GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"155 results found.
- EP251222b/GRB 251222A: SVOM/GRM observation
- GRB 250914A: AstroSat CZTI detection
- Fermi GRB 250909A: Global MASTER-Net observations report
- GRB 250506A: Swift XRT observations and possible counterpart detection
- Integral GRB241215.58: Global MASTER-Net observations report
- GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
- GRB 241025A: Swift-XRT refined Analysis
- LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
- LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
- Fermi GRB 240407A: Global MASTER-Net observations report
- Fermi trigger No 722349867: Global MASTER-Net observations report
- GRB 230628E: Swift/UVOT Detection
- GRB 230628E: Swift detection of a burst
- LIGO/Virgo S230616s: Global MASTER-Net observations report
- GRB 220711B: Swift/UVOT Upper Limits
- Konus-Wind detection of GRB 220613A
- GRB 220610B: AstroSat CZTI detection
- Fermi GRB 220514A: Global MASTER-Net observations report
- Fermi GRB 220309A: Global MASTER-Net observations report
- GRB 211206A: AstroSat CZTI detection
- GRB 210709A: AstroSat CZTI detection
- MAXI GRB210709.93: Global MASTER-Net observations report
- Fermi trigger No 642538568: Global MASTER-Net observations report
- GRB 210104A: Swift/UVOT Detection
- Swift GRB201024.12: Global MASTER-Net observations report
- SGR 1830-0645: Swift/UVOT Upper Limits
- GRB 200928B: AstroSat CZTI detection
- IceCube-200806A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
- Fermi GRB 200607B: Global MASTER-Net observations report
- Swift GRB200303.11: Global MASTER-Net observations report
- Swift GRB200216.56: Global MASTER-Net observations report
- Konus-Wind observation of GRB 200120A
- GRB 200115A: CALET Gamma-Ray Burst Monitor detection
- GRB 190719C: Swift/UVOT Upper Limits
- GRB 180418A: TAROT La Silla observatory early optical observations
- GRB 180324A: Swift/UVOT Upper Limits
- Swift triggered on SAX J1806.5-221
- GRB 160409A found in Swift BAT ground analysis
- GRB 160327A: Swift/UVOT Upper Limits
- GRB 151027B: MASTER-NET early OT detection
- Trigger 659734: Swift detection of SAX J1750.8-2900 or other source near Galactic center
- Swift detection of SAX J1808.4-3658
- GRB 150222A: Swift-XRT refined Analysis
- GRB 141031A: Fermi GBM detection
- Swift detection of SAX J1712.6-3739
- GRB 140506A: Swift/UVOT Detection
- Konus-Wind observation of GRB 140213A
- GRB 130725B: Swift/UVOT Observations
- GRB 130725B: Swift/UVOT Detection of an Optical Counterpart
- Swift Trigger 558631: AAO optical observations
- GRB 130527A: Suzaku WAM observation of the prompt emission
- Swift-BAT trigger 536502 is not astrophysical
- Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
- Swift-BAT trigger 535733 is not astrophysical
- Trigger 535733: Swift possible detection of SAX J1828.5-1037
- GRB 120305A: Swift/UVOT Upper Limits
- Swift-BAT refined analysis of outburst from 1E 1841-04.5
- GRB 110128A: Swift/UVOT observations
- GRB101024A: Swift/UVOT
- GRB 081125: Fermi GBM detection
- GRB 080506: Enhanced Swift-XRT position
- SAX J1818.6-1703: Swift detection (trigger 306379)
- UVOT observations of SAXJ1810.8-2609
- Swift detection of a outburst from SAX J1810.8-2609
- GRB 060717: Swift detection of a burst
- Bright short hard GRB 060303: IPN localization and Konus spectrum
- GRB050813: SWIFT/UVOT observation
- GRB 050714B: refined XRT analysis
- H11603: An X-ray flare from V4641 Sgr, or a possible XRF
- BeppoSAX GRB : GRB020409
- GRB020322: Candidate Optical Afterglow
- Bepposax GRB020322 The second springtime BSAX GRB
- GRB 011211 Optical Observations: Likely Afterglow
- Detection of the X-ray afterglow of GRB011121 by BeppoSAX
- GRB011121: BeppoSAX-WFC refined positions
- BEPPOSAX GRB011121
- The X-ray Flash 011030 ('GRB 011030')
- IPN triangulation of GRB010629
- Support extension to the BeppoSAX mission
- GRB010222: possible optical counterpart
- GRB010222
- GRB 010214, Optical Observations
- GRB000528, Radio Observations
- IPN triangulation of GRB000516
- BeppoSAX GRB000424
- GRB000419 [IPN Position]
- 1SAXJ1715.0-7134 refined position
- RE: Budget cuts in BeppoSAX operations: impact on GRB observation
- X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
- Budget cuts in BeppoSAX operations: impact on GRB observations
- GRB000226 [IPN Position]
- GRB 000210: BATSE Observations
- GRB000210, Radio Observations
- SAX_WFC_GRB_NOTICE
- SAX_WFC_GRB_NOTICE
- GCN resumes full operations
- IPN error box for GRB991216
- GRB 991217 (SAX J2303.2+0015) Optical observations
- GRB991217/SAX J2303.2+0015, optical observations
- SAX J2303.2+0015 Optical observations