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').
17086 results found.
- GRB 240205B: CALET Gamma-Ray Burst Monitor detection
- GRB 240205B: BOOTES-6 optical afterglow follow-up
- GRB 240205B: ATCA detection of radio counterpart
- GRB 240205B: REM detection of the optical/NIR afterglow
- GRB 240205B: Fermi GBM Observation
- GRB 240204A: AstroSat CZTI detection
- GRB 240205B: GECAM detection of a long burst
- GRB 240204A: Swift-BAT refined analysis
- GRB 240205B: Skynet Optical Afterglow Observations
- GRB 240205B: BOOTES-7 optical afterglow follow-up
- GRB 240205B: MASTER OT J232550.14-550704.6 counterpart detection
- GRB 240205B: Swift detection of a burst
- Swift GRB240205.93: Global MASTER-Net observations report
- GRB 240204A: Fermi GBM Observation
- GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
- GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
- GRB 240204A: Montarrenti Observatory optical observations
- GRB 240204A: Enhanced Swift-XRT position
- GRB 240204A: Mondy optical afterglow candidate
- GRB 240204A: Swift detection of a burst
- Swift Trigger 1212791 is not an astrophysical event.
- Swift-BAT triggers 1212787, 1212789 are not astrophysical.
- IPN triangulation of GRB 240124B
- GRB 240129A: Fermi GBM Observation
- GRB 240129A: Swift/BAT-GUANO detection of a burst outside the coded FOV
- IPN triangulation of GRB 240125A (short)
- GRB 240128A: Swift-XRT observations
- GRB 240128A: Tiled Swift observations
- GRB 240122A: ATCA detection of radio counterpart
- Swift Trigger 1211211 and 1211212 are not astrophysical
- GRB 240123C: AstroSat CZTI detection
- GRB240122A: PRIME near infrared detection
- GRB 240123B: Fermi GBM Observation
- GRB 240123A: Glowbug gamma-ray detection
- GRB 240123B: Swift/BAT-GUANO detection of a long burst
- GRB 240123A: GRBAlpha detection
- IPN triangulation of GRB 240123C (short)
- Swift trigger 1210856 is not astrophysical
- GRB 240123A: Swift-BAT refined analysis
- GRB 240123A : MITSuME Akeno optical afterglow candidate detection
- GRB 240123A: Enhanced Swift-XRT position
- GRB 240122A: Swift/UVOT Upper Limits
- GRB 240123A: Swift-XRT refined Analysis
- GRB 240122A: BOOTES-2/TELMA optical upper limit and 1.5m OSN detection
- Fermi GBM Sub-Threshold Detection of GRB 240123A
- GRB 240118A: Swift/UVOT Upper Limits
- GRB 240123A: Swift detection of a burst with a possible optical counterpart
- Swift GRB240123.46: Global MASTER-Net observations report
- GRB 240122A: Swift-XRT afterglow detection
- GRB 240122A: Tiled Swift observations
- IPN triangulation of GRB 240119A (short)
- GRB 240118C: GECAM-B detection of a long burst
- GRB 240118A: Mondy optical observations
- GRB 240118A: Swift-XRT afterglow detection
- GRB 240118C: Fermi GBM Observation
- GRB 240118C: Swift/BAT-GUANO detection of a burst
- GRB 240118A: GRBAlpha detection
- GRB 240115A: Fermi GBM Observation
- Swift triggers 1209631, 1209632, 1209635 and 1209644 are not interesting astrophysical events
- GRB 240118A: Swift ToO observations
- GRB 240118A: AbAO optical upper limit
- GRB 240118A: NuSTAR Offline Analysis of the GRB
- GRB 240118A: Swift/BAT-GUANO detection of a burst outside the coded FOV
- GRB 240118A: Fermi-LAT detection
- GRID detection of GRB 231230A
- GRB 240115A: Swift/BAT-GUANO detection of a short burst
- Swift Trigger 1209406 is not an astrophysical event
- Swift Triggers 1209401 and 1209403 are not astrophysical events
- Swift Triggers 1209371 through 1209374 are not astrophysical events
- Swift Triggers 1209369 and 1209370 are not astrophysical events
- LIGO/Virgo/KAGRA S240109a: Upper limits from Swift/BAT-GUANO
- GRB 240112C: Glowbug gamma-ray detection
- GRB 240112C: VZLUSAT-2 detection
- Konus-Wind detection of GRB 240112C
- GRB 240112C: GRBAlpha detection
- GRB 240112C: Swift/UVOT Detection
- GRB 240112C: Fermi GBM Detection
- GRB 240112C: Swift-XRT refined Analysis
- GRB 240112C: SAO RAS optical observations
- Swift GRB 240112C: Global MASTER-Net observations report
- GRB 240109A: Swift-BAT refined analysis
- GRB 240112C: Swift detection of a burst with an optical counterpart
- GRB 240109A: Fermi GBM Observation
- GRB 231214A: ATCA Radio Upper Limits
- Konus-Wind detection of GRB 240101C
- Swift GRB240109.17: Global MASTER-Net observations report
- GRB 240109A: Swift detection of a short burst
- LIGO/Virgo/KAGRA S240104bl: Upper limits from Swift/BAT-GUANO
- IPN triangulation of GRB 240101C (short)
- GRB GRB240101C: Fermi GBM observation
- 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
- GRB 231220A: Swift-UVOT upper limit
- 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