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').
9624 results found.
- Konus-Wind detection of GRB 240205B (long / very soft)
- GRB 240207A: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 240125A
- GRB 240205B: BOOTES-6 optical afterglow follow-up
- GRB 240204A: AstroSat CZTI detection
- GRB 240204A: Swift-BAT refined analysis
- Fermi trigger No 728749569: Global MASTER-Net observations report
- Swift GRB240205.93: Global MASTER-Net observations report
- GRB 240205A: Fermi GBM Final Real-time Localization
- GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
- Fermi trigger No 728706420: Global MASTER-Net observations report
- IceCube Alert 240204.38: Global MASTER-Net observations report
- Konus-Wind detection of GRB 240124B
- Konus-Wind detection of GRB 240123C
- GRB 240201A: AstroSat CZTI detection
- IPN triangulation of GRB 240125B (short)
- GRB 240129A: Swift/BAT-GUANO detection of a burst outside the coded FOV
- GRB 240128A: Swift-XRT observations
- GRB 240128A: MAXI/GSC detection
- GRB 240122A: ATCA detection of radio counterpart
- GRB 240125A: AstroSat CZTI detection of a short burst
- GRB 240124B: AstroSat CZTI detection
- GRB 240123C: AstroSat CZTI detection
- GRB 240125B: Fermi GBM Final Localization
- GRB 240123B: Swift/BAT-GUANO detection of a long burst
- Fermi-LAT gamma-ray observations of IceCube-240123A
- Fermi GRB 240123B: Global MASTER-Net observations report
- GRB 240123A: Swift-XRT refined Analysis
- GRB 240123A: Mondy optical afterglow observations
- Konus-Wind detection of GRB 240112A
- GRB 240123A: Swift detection of a burst with a possible optical counterpart
- Swift GRB240123.46: Global MASTER-Net observations report
- Konus-Wind detection of GRB 240119A (short/hard)
- GRB 240122A: MAXI/GSC detection
- GRB 240119A: GECAM detection of a short burst
- GRB 240119A: AstroSat CZTI detection of a short burst
- GRB 240118A: Swift-XRT afterglow detection
- Fermi GRB 240119A: Global MASTER-Net observations report
- GRB 240118C: Swift/BAT-GUANO detection of a burst
- GRB 240118D: AstroSat CZTI detection
- GRB 240117A: AstroSat CZTI detection
- Konus-Wind detection of GRB 240118A
- GRB 240118A: Fermi-LAT detection
- GRB 240115A: Swift/BAT-GUANO detection of a short burst
- IPN triangulation of GRB 240112A (long)
- GRB 240115B: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S240109a: Upper limits from Swift/BAT-GUANO
- Integral GRB240115.70: Global MASTER-Net observations report
- Fermi GRB 240115B: Global MASTER-Net observations report
- GRB 240115B: A long GRB detected by INTEGRAL
- Konus-Wind detection of GRB 240112C
- Fermi GRB 240115A: Global MASTER-Net observations report
- GRB 240114A: MAXI/GSC detection
- Fermi GRB 240112D: Global MASTER-Net observations report
- Fermi trigger No 726774492: Global MASTER-Net observations report
- Swift GRB 240112C: Global MASTER-Net observations report
- GRB 240112A: GECAM detection of a burst
- GRB 240110A: AstroSat CZTI detection
- Fermi-LAT detection of increased gamma-ray activity of blazar PKS 0446+11, located inside the IceCube-240105A error region
- Konus-Wind detection of GRB 240101C
- GRB 231215A: radio detection with the VLA
- LIGO/Virgo/KAGRA S240104bl: Upper limits from Swift/BAT-GUANO
- GRB 240107A: MAXI/GSC detection
- GRB 240106B: Fermi GBM Final Real-time Localization
- Fermi trigger No 726194053: Global MASTER-Net observations report
- IceCube Alert 240105.52: Global MASTER-Net observations report
- GRB 240102A: 1.3m DFOT optical upper limit
- GRB 240101C: Swift/BAT-GUANO detection of a short burst
- GRB 240102C: AstroSat CZTI detection
- GRB 240101C: AstroSat CZTI detection
- GRB 231230A: Swift-BAT refined analysis
- GRB 240101A: Swift-BAT refined analysis
- GRB 240102A: Swift-XRT refined Analysis
- GRB 240101A: Swift-XRT refined Analysis
- GRB 240101B: Swift detection of a burst
- GRB 240101A: Swift detection of a burst
- Fermi trigger No 725806648: Global MASTER-Net observations report
- GRB 231230A: Swift-XRT refined Analysis
- Fermi trigger No 725592555: Global MASTER-Net observations report
- GRB 231230A: Prompt enhanced Swift-XRT position
- GRB 231230A: Swift detection of a burst
- Swift GRB231230.06: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231224e: Upper limits from Swift/BAT-GUANO
- IPN triangulation of GRB 231224A (short)
- Fermi trigger No 725143760: Global MASTER-Net observations report
- GRB 231224A: Fermi GBM Final Real-time Localization
- LIGO/Virgo/KAGRA S231224e: Identification of a GW compact binary merger candidate
- GRB 231222B: Swift-XRT afterglow detection
- Fermi trigger No 724921799: Global MASTER-Net observations report
- GRB 231222B: Fermi-LAT detection
- IceCube-231211A: GRANDMA observations of PKS2047+098
- Fermi trigger No 724781422: Global MASTER-Net observations report
- GRB 231220A: Fermi GBM Final Real-time Localization
- GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
- Fermi trigger No 724698747: Global MASTER-Net observations report
- GRB 231216A: optical upper limits from the INAF Asiago Observatory
- GRB 231216A: 10.4 m GTC optical upper limit
- GRB 231216A: Nanshan/HMT optical upper limit
- GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
- GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit