) in white band at Xinglong observatory, China, during the Swift prompt emission phase. The exposure time for each GWAC image is 10 seconds. Preliminary process showed that the brightness was about R~15.5 mag at ~2 sec after the burst, and then brighten to the peak of R~14.8 mag at about 80 sec post the trigger time. All these magnitudes were calibrated to USNO B1.0 R2 mag catalog. More analyses are still continuing.