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.
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"
24600 results found.
- GRB 240123A: Swift detection of a burst with a possible optical counterpart
- GRB 240122A: Swift-XRT afterglow detection
- GRB 240122A: GOTO optical counterpart candidate
- IPN triangulation of GRB 240119A (short)
- GRB 240119A: GECAM detection of a short burst
- GRB 240118C: GECAM-B detection of a long burst
- GRB 240119A: AstroSat CZTI detection of a short burst
- GRB 240118A: Mondy optical observations
- GRB 240118A: Swift-XRT afterglow detection
- GRB 240118C: Fermi GBM Observation
- IceCube-240105A: Detection of NIR flare of PKS 0446+11 with WINTER
- GRB 240118C: Swift/BAT-GUANO detection of a burst
- GRB 240118D: AstroSat CZTI detection
- GRB 240118A: AbAO optical upper limit
- GRB 240118A: NuSTAR Offline Analysis of the GRB
- GRB 240117A: Glowbug gamma-ray detection
- GRB 240118A: Swift/BAT-GUANO detection of a burst outside the coded FOV
- GRB 240118C: BALROG localization (Fermi Trigger 727291408 / GRB 240118725)
- GRB 240118A: Fermi GBM Observation
- GRID detection of GRB 231230A
- GRB 240115A: Swift/BAT-GUANO detection of a short burst
- Swift Triggers 1209369 and 1209370 are not astrophysical events
- GRB 240115B: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S240109a: Upper limits from Swift/BAT-GUANO
- GRB 240115B: Fermi GBM Detection
- GRB 240112D: Glowbug gamma-ray detection
- GRB 240112C: Glowbug gamma-ray detection
- GRB 240112C: VZLUSAT-2 detection
- GRB 240114A: MAXI/GSC detection
- GRB 240112C: Swift/UVOT Detection
- GRB 240112C: Fermi GBM Detection
- Fermi trigger No 726773850: Global MASTER-Net observations report
- GRB 240112C: Swift-XRT refined Analysis
- GRB 240112C: SAO RAS optical observations
- GRB 240109A: Swift-BAT refined analysis
- GRB 240112C: Swift detection of a burst with an optical counterpart
- GRB 240112A: GECAM detection of a burst
- GRB 240109A: Fermi GBM Observation
- Fermi-LAT detection of increased gamma-ray activity of blazar PKS 0446+11, located inside the IceCube-240105A error region
- GRB 240108A: Glowbug gamma-ray detection
- GRB 240106B: Glowbug gamma-ray detection
- GRB 240106A: Glowbug gamma-ray detection
- IceCube-240105A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S240109a: Updated Sky localization
- GRB 231215A: radio detection with the VLA
- GRB 230818A: further radio observations with the VLA
- GRB 230812B: further radio observations with the VLA
- Swift GRB240109.17: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S240109a: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S240104bl: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240107b: Updated Sky localization and Source Classification
- GRB 240107A: MAXI/GSC detection
- LIGO/Virgo/KAGRA S240107b: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 240101C (short)
- GRB 240101A: 1.3m DFOT optical observations
- GRB 240102A: 1.3m DFOT optical upper limit
- GRB 240101B: 1.3m DFOT optical upper limit
- GRB 240101C: Swift/BAT-GUANO detection of a short burst
- LIGO/Virgo/KAGRA S240104bl: Updated Sky localization
- LIGO/Virgo/KAGRA S240104bl: Identification of a GW compact binary merger candidate
- GRB 240102A: Swift-BAT refined analysis
- GRB 240102A: Swift/UVOT Upper Limits
- GRB 231230A: Swift-BAT refined analysis
- GRB 240101A: Swift-BAT refined analysis
- GRB 240101B: Swift-BAT refined analysis
- GRB 240102A: Enhanced Swift-XRT position
- GRB 240101B: Swift-XRT refined Analysis
- GRB 240102A: Swift-XRT refined Analysis
- GRB 240102A: LCOGT Optical Upper Limits
- GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
- IceCube-Cascade 231230A: Upper limits from a search for additional neutrino events in IceCube
- GRB 240102A: Swift detection of a burst
- GRB 240101C: GRBAlpha detection
- GRB 240101B: Swift/UVOT Upper Limits
- GRB 240101A: Swift/UVOT Upper Limits
- GRB 240101A: Swift-XRT refined Analysis
- GRB 240101B: Enhanced Swift-XRT position
- GRB 240101A: Enhanced Swift-XRT position
- GRB 240101B: Swift detection of a burst
- LIGO/Virgo/KAGRA S231231ag: Updated Sky localization and Source Classification
- LIGO/Virgo/KAGRA S231231ag: Identification of a GW compact binary merger candidate
- GRB231230A: Fermi GBM Observation
- GRB 231230A: Swift-XRT refined Analysis
- GRB 231230A: Enhanced Swift-XRT position
- GRB 231230A: Swift/UVOT Upper Limits
- GRB 231230A: NOT optical upper limits
- GRB 231230A: Swift detection of a burst
- LIGO/Virgo/KAGRA S231224e: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231226av: Updated Sky localization
- LIGO/Virgo/KAGRA S231226av: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231224e: Updated Sky localization and Source Classification
- LIGO/Virgo/KAGRA S231224e: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231223j: Updated Sky localization
- GRB 231222B: Swift-XRT afterglow detection
- LIGO/Virgo/KAGRA S231223j: Identification of a GW compact binary merger candidate
- GRB 231222B: Fermi GBM Detection
- IceCube-231211A: GRANDMA observations of PKS2047+098
- GRID detection of GRB 231215A
- GRB 231220A: Swift-XRT follow-up observations
- GRB 231220A: Swift/BAT-GUANO arcminute localization of a long burst