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').
3086 results found.
- GRB 240128A: Tiled Swift observations
- GRB 240128A: CALET Gamma-Ray Burst Monitor detection
- GRB 240128A: MAXI/GSC detection
- GRB 240122A: ATCA detection of radio counterpart
- GRB240122A: PRIME near infrared detection
- IceCube Alert 240123.48: Global MASTER-Net observations report
- GRB 240122A: Swift/UVOT Upper Limits
- GRB 240122A: BOOTES-2/TELMA optical upper limit and 1.5m OSN detection
- GRB 240122A: Swift-XRT afterglow detection
- GRB 240122A: VLT/X-shooter redshift confirmation
- GRB 240122A: Redshift from OSIRIS+/GTC
- GRB 240122A: LT non-detection of GOTO candidate counterpart confirms fading
- GRB 240122A: GOTO optical counterpart candidate
- GRB 240122A: Tiled Swift observations
- GRB 240122A: MAXI/GSC detection
- Swift triggers 1209631, 1209632, 1209635 and 1209644 are not interesting astrophysical events
- AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-240118A
- Swift Triggers 1209371 through 1209374 are not astrophysical events
- GRB 240107A: VZLUSAT-2 detection
- Fermi GRB 240115A: Global MASTER-Net observations report
- GRB 240114A: MAXI/GSC detection
- Fermi GRB 240112D: Global MASTER-Net observations report
- Konus-Wind detection of GRB 240101C
- GRB 231215A: radio detection with the VLA
- Swift GRB240109.17: Global MASTER-Net observations report
- GRB 240107A: AstroSat CZTI detection
- GRB 240107A: MAXI/GSC detection
- IPN triangulation of GRB 240101C (short)
- GRB GRB240101C: Fermi GBM observation
- GRB 240101C: Swift/BAT-GUANO detection of a short burst
- GRB 240101C: AstroSat CZTI detection
- GRB 240101C: GRBAlpha detection
- GRB 240101C: Fermi GBM Final Localization
- Swift GRB240101.85: Global MASTER-Net observations report
- Fermi trigger No 725806648: Global MASTER-Net observations report
- Fermi trigger No 725592555: Global MASTER-Net observations report
- Fermi trigger No 725143760: Global MASTER-Net observations report
- Fermi trigger No 724781422: Global MASTER-Net observations report
- GRB 231215A: AMI-LA radio detection
- GRB 231214A: Swift-BAT refined analysis
- GRB 231216A: BOOTES-2/TELMA optical upper limit
- GRB 231205B: VZLUSAT-2 detection
- GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
- GRB 231215A: Swift/UVOT Detection
- GRB 231210B: MeerLICHT afterglow observations
- IceCube Alert 231211.03: Global MASTER-Net observations report
- Fermi trigger No 723906955: Global MASTER-Net observations report
- IPN triangulation of GRB 231129C
- IPN triangulation of GRB 231205A
- Fermi trigger No 723581802: Global MASTER-Net observations report
- GRB 231129C: ASIM MXGS observation and localization
- GRB 231205B: Nanshan/HMT optical upper limit
- GRB 231205A: DDOTI Upper Limits on the Afterglow
- Fermi trigger No 723326169: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
- Fermi trigger No 723412808: Global MASTER-Net observations report
- Konus-Wind detection of GRB 231129C
- GRB 231129C: PROMPT optical upper limits for the MAXI/GSC X-ray counterpart and the MASTER afterglow candidate
- GRB 231129B: Swift-XRT observations
- GRB 231129C: AGILE detection
- GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
- GRB 231129A: Swift-BAT refined analysis
- GRB 231129C: MASTER OT detection
- GRB 231129C: Fermi-LAT detection
- GRB 231129C: GRBAlpha detection
- GRB 231129C: Glowbug gamma-ray detection
- GRB 231129C: GECAM-B detection of a bright burst
- GRB 231129C: AstroSat CZTI detection
- GRB 231129C: CALET Gamma-Ray Burst Monitor detection
- GRB 231129C: Fermi GBM Observation of a very bright GRB
- GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
- GRB 231129C: MAXI/GSC detection
- GRB 231129B: Tiled Swift observations
- GRB 231129B: MAXI/GSC detection
- Fermi trigger No 722653947: Global MASTER-Net observations report
- Fermi trigger No 722400249: Global MASTER-Net observations report
- GRB 231117A: GTC Near-Infrared Observations
- Konus-Wind detection of GRB 231020A
- GRB 231117A : MITSuME Akeno optical afterglow candidate detection
- LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
- Fermi trigger No 722039659: Global MASTER-Net observations report
- GRB 231115A : OHP/T120 optical upper limit
- GRB 231117A : MITSuME Akeno optical upper limits
- Fermi GRB 231115A: Global MASTER-Net observations report
- GRB 231113A (short): Glowbug gamma-ray detection
- LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
- Swift GRB231111.60: Global MASTER-Net observations report
- Fermi trigger No 721204446: Global MASTER-Net observations report
- Fermi GRB 231108A: Global MASTER-Net observations report
- Fermi GRB 231106A: Global MASTER-Net observations report
- GRB 231104A: NOT upper limit
- Fermi GRB 231103A: Global MASTER-Net observations report
- Swift GRB231104.07: Global MASTER-Net observations report
- GRB 231030B: AstroSat CZTI detection
- Fermi GRB 231030B: Global MASTER-Net observations report
- Fermi trigger No 720224759: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
- GRB 231020A: AstroSat CZTI detection