Catalog updates

Updates that changed GRBs that were already in the catalog

GRBweb is updated every day: new GRBs are added, and the information on recent GRBs is completed as it becomes available. Sometimes an update also changes GRBs that were already in the catalog, e.g. when a new source of information is added or an error is corrected. These updates are listed below, with what was changed and how this affected the list of GRBs. To repeat an analysis with the catalog as it was before an update, use the archived summary tables.

2026-10-29

GRBs detected by SVOM and Einstein Probe

Trigger times and positions are now also taken from the GCN circulars of SVOM and Einstein Probe, and 651 circulars that had been missed since 2023 were added. The catalog grew from 9,218 to 9,345 GRBs and the positions of 838 GRBs were refined.

What changed

  • GRBs triggered by SVOM (ECLAIRs or GRM) or Einstein Probe (WXT) are often not observed by Swift or Fermi-GBM. Their trigger time, position and position error are now read from the GCN circulars of these missions. Before, such GRBs were only included if another instrument provided a trigger time, or if they were listed in the Swift GRB table, which no longer lists GRBs that were not triggered by Swift.
  • 651 GCN circulars from June 2023 onwards had not been downloaded, due to an error in the script that downloads new circulars. These circulars were added.
  • Positions reported in Swift-XRT and Swift-UVOT circulars now come with their error, so that they can be compared with the positions of other instruments.
  • Values outside their valid range are no longer stored, e.g. positions with a typo in the source table, and position errors of 0 that actually mean that the error is unknown.
  • Corrections of GRB names published in later GCN circulars (errata) are now taken into account.

Effect on the list of GRBs

  • 127 GRBs were added: 15 from 2024, 65 from 2025 and 47 from 2026. For 112 of them, the trigger time comes from SVOM.
  • 16 of the 17 GRBs that disappeared on 2026-08-17 are back (see the list below). GRB250427A is still missing, as no trigger time can be extracted from its circulars.
  • 78 GRBs that had a name generated by GRBweb (marked with *) now have their name from the literature, as they could now be matched with GCN circulars.
  • 18 names now refer to a different burst (see the list below). In most cases, a name from the literature had been given to a Fermi-GBM burst because the GRB with that name was missing. That Fermi-GBM burst now has another letter.
  • The position of 838 GRBs changed, by 0.2 arcsec for half of them and by more than 1 arcmin for 202 of them. 63 GRBs received a position error.
  • The T0 of 69 GRBs is now earlier, by up to 67 s, because SVOM or Einstein Probe detected them first. For most of them, the change is less than 2 s.
  • Corrections of individual GRBs: GRB260618B had a right ascension of 454° (typo in the IPN table), 9 GRBs had a position error of 0 (e.g. GRB130702A), the duplicate entry GRB250702FA was removed, the position errors of GRB070125A and GRB120630A were missing, and some circulars of GRB240727A and GRB240727D, GRB250317A and GRB250317B, and GRB250813A and GRB250813B were assigned to the wrong GRB.
GRBs that are back in the catalog (16)

GRB250106A, GRB250108A, GRB250314A, GRB250317B, GRB250327B, GRB250328A, GRB250329A, GRB250329B, GRB250419A, GRB250502A, GRB250507A, GRB250530A, GRB250610B, GRB250704A, GRB250706B, GRB250727A

Names that now refer to a different burst (18)
NameBefore (T0, Fermi name)Now (T0, Fermi name)
GRB240215CGRB240215C*, 16:05:23, GRB240215670GRB240215C, 19:51:43
GRB240914AGRB240914A*, 7:09:47, GRB240914298GRB240914A, 1:40:04
GRB241201AGRB241201A*, 13:31:58, GRB241201564GRB241201A, 14:55:59, GRB241201622
GRB241201BGRB241201B*, 14:55:59, GRB241201622GRB241201B*, 13:31:58, GRB241201564
GRB250317BGRB250317B*, 19:47:01, GRB250317824GRB250317B, 2:12:08
GRB250502AGRB250502A*, 7:23:59, GRB250502308GRB250502A, 8:46:29
GRB250521BGRB250521B*, 5:48:15, GRB250521242GRB250521B, 4:19:18
GRB250521CGRB250521C*, 13:31:01, GRB250521563GRB250521C*, 5:48:15, GRB250521242
GRB250910AGRB250910A*, 23:50:04, GRB250910993GRB250910A, 3:16:04
GRB251122AGRB251122A*, 23:44:26, GRB251122989GRB251122A, 13:57:08
GRB251211BGRB251211B*, 13:09:31, GRB251211548GRB251211B, 20:32:04, GRB251211856
GRB251211CGRB251211C*, 20:32:04, GRB251211856GRB251211C*, 13:09:31, GRB251211548
GRB260211AGRB260211A*, 21:24:26, GRB260211892GRB260211A, 19:24:33
GRB260531AGRB260531A*, 21:14:59, GRB260531885GRB260531A, 5:30:18
GRB260603AGRB260603A*, 16:44:25, GRB260603698GRB260603A, 5:38:16
GRB260705AGRB260705A*, 13:58:59, GRB260705583GRB260705A, 13:06:46
GRB260802AGRB260802A*, 8:59:47, GRB260802375GRB260802A, 9:23:10
GRB260822AGRB260822A*, 20:21:04, GRB260822848GRB260822A, 16:50:36

GRBs in the catalog: 9,218 before, 9,345 after · Last archived table before this update: version 01000 (2026-10-24)

2026-08-17

Full rebuild of the database

All tables taken from other catalogs were rebuilt from their latest versions. About 300 GRBs received updated values and 22 GRBs disappeared; 16 of these were restored on 2026-10-29.

What changed

  • During the daily updates, only new GRBs are added to the tables taken from other catalogs (Fermi-GBM, Swift, IPN, ...), while the values of GRBs that are already in GRBweb are not updated. These tables were now built again from the latest versions of the catalogs.
  • Recent corrections of the code now also apply to older GRBs, e.g. redshifts that are upper limits in the IPN table are no longer used.

Effect on the list of GRBs

  • About 300 GRBs, mostly from 2019–2026, received updated values from the Fermi-GBM, Swift and IPN catalogs: T90 or T100 (about 200 GRBs), position (about 140), fluence (about 90) and redshift (17).
  • 17 GRBs disappeared, most of them triggered by SVOM or Einstein Probe. Their trigger time and position came from the Swift GRB table, which no longer lists GRBs that were not triggered by Swift. The names of two of them, GRB250317B and GRB250502A, were then used for unrelated Fermi-GBM bursts. All but GRB250427A were restored on 2026-10-29.
  • GRB210114A*, GRB220201A*, GRB220225A* and GRB230909A* were removed, as they are no longer part of the Fermi-GBM burst catalog.
  • GRB220627B* was merged with GRB220627A, as both are Fermi-GBM triggers of the same burst.

GRBs in the catalog: 9,185 before, 9,164 after · Last archived table before this update: version 00940 (2026-08-03)

2026-07-29

Positions from IPN circulars corrected

IPN circulars that report a ring on the sky were read as if its centre were the position of the GRB. Correcting this changed the position of 34 GRBs and removed 2.

What changed

  • Positions are now only taken from IPN triangulation circulars that report an error box, and no longer from those that report an annulus.
  • On 2026-09-16, 14 entries of the IPN table with an incorrect position, e.g. a declination with the wrong sign, were excluded as well.

Effect on the list of GRBs

  • 34 GRBs received a different position, for most of them the localisation by Fermi-GBM.
  • GRB230712C and GRB240531A were removed, as their only position was such a ring.
  • The names of GRB121122A, GRB131126A, GRB190409B, GRB190504A and GRB200920B are now marked as generated by GRBweb (*), and the names GRB121122A–C and GRB190504A–B were reassigned among the bursts of those days.
  • On 2026-09-16, the positions of 10 more GRBs were corrected. Four of them, e.g. GRB241228B, had been given the same incorrect position.

GRBs in the catalog: 9,177 before, 9,176 after · Last archived table before this update: version 00930 (2026-07-18)

2026-03-19

Redshifts of three GRBs corrected

Thanks to a report by Saeeda Sajjad, the redshift of GRB100728B was corrected, the incorrect redshift of GRB120707A was removed and a redshift was added for GRB130528A.

What changed

  • GCN 13445 is no longer used. Its title refers to GRB120707A, but its text is about GRB120711A. It is a duplicate of GCN 13446 and was removed from the GCN archive.
  • For GRB100728B, the mean of the two redshifts listed in the Swift GRB table was used. The much more precise spectroscopic redshift from X-shooter at the VLT (GCN 11317) is now used instead.
  • The spectroscopic redshift of GRB130528A was added from the literature (doi:10.1051/0004-6361/201423979).

Effect on the list of GRBs

  • GRB120707A no longer has a redshift. The value of 1.405 came from GCN 13445 and is the redshift of GRB120711A.
  • The redshift of GRB100728B changed from 2.453 to 2.106.
  • GRB130528A received a redshift of 1.250.

GRBs in the catalog: 9,053 before, 9,054 after · Last archived table before this update: version 00840 (2026-03-17)

2026-01-27

Redshifts and durations checked against the literature

Redshifts and durations were checked by hand against papers and GCN circulars by Else Magnus. The redshift of 64 GRBs and the T90 of 36 GRBs were corrected or added, and 3 GRBs were added.

What changed

  • For these GRBs, the values found in the literature replace the ones that were extracted automatically. The reference of each value (DOI or GCN number) is listed on the page of the GRB.
  • GRB070125A, GRB120630A and GRB210116A, which are not listed in any of the catalogs used by GRBweb, were added by hand.

Effect on the list of GRBs

  • Redshift added for 42 GRBs and changed for 22 GRBs.
  • T90 and T100 added for 36 GRBs, 29 of them with an error on T90.
  • 3 GRBs added. Until 2026-10-29, the position errors of GRB070125A and GRB120630A were missing.

GRBs in the catalog: 9,006 before, 9,009 after · Last archived table before this update: version 00790 (2026-01-18)

2022-01-16

Names generated by GRBweb are marked with an asterisk

Fermi-GBM and BATSE GRBs that do not appear with a GCN-style name in the literature receive a name generated by GRBweb. These names are now marked with an asterisk (*).

What changed

  • A name ending with an asterisk was generated by GRBweb. Please refer to these GRBs by their Fermi or BATSE name.

Effect on the list of GRBs

  • 4,163 GRB names now end with an asterisk. Scripts that match GRBs by name may need to remove it.

GRBs in the catalog: 7,742 before, 7,749 after · Last archived table before this update: version 00200 (2021-11-20)

2020-11-27

Updated localisation errors of Fermi-GBM GRBs

The localisation errors of 227 Fermi-GBM GRBs from 2018–2020 were updated, most of them became smaller. 11 entries with a malformed name were removed.

What changed

  • Localisation error were updated based on newer Healpix files.
  • 11 Fermi-GBM bursts were listed with their Fermi name as GRB name (e.g. GRB091024380). These entries were removed, and the bursts are now listed under their GCN-style name.

Effect on the list of GRBs

  • 227 GRBs from 2018–2020 received a different localisation error: 192 smaller, 31 larger and 4 that had none.

GRBs in the catalog: 7,401 before, 7,393 after · Last archived table before this update: version 00140 (2020-10-07)

2020-05-18

Localisation errors for Fermi-GBM GRBs

For GRBs localised by Fermi-GBM, the 1σ localisation error is now derived from the HEALPix localisation maps of the Fermi-GBM team. 1,623 GRBs from 2008–2017 received a localisation error.

What changed

  • The 1σ error radius is extracted from the HEALPix localisation map of each GRB detected by Fermi-GBM.

Effect on the list of GRBs

  • 1,623 GRBs from 2008–2017 received a position error (pos_error), and the position of 8 GRBs changed.

GRBs in the catalog: 7,218 before, 7,222 after · Last archived table before this update: version 00110 (2020-04-06)

2019-11-05

Column t_trigger renamed to T0

The column t_trigger of the summary table is now called T0, and mjd (t_trigger) is now called mjd (T0). The values did not change.

What changed

  • T0 is the earliest time at which activity was reported from the GRB: the earliest trigger time of all instruments, or the start of the T90 interval if that is earlier.

Effect on the list of GRBs

  • No values changed, but scripts that select this column by name need to use the new name.

GRBs in the catalog: 7,056 before, 7,056 after · Last archived table before this update: version 00080 (2019-10-21)

2019-07-10

BeppoSAX catalog, Swift fluences and names for Fermi-GBM GRBs

The BeppoSAX catalog and the fluences of the Swift-BAT catalog were added, and Fermi-GBM GRBs that are not named in the literature now get a GCN-style name generated by GRBweb.

What changed

  • The BeppoSAX GRBM catalog (1996–2002) was added.
  • Fluences are now also taken from the Swift-BAT, BeppoSAX and BATSE catalogs.
  • Fermi-GBM GRBs that are not mentioned in GCN circulars were listed without a GCN-style name (None). They now get a name generated by GRBweb, using the first letter that is not used by another GRB of the same day. On 2019-07-22, these letters were reassigned in chronological order.

Effect on the list of GRBs

  • 530 GRBs were added, 516 of them from 1996–2002, mostly from the BeppoSAX catalog.
  • 1,705 Fermi-GBM GRBs that were listed without a GCN-style name now have a name generated by GRBweb.
  • Fluence added for 1,017 GRBs, most of them from the Swift-BAT catalog.
  • For about 300 GRBs from 1996–2000, the trigger time, position or T90 changed, as the values from BeppoSAX are now combined with those from BATSE.

GRBs in the catalog: 6,440 before, 6,970 after · Last archived table before this update: version 00030 (2019-05-13)

2019-02-22

GRBs from before 2008: BATSE and Swift

The catalog was extended to GRBs from before 2008, which are not covered by the GCN circulars used by GRBweb: 2,702 GRBs from the BATSE catalog (1991–2000) and 284 Swift GRBs (2004–2007) were added.

What changed

  • The BATSE catalog was added, which includes the GRBs of the 4B catalog and those found afterwards.
  • The Swift GRBs from 2004–2007 were added from the Swift GRB table.
  • On 2019-02-26, the declinations of 2,638 BATSE GRBs were corrected, as they had been read incorrectly when the catalog was added.

Effect on the list of GRBs

  • 2,986 GRBs were added.

GRBs in the catalog: 3,330 before, 6,322 after · Last archived table before this update: version 00010 (2019-02-14)