GRB210912A

This page lists all entries on GRB210912A in GRBweb

Summary IPN Swift GCN 30820 GCN 30823 GCN 30824 GCN 30825 GCN 30829 GCN 30830 GCN 30832 GCN 30833 GCN 30834 GCN 30837 GCN 30839 GCN 30844 GCN 30861

Summary table
Variable Value Source
T0 11:01:11 UTC GCN_circulars,Swift Det
ra 129.8928° Swift
decl 79.2214° Swift
pos_error 6.08e-05° Swift
T90 28.35 s Swift
T90_start 11:01:11 UTC Swift
fluence 1.10e-06 erg/cm² Swift
T100 28.35 s
GBM_located False
mjd 59469.45915509259 GCN_circulars,Swift Det
IPN table
GRB_name GRB210912A
ra 129.7667°
decl 79.2000°
pos_error 5.00e-02°
Swift table
GRB_name GRB210912A
t_trigger 11:01:11 UTC
ra 129.8928°
decl 79.2214°
pos_error 6.08e-05°
T90 28.35 s
fluence 1.10e-06 erg/cm²
GCN 30820 table
GRB_name GRB210912A
GCN_number 30820
Detection_method Swift Det
t_trigger 11:01:11 UTC
ra 129.7690°
decl 79.1940°
Circular_text TITLE: GCN CIRCULAR NUMBER: 30820 SUBJECT: GRB 210912A: Swift detection of a burst DATE: 21/09/12 11:18:18 GMT FROM: David Palmer at LANL E. Troja (NASA/GSFC/UMCP), A. P. Beardmore (U Leicester), R. Caputo (NASA/GSFC), N. J. Klingler (GSFC/UMBC/CRESSTII), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift Observatory Team: At 11:01:11 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 210912A (trigger=1072990). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 129.769, +79.194 which is RA(J2000) = 08h 39m 04s Dec(J2000) = +79d 11' 38" 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 40 sec. The peak count rate was ~2800 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 11:02:04.1 UT, 52.6 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 129.88358, 79.22292 which is equivalent to: RA(J2000) = 08h 39m 32.06s Dec(J2000) = +79d 13' 22.5" with an uncertainty of 7.5 arcseconds (radius, 90% containment). This location is 129 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 2.40 x 10^20 cm^-2 (Willingale et al. 2013). The initial flux in the 2.5 s image was 6.40e-10 erg cm^-2 s^-1 (0.2-10 keV). There are no UVOT data available. Burst Advocate for this burst is E. Troja (eleonora.troja AT nasa.gov). 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 30823 table
GRB_name GRB210912A
GCN_number 30823
Detection_method Optical
ra 129.8929°
decl 79.2215°
Circular_text TITLE: GCN CIRCULAR NUMBER: 30823 SUBJECT: GRB 210912A: BOOTES-5/JGT optical afterglow candidate DATE: 21/09/12 15:04:10 GMT FROM: Youdong HU at IAA-CSIC Y.-D. Hu, T.-R. Sun, E. Fernandez-Garcia, A. J. Castro-Tirado, R. Sanchez-Ramirez and M.D. Caballero-Garcia (IAA-CSIC), D. Hiriart and W. H. Lee (UNAM), C. J. Perez del Pulgar and I. Carrasco (UMA), I. H. Park (SKKU) on behalf of a larger collaboration, report: The 60cm BOOTES-5/JGT robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) automatically responded in 13 s to the Swift trigger for GRB 210912A (Troja et al., GCNC 30820). In the co-added clear image (30 x 1 s), we find an uncataloged optical source at (J2000) coordinates RA: 8:39:34.30, DEC:+79:13:17.5, which is located at the edge of the XRT error box (Troja et al., GCNC 30820) and for which we measure R = 18.5 mag. We propose this source to be the GRB 210219A optical afterglow, pending confirmation of its variability. Further observations are ongoing. We thak the staff at San Pedro Martir for their support.
GCN 30824 table
GRB_name GRB210912A
GCN_number 30824
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 30824 SUBJECT: Swift GRB 210912A: Global MASTER-Net observations report DATE: 21/09/12 16:40:30 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-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 Swift GRB 210912A ( E. Troja et al., GCN 30820) errorbox 19826 sec after notice time and 19878 sec after trigger time at 2021-09-12 16:32:29 UT, with upper limit up to 15.0 mag. Observations started at twilight. The observations began at zenith distance = 57 deg. The sun altitude is -12.6 deg. The galactic latitude b = 32 deg., longitude l = 134 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1718486 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 5800 | MASTER- | C | 25 | 13.0 | 8423 | MASTER- | C | 20 | 17.6 | 8423 | MASTER- | C | 20 | 13.9 | 19968 | MASTER-Kislovodsk | C | 180 | 15.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 30825 table
GRB_name GRB210912A
GCN_number 30825
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 30825 SUBJECT: GRB 210912A: Mondy optical afterglow confirmation DATE: 21/09/12 17:21:48 GMT FROM: Alexei Pozanenko at IKI, Moscow N. Pankov (HSE), S. Belkin (IKI), A. Pozanenko (IKI), E. Klunko (ISTP) report on behalf of GRB IKI FuN: We observed the field of GRB 210912A (Troja et al., GCN 30820) with AZT-33IK telescope of Sayan observatory (Mondy) starting on 2021-09-12(UT) 12:57:48. We obtained 30 images in R-filter. We confirm the fading object suggested by Hu et al. (GCN 30823) as the optic afterglow of GRB 210912A. Preliminary photometry of the object in stacked images is following Date UT start t-T0 Filter Exp. OT Err. UL(3sigma) (mid, days) (s) 2021-09-12 12:57:48 0.10112 R 29*120 21.33 0.14 22.5 The photometry is based on the nearby USNO-B1.0 stars RA DEC R2 08:39:12.26208 +79:12:37.1304 15.88 08:39:10.94880 +79:16:33.8916 15.26
GCN 30829 table
GRB_name GRB210912A
GCN_number 30829
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 30829 SUBJECT: GRB 210912A: Host-galaxy candidate in PanSTARRS DATE: 21/09/12 18:48:08 GMT FROM: Alexander Kann at IAA-CSIC D. A. Kann (HETH/IAA-CSIC) reports: At the afterglow position (Hu et al., GCN #30823, see also Pankov et al., GCN #30825) of the Swift GRB 210912A (Troja et al., GCN #30820), an object is visible in Pan-STARRS pre-imaging at position (J2000): RA = 129.89171813 Dec. = +79.22157927 in agreement with the position given by Hu et al., GCN #30823, with magnitudes: g' = 23.19 +/- 0.23 mag, r' = 23.09 +/- 0.36 mag, i' = 22.48 +/- 0.13 mag, z' = 22.43 +/- 0.25 mag. It is undetected in Y. We suggest this object to be the host galaxy of GRB 210912A. This may be indicative that this is a low-redshift event which may be followed by a detectable supernova. Further follow-up despite the very northerly position is warranted.
GCN 30830 table
GRB_name GRB210912A
GCN_number 30830
Detection_method Swift-XRT Det
ra 129.8899°
decl 79.2215°
Circular_text TITLE: GCN CIRCULAR NUMBER: 30830 SUBJECT: GRB 210912A: Enhanced Swift-XRT position DATE: 21/09/12 20:48:34 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 526 s of XRT Photon Counting mode data and 1 UVOT images for GRB 210912A, 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 = 129.88990, +79.22148 which is equivalent to: RA (J2000): 08h 39m 33.58s Dec (J2000): +79d 13' 17.3" with an uncertainty of 2.6 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 30832 table
GRB_name GRB210912A
GCN_number 30832
Detection_method Swift-UVOT Det
ra 129.8928°
decl 79.2214°
Circular_text TITLE: GCN CIRCULAR NUMBER: 30832 SUBJECT: GRB 210912A: Swift/UVOT Detection DATE: 21/09/13 07:47:54 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 210912A 60 s after the BAT trigger (Troja et al., GCN Circ. 30820). A source consistent with the optical position (Hu et al. GCN Circ. 30823) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 08:39:34.27 = 129.89280 (deg.) Dec (J2000) = +79:13:17.1 = 79.22141 (deg.) with an estimated uncertainty of 0.47 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 60 209 147 18.73 +/- 0.08 v 602 621 19 >17.8 b 528 547 19 >18.3 u 272 490 214 19.56 +/- 0.31 w2 577 597 19 >18.8 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.027 in the direction of the burst (Schlegel et al. 1998).
GCN 30833 table
GRB_name GRB210912A
GCN_number 30833
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 30833 SUBJECT: GRB 210912A: Swift-XRT refined Analysis DATE: 21/09/13 09:18:53 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), D.N. Burrows (PSU), J. D. Gropp (PSU), J.A. Kennea (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester) and E. Troja report on behalf of the Swift-XRT team: We have analysed 4.1 ks of XRT data for GRB 210912A (Troja et al. GCN Circ. 30820), from 46 s to 29.0 ks after the BAT trigger. The data comprise 32 s in Windowed Timing (WT) mode (the first 5 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 30830). The light curve can be modelled with an initial power-law decay with an index of alpha=3.4 (+/-0.4), followed by a break at T+140 s to an alpha of 0.68 (+/-0.05). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.67 (+0.25, -0.23). The best-fitting absorption column is 1.2 (+0.9, -0.7) x 10^21 cm^-2, in excess of the Galactic value of 2.4 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 4.1 x 10^-11 (4.7 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.2 (+0.9, -0.7) x 10^21 cm^-2 Galactic foreground: 2.4 x 10^20 cm^-2 Excess significance: 2.2 sigma Photon index: 1.67 (+0.25, -0.23) If the light curve continues to decay with a power-law decay index of 0.68, the count rate at T+24 hours will be 0.014 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.7 x 10^-13 (6.6 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/01072990. This circular is an official product of the Swift-XRT team.
GCN 30834 table
GRB_name GRB210912A
GCN_number 30834
Detection_method Swift Det
t_trigger 20:04:34 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 30834 SUBJECT: GRB 210912A: CAHA 2.2m Detection DATE: 21/09/13 09:35:41 GMT FROM: Alexander Kann at IAA-CSIC D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), C. Thoene, M. Blazek, J. F. Agui Fernandez (all HETH/IAA-CSIC), and S. Gongora (CAHA) report: We observed GRB 210912A (Swift detection: Troja et al., GCN #30820) with CAFOS mounted on the 2.2m CAHA telescope at Calar Alto, Almeria, Spain. We obtained 7 x 60 s in the SDSS i' band under passing clouds, starting at 20:04:34 UT (9.056 hrs after the trigger; further observations at a later time were prevented by cloud cover). The afterglow (Hu et al., GCN #30823; Pankov et al., GCN #30825; Kuin & Troja, GCN #30832) is faintly detected in the stacked image. Compared to a nearby Pan-STARRS comparison star, we measure (AB mag) i' = 21.66 +/- 0.15 mag at 0.38146 d after the GRB, further confirming the decaying afterglow. This is still significantly brighter than the potential underlying host galaxy (Kann, GCN #30829).
GCN 30837 table
GRB_name GRB210912A
GCN_number 30837
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 30837 SUBJECT: GRB 210912A: Tautenburg observations DATE: 21/09/13 16:25:04 GMT FROM: Ana Nicuesa at TLS Tautenburg A. Nicuesa Guelbenzu, S. Klose, S. Melnikov, B. Stecklum, C. Hoegner (all TLS Tautenburg) report: We observed the field of GRB 210912A (Troja et al., GCN 30820) with the Tautenburg 1.34m Schmidt telescope equipped with the TAUKAM 6kx6k CCD camera and the Sloan r-band filter. Observations were performed on September 12, at a midtime of 19.33 UT, 22.17 UT, and 02:36 UT (Sep 13). The optical transient (Hu et al., GCN 30823; Pankov et al., GCN 30825; Kuin & Troja, GCN 30832; Kann et al. GCN 30833) is detected with the following preliminary AB magnitudes: r_1 = 21.95 +- 0.19, r_2 = 22.17 +- 0.19, r_3 = 22.53 +- 0.19. Magnitudes are calibrated against the Pan-STARRS catalogue. A comparison with the previous observations suggests that around 0.6 days the decay index of the light curve has increased from a rather modest value of alpha = 0.4 to alpha about 1. Further observations are required in order to provide a more precise decay index.
GCN 30839 table
GRB_name GRB210912A
GCN_number 30839
Detection_method Swift-BAT Det
ra 129.8740°
decl 79.2160°
Circular_text TITLE: GCN CIRCULAR NUMBER: 30839 SUBJECT: GRB 210912A: Swift-BAT refined analysis DATE: 21/09/13 23:34:08 GMT FROM: Sibasish Laha at GSFC M. Stamatikos (OSU), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), 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 210912A (trigger #1072990) (Troja et al., GCN Circ. 30820). The BAT ground-calculated position is RA, Dec = 129.874, 79.216 deg which is RA(J2000) = 08h 39m 29.7s Dec(J2000) = +79d 12' 59.3" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The BAT light curve showed a complex structure with a duration of about ~30 sec. T90 (15-350 keV) is 28.35 +- 14.34 sec (estimated error including systematics). The time-averaged spectrum from T-23 to T+25 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.61 +- 0.13. The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+0.23 sec in the 15-150 keV band is 1.7 +- 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/1072990/BA/
GCN 30844 table
GRB_name GRB210912A
GCN_number 30844
Detection_method Optical
ra 129.8929°
decl 79.2215°
Circular_text TITLE: GCN CIRCULAR NUMBER: 30844 SUBJECT: GRB 210912A: BOOTES-5/JGT optical afterglow candidate (Correction to GCNC 30823) DATE: 21/09/17 11:55:37 GMT FROM: Youdong HU at IAA-CSIC Y.-D. Hu, T.-R. Sun, E. Fernandez-Garcia, A. J. Castro-Tirado, R. Sanchez-Ramirez and M.D. Caballero-Garcia (IAA-CSIC), D. Hiriart and W. H. Lee (UNAM), C. J. Perez del Pulgar and I. Carrasco (UMA), I. H. Park (SKKU) on behalf of a larger collaboration, report: The 60cm BOOTES-5/JGT robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) automatically responded in 13 s to the Swift trigger for GRB 210912A (Troja et al., GCNC 30820). In the co-added clear image (30 x 1 s), we find an uncataloged optical source at (J2000) coordinates RA: 8:39:34.30, DEC:+79:13:17.5, which is located at the edge of the XRT error box (Troja et al., GCNC 30820) and for which we measure R = 18.5 mag. We propose this source to be the GRB 210912A optical afterglow, pending confirmation of its variability. Further observations are ongoing. We thank the staff at San Pedro Martir for their support. In the GCNC 30823, we have a typo of the GRB name in the text and it was corrected now. We apologize for the possible confusion and inconvenience.
GCN 30861 table
GRB_name GRB210912A
GCN_number 30861
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 30861 SUBJECT: GRB 210912A: LBT optical observations DATE: 21/09/22 11:41:40 GMT FROM: Andrea Melandri at INAF-OAB A. Rossi (INAF-OAS Bologna) report on behalf of the CIBO collaboration: We observed the field of GRB 210912A (Troja et al., GCN 30820) in the r' band with the LBC imager mounted on LBT (Mt Graham, AZ, USA). We obtained 10min of imaging at the midtime 11:20 UT on 2021-09-17 (~5 days after the burst trigger). We clearly detect the optical afterglow (Hu et al., GCN 30823; Pankov et al., GCN 30825; Kuin & Troja, GCN 30832; Kann et al. GCN 30834; Nicuesa Guelbenzu et al. GCN 30837) with the following preliminary AB magnitude: r = 22.73 +- 0.05 calibrated against Pan-STARRS field stars. It is likely that this flux is significantly affected by host galaxy contamination (Kann et al. GCN 30829). We acknowledge the excellent support from the LBTO and LBT-INAF staff, particularly A. Cardwell, J. Williams and D. Paris, in obtaining these observations.