March 2025 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 37838] GRB 250321A: Swift-BAT refined analysis
by GCN Circulars 21 Mar '25

21 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39821 SUBJECT: GRB 250321A: Swift-BAT refined analysis DATE: 25/03/21 18:34:55 GMT FROM: Rahul Gupta at NASA GSFC <rahul.gupta(a)nasa.gov> R. Gupta (GSFC), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 250321A (trigger #1297508) (Gupta, et al., GCN Circ. 39794). The BAT ground-calculated position is RA, Dec = 295.100, 21.055 deg which is RA(J2000) = 19h 40m 23.9s Dec(J2000) = +21d 03' 16.4" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 24%. The mask-weighted BAT light curve shows a sharp peak at the trigger time, followed by a rapid decline. T90 (15-350 keV) is 6.21 +- 1.36 sec (estimated error including systematics). The time-averaged spectrum from T-0.14 to T+7.35 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.61 +- 0.19. The fluence in the 15-150 keV band is 6.7 +- 0.8 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T-0.16 sec in the 15-150 keV band is 3.2 +- 0.5 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1297508 View this GCN Circular online at https://gcn.nasa.gov/circulars/39821. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37837] GRB 250321A: Swift-XRT refined Analysis
by GCN Circulars 21 Mar '25

21 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39820 SUBJECT: GRB 250321A: Swift-XRT refined Analysis DATE: 25/03/21 18:23:30 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), M. A. Williams (PSU), S. Dichiara (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: We have analysed 6.8 ks of XRT data for the Swift-BAT-detected burst GRB 250321A, from 108 s to 39.4 ks after the Swift-BAT trigger. The data comprise 9 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. Using 1662 s of PC mode data and 3 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 295.09844, +21.04038 which is equivalent to: RA (J2000): 19h 40m 23.62s Dec(J2000): +21d 02' 25.4" with an uncertainty of 2.6 arcsec (radius, 90% confidence). This position is 72 arcsec from the Swift-BAT position. The light curve can be modelled with a power-law decay with a decay index of alpha=1.13 (+0.11, -0.10). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.2 (+1.3, -1.0). The best-fitting absorption column is 3.7 (+3.4, -2.2) x 10^22 cm^-2, in excess of the Galactic value of 1.1 x 10^22 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 7.3 x 10^-11 (2.4 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 3.7 (+3.4, -2.2) x 10^22 cm^-2 Galactic foreground: 1.1 x 10^22 cm^-2 Excess significance: 2.0 sigma Photon index: 2.2 (+1.3, -1.0) If the light curve continues to decay with a power-law decay index of 1.13, the count rate at T+24 hours will be 6.9 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.0 x 10^-14 (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/01297508. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/39820. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37836] GRB 250320B: Fermi-LAT detection
by GCN Circulars 21 Mar '25

21 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39819 SUBJECT: GRB 250320B: Fermi-LAT detection DATE: 25/03/21 18:05:59 GMT FROM: A. Holzmann Airasca at University of Trento and INFN Bari <a.holzmannairasca(a)unitn.it> A. Holzmann Airasca (UniTrento and INFN Bari), S. Lopez (CNRS / IN2P3), P. Monti-Guarnieri (University and INFN, Trieste), N. Di Lalla (Stanford Univ.), F. Longo (University and INFN, Trieste) and R. Gupta (NASA GSFC) report on behalf of the Fermi-LAT Collaboration: On March 20, 2025, Fermi-LAT detected high-energy emission from GRB 250320B, which was also detected by Fermi-GBM (trigger 764205327 / 250320969, GCN 39792), AstroSat CZTI (GCN 39808) and SVOM/GRM (GCN 39813). The best LAT on-ground location is found to be: RA, Dec = 244.66, -30.37 (J2000) with an error radius of 0.3 deg (90 % containment, statistical error only). This was 40 deg from the LAT boresight at the time of the GBM trigger (T0 = 23:15:22.02 UT). The data from the Fermi-LAT shows a significant increase in the event rate that is spatially and temporally correlated with the GBM emission with high significance. The photon flux above 100 MeV in the time interval 0 - 1400 s after the GBM trigger is (3.6 ± 1.1) E-6 ph/cm2/s. The estimated photon index above 100 MeV is -2.35 ± 0.31. The highest-energy photon is a 1.9 GeV event which is observed ~ 245 seconds after the GBM trigger. A Swift ToO has been requested for this burst. The Fermi-LAT point of contact for this burst is Aldana Holzmann Airasca (aldana.holzmannairasca(a)ba.infn.it). The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. View this GCN Circular online at https://gcn.nasa.gov/circulars/39819. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37835] GRB 250321B: SVOM detection of a sub-threshold transient event
by GCN Circulars 21 Mar '25

21 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39818 SUBJECT: GRB 250321B: SVOM detection of a sub-threshold transient event DATE: 25/03/21 16:40:37 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> S. Schanne (CEA), M. Brunet (IRAP), D. Turpin (CEA), T. Maiolino, F. Piron (LUPM), O. Godet, J-L. Atteia (IRAP) report on behalf of the SVOM mission team The SVOM/ECLAIRs telescope detected a transient source appearing below the onboard trigger thresholds, labelled GRB 250321B starting at 2025-03-21T03:36:28 UTC (Tb). The information of this sub-threshold source was received on the ground with low-latency by the SVOM VHF Alert Network. After arrival of the X-band data the source detection is confirmed. The burst was detected below the thresholds applied onboard by both the Count-Rate Trigger (CRT) and Image Trigger (IMT). It has been reported in the log messages of the onboard trigger downloaded via X-band. The best detection is found by IMT with a signal-to-noise ratio of 6.45 in the 8-120 keV energy band over a time window of 20.48 s starting at Tb. After reprocessing the photon by photon data in the onboard trigger replay with lower thresholds, as well as the on-ground offline trigger, a point-like source is confirmed in the reconstructed sky images. The localization of the source is RA, Dec = 169.687, 39.560 (J2000). The uncertainty on this position is about 12 arcminutes at 90% C.L. We notice the presence of several quasars in this error box, among which the closest is SDSS J111850.26+393258.6 located at 1.2 arcmin. We encourage follow-up observation of this source candidate. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. The point of contact for this event is Stéphane Schanne (s.schanne AT cea.fr) by email if you require additional information. View this GCN Circular online at https://gcn.nasa.gov/circulars/39818. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37834] EP250321a: SVOM/VT optical observation
by GCN Circulars 21 Mar '25

21 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39817 SUBJECT: EP250321a: SVOM/VT optical observation DATE: 25/03/21 15:58:18 GMT FROM: Xuhui Han at NAOC/SVOM <hxh(a)nao.cas.cn> X. H. Han, Z. H. Yao, L. P. Xin, Y. L. Qiu, H. L. Li, Y. Xu, P. P. Zhang, W. J. Xie, J. Wang, Y. J. Xiao, H. B. Cai, J. Y. Wei (NAOC) report on behalf of the SVOM mission team. SVOM/VT conducted ToO follow-up observations of the X-ray transient EP250321a (Hu et al., GCN 39800) at the location of WXT position in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channel simultaneously. The optical counterpart of EP250321a (Trigger ID: 01709133009, Fu et al., GCN 39804; Perez-Garcia et al., GCN 39805; Brivio et al., GCN 39807; Zhu et al., GCN 39809; Becerra et al., GCN 39810; Pérez-Fournon et al., GCN 39812; Lee et al., GCN 39815) was clearly detected in VT_R and VT_B images. The brightness in AB magnitude was estimated to be: Mid time UTC | Band | Exposure Time (second) | Magnitude | Magnitude error 2025-03-21T10:29:29 | VT_B | 2940 | 21.85 | 0.09 2025-03-21T10:29:29 | VT_R | 2940 | 19.39 | 0.03 The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC),CAS. View this GCN Circular online at https://gcn.nasa.gov/circulars/39817. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37833] EP 250321A: Optical counterpart detection by LCO.
by GCN Circulars 21 Mar '25

21 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39816 SUBJECT: EP 250321A: Optical counterpart detection by LCO. DATE: 25/03/21 15:19:10 GMT FROM: ankur ghosh at CAPP, University of Johannesburg <ghosh.ankur1994(a)gmail.com> Ankur Ghosh, Soebur Razzaque (CAPP, University of Johannesburg), Rahul Gupta (NASA GSFC), Alexander Moskvitin, Yulia Sotnikova (SAO RAS), Naveen Dukiya (ARIES) on behalf of a larger collaboration. We observed the field of the GRB 250321A triggered by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission (Hu et al., GCN 39800) in the r, V filter of the 1-meter Sinistro telescope at the Las Cumbres Observatory Global Telescope (LCOGT) node located at Siding Spring is near Coonabarabran, New South Wales, Australia . The 1-m Sinistro telescope is equipped with a 4K x 4K CCD (FOV: 26 x 26 arcmin, scale: 0.39 arcsec/pixel). Observations began on March 21, 2025, starting 5.46 hours after the GRB trigger. We clearly detect the optical transient (OT) reported by GCNs (Fu et al. GCN 39804, Perez-Garcia et al al., GCN 39805; Brivio et al., GCN 39807; Zhu et al., GCN 39809; Becerra et al., GCN 39810; Pérez-Fournon et al., GCN 39812, Lee et al., GCN 39815) in our r, V band image. |Date| |UTstart| |t-T0 (hours)| |Exp (sec)| |Filter| |Magnitude| ---------------------------------------------------------------------------------------------- 2025-03-21 11:38:04.13 5.468 1 x 900 r r = 21.40 +/- 0.07 2025-03-21 11:38:20.54 5.472 1 x 900 V V = 21.76 +/- 0.09 The field was calibrated against nearby APASS stars, with magnitudes converted using Lupton (2005) equations, and has not been corrected for Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/39816. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37832] EP250321a: Kinder optical follow-up observations
by GCN Circulars 21 Mar '25

21 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39815 SUBJECT: EP250321a: Kinder optical follow-up observations DATE: 25/03/21 14:45:24 GMT FROM: Janet Chen at National Central University <janetstars(a)gmail.com> Y.-H. Lee, A. Aryan, T.-W. Chen, Y. J. Yang, W.-J. Hou, H.-Y. Hsiao (all NCU), A. K. H. Kong (NTHU), J. Gillanders (Oxford), S. J. Smartt (Oxford/QUB), M.-H. Lee, Y.-C. Pan, C.-C. Ngeow, A. Sankar. K, C.-H. Lai, C.-S. Lin, H.-C. Lin, J.-K. Guo (all NCU), S. Yang, L. L. Fan, Z. N. Wang, G. H. Sun (all HNAS), H.-W. Lin (UMich), H. F. Stevance, S. Srivastav, L. Rhodes (all Oxford), M. Nicholl, M. Fulton, T. Moore, K. W. Smith, C. Angus, A. Aamer (all QUB), A. Schultz and M. Huber (both IfA, Hawaii) report: We observed the field of the fast X-ray transient EP250321a (Hu et al., GCN 39800) using the 1m LOT (in g and r band) and 40cm SLT (in i and z band) at Lulin Observatory in Taiwan as part of the Kinder collaboration (Chen & Yang et al. 2024, arXiv:2406.09270). The first LOT epoch of observations in the r band started at 11:57 UT on the 21st of March 2025 (MJD 60755.498), ~5.78 hrs after the EP trigger, while the first SLT epoch of observations in the i band started at 12:23 UT on the 21st of March 2025 (MJD 60755.516), ~6.21 hrs after the EP trigger. We utilized the astroalign (Beroiz et al., 2020, A&C, 32, 100384) and astropy (Astropy Collaboration et al., 2022, ApJ, 935, 167) packages to align and stack the individual frames. In the stacked images, we clearly detected the optical counterpart candidate proposed by Fu et al. (GCN 39804) and confirmed by several other observations (e.g., Perez-Garcia et al al., GCN 39805; Brivio et al., GCN 39807; Zhu et al., GCN 39809; Becerra et al., GCN 39810; Pérez-Fournon et al., GCN 39812). We employed the Python-based package AutoPhOT (Brennan & Fraser, 2022, A&A, 667, A62) to perform PSF photometry on individual frames. The details of the observation and measured photometry from the first frame (in the AB system) were as follows: Telescope | Filter | MJD (start) | t-t0 (hr) | Exposure (s) | Magnitude | Seeing | Airmass LOT | r | 60755.498 | 5.78 | 300 * 6 | 21.86 +/- 0.07 | 1".1 | 1.63 SLT | i | 60755.516 | 6.21 | 300 * 12 | 20.75 +/- 0.10 | 1".4 | 1.36 LOT | g | 60755.520 | 6.31 | 300 * 6 | >22.04 | 1".5 | 1.41 The presented magnitudes were calibrated using the field stars from the Pan-STARRS1 catalog and were not corrected for the expected Galactic foreground extinction corresponding to a reddening of A_r = 0.12 mag, A_i = 0.09 mag, and A_g = 0.17 mag, respectively, in the direction of the transient (Schlafly & Finkbeiner 2011). View this GCN Circular online at https://gcn.nasa.gov/circulars/39815. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37831] GRB 250321A: Swift/UVOT Upper Limits
by GCN Circulars 21 Mar '25

21 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39814 SUBJECT: GRB 250321A: Swift/UVOT Upper Limits DATE: 25/03/21 13:55:16 GMT FROM: Sam Shilling at Lancaster University <shilling.sam(a)gmail.com> S. P. R. Shilling (Lancaster U.) and R. Gupta (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 250321A 128 s after the BAT trigger (Gupta et al., GCN Circ. 39794). No optical afterglow consistent with the XRT position (Page et al., GCN Circ. 39798) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 128 278 147 >19.9 white 128 4071 344 >20.6 v 4282 4482 197 >18.9 b 3667 5142 236 >20.0 u 340 5097 232 >19.4 w1 4693 4892 197 >19.3 m2 4487 4687 197 >19.2 w2 4077 4277 197 >19.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 4.368 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/39814. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37830] GRB 250320B: SVOM/GRM observation of a long burst
by GCN Circulars 21 Mar '25

21 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39813 SUBJECT: GRB 250320B: SVOM/GRM observation of a long burst DATE: 25/03/21 13:20:50 GMT FROM: wenlongzhang2018(a)163.com SVOM/GRM team: Wen-Long Zhang, Wen-Jun Tan, Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Nicolas Dagoneau (CEA), Maria-Grazia Bernardini (INAF-OAB), Jean-Luc Atteia (IRAP), Frédéric Piron (LUPM) Report on behalf of the SVOM team: SVOM/GRM was triggered in-flight by GRB 250320B (SVOM trigger reference: sb25032001) at 2025-03-20T23:15:23.000 (T0), which was also observed by Fermi/GBM (Fermi GBM team, GCN #39792) and AstroSat CZTI (J. Joshi et al., GCN 39808). With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multi-peaks with a T90 of 86.5 +0.5/-1.0 s in the 15-5000 keV band. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb250320B.png In addition, the position of this burst, as determined by Fermi/GBM (Fermi GBM Team, GCN #39792), is located at about 53.9 degrees (with a few degrees of statistical and systematic errors) from the SVOM optical axis. This burst was detected by the Count-Rate Trigger onboard ECLAIRs, as an increase in counts over background, but it was not localized by the coded-mask imaging process, which confirms that the burst occurred outside the ECLAIRs field of view. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM/GRM point of contact for this burst is: Wen-Long Zhang (IHEP) (zhangwl(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/39813. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37829] EP250321a: LCO optical counterpart detection
by GCN Circulars 21 Mar '25

21 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39812 SUBJECT: EP250321a: LCO optical counterpart detection DATE: 25/03/21 12:58:42 GMT FROM: Ismael Perez-Fournon at Instituto de Astrofisica de Canarias <ipf(a)iac.es> I. Pérez-Fournon, F. Poidevin (IAC and ULL), D. Cano-Morales, I. Correa-Plasencia, A.E. Hernández-Díaz (ULL), D. Aguado, A. López-Oramas, D. Nespral (IAC and ULL), N.C. Sun (UCAS), W. Li, Y. Wang, and Z. Niu (NAOC) We report Las Cumbres Observatory Global Telescope network (LCOGT) observations of EP250321a detected by EP/WXT (Hu et al., GCN circ. 39800), and Swift-XRT (Page et al., GCN circ. 39811). We observed the field of EP250321a with one of the two LCOGT 1-m telescopes, equipped with Sinistro cameras, located at the LCOGT node at McDonald Observatory (Texas). We obtained a 200-sec exposure in the SDSS i' filter starting at 2025-03-21 09:38:42 UT, about 3.48 hr after the EP trigger. An uncatalogued source is detected at the position of the optical and near-IR counterpart reported by Fu et al. (GCN circ. 39804), Perez-Garcia et al. (GCN circ. 39805), Brivio et al. (GCN circ. 39807), Zhu et al. (GCN circ. 39809), and Becerra et al. (GCN circ. 39810). Zhu et al. (GCN circ. 39809) have reported a redshift of z = 4.368. We measure the following magnitude, calibrated against Pan-STARRS DR2 stars and not corrected for Galactic extinction: Date | UT start | mag | error | filter | ---------------------------------------------- 2025-03-21 09:38:42 19.3 0.15 i' This work makes use of observations from the Las Cumbres Observatory global telescope network (LCOGT observing programme IAC2025A-009, SGLF). View this GCN Circular online at https://gcn.nasa.gov/circulars/39812. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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