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"
28692 results found.
- GRB 200809B: Swift-XRT afterglow detection
- GRB 200809B: MAXI/GSC detection
- GRB 200809B: Swift ToO observations
- GRB 200809B: AstroSat CZTI detection
- GRB 200809B: Swift/BAT-GUANO detection and arcminute localization
- GRB 200808A: AGILE detection
- GRB 200806A: CALET Gamma-Ray Burst Monitor detection
- Fermi GRB 200808A: Global MASTER-Net observations report
- GRB 200806A: Nanshan/NEXT optical upper limit
- IPN triangulation of GRB 200805A (short)
- GRB 200806A: CAHA optical afterglow confirmation
- GRB 200803A: Chilescope optical upper limit
- GRB 200806A: VIRT optical observations
- GRB 200806A: Swift-BAT refined analysis
- GRB 200806A: Swift/UVOT Possible Detection
- GRB 200806A: Swift-XRT refined Analysis
- Fermi-LAT Gamma-ray Observations of IceCube-200806A
- CGBM-SPI-ACS triangulation of short GRB 200805A
- GRB 200806A: AbAO optical upper limit
- GRB 200805A: CALET Gamma-Ray Burst Monitor detection of a short burst
- GRB 200806A: AstroSat CZTI detection
- GRB 200806A: MITSuME Akeno optical upper limits
- IceCube-200806A: Upper limits from Fermi-GBM Observations
- Swift GRB 200806A: Global MASTER-Net observations report
- GRB 200803B: MASTER possibly OT discovery
- GRB 200803A: AstroSat CZTI detection
- GRB 200803A: Fermi GBM detection
- GRB 200803A: Swift-XRT afterglow detection
- Fermi GRB 200803B: Global MASTER-Net observations report
- GRB 200803A: Fermi-LAT detection
- GRB 200803A: MASTER optical counterpart discovery
- GRB 200803A: Tiled Swift observations
- Fermi GRB 200803A: Global MASTER-Net observations report
- GRB 200801B: AstroSat CZTI detection
- Fermi GRB 200801B: Global MASTER-Net observations report
- Fermi GRB 200802A: Global MASTER-Net observations report
- AX J1846.4-0258: Swift-BAT refined analysis
- Konus-Wind detection of GRB 200729A
- Fermi GRB 200801A: Global MASTER-Net observations report
- GRB 200729A: RT-22 observations at 36.8 GHz
- GRB 200729A: VLA Observations
- GRB 200729A: Nanshan/NEXT optical upper limit
- GRB 200729A: Swift-BAT refined analysis
- GRB 200729A: further analysis of the NOT data
- GRB 200729A: Swift/UVOT Upper Limits
- GRB 200729A: Swift-XRT refined Analysis
- Fermi-GBM Sub-Threshold candidate for GRB 200729A
- GRB 200729A: Pan-STARRS pre-explosion source detection
- GRB 200729A: Spitzer archival source detection
- GRB 200729A: TNG NIR upper limits
- GRB 200729A: NOT optical upper limits
- Swift GRB 200729A: Global MASTER-Net observations report
- IceCube GCN Notice 134327_10548129 retraction
- GRB 200723A: ATLAS observations of GOTO candidate AT2020qer
- GRB 200723A: Swift ToO observations
- GRB 200723A: GOTO candidate afterglow and host galaxy
- Fermi GRB 200723A: Global MASTER-Net observations report
- GRB 200716C: Kitab optical observations
- GRB 200716C: CAHA optical observation // Anomalous light curve behavior?
- GRB 200716C: CrAO, Terskol, Assy-Turgen optical observations
- GRB 200714E: Swift-XRT afterglow detection
- GRB 200716C: FRAM-ORM afterglow detection
- Konus-Wind observation of GRB 200716C: correction to GCN 28147
- Konus-Wind observation of GRB 200716C
- GRB 200716C: VIRT optical detection.
- GRB 200716C: Insight-HXMT/HE detection
- AMON IC_HAWC 170720: Correction to ANTARES GCN 28142
- Fermi GRB 200718A: Global MASTER-Net observations report
- AMON IC_HAWC 170720: No Neutrino Counterpart detected with ANTARES
- GRB 200716C: CALET Gamma-Ray Burst Monitor detection
- GRB 200716C: Optical observations from HCT
- GRB 200716B: Insight-HXMT/HE detection
- GRB 200716C: Swift-BAT refined analysis
- GRB 200716C: Fermi GBM detection
- Fermi GRB 200716A: Global MASTER-Net observations report
- GRB 200716C: AGILE/MCAL detection
- GRB 200716C: possible host galaxy from the SDSS
- GRB 200716C: Swift-XRT refined analysis correction
- GRB 200716C: Fermi-LAT detection
- GRB 200716C: Swift-XRT refined Analysis
- GRB 200522A: HST NIR counterpart confirmation
- Swift GRB200716C: Global MASTER-Net OT detection
- IPN triangulation of GRB 200716A
- GRB 200716A: Fermi GBM detection
- Fermi GRB 200716B: Global MASTER-Net observations report
- GRB 200716B: AstroSat CZTI detection
- GRB 200716A: AstroSat CZTI detection
- GRB 200716A: AGILE detection
- GRB 200715A: Swift-XRT afterglow detection
- GRB 200715A: Swift ToO observations
- GRB 200714E: Fermi GBM observation
- GRB 200714E: Swift-XRT observations
- Fermi GRB 200714E: Global MASTER-Net observations report
- GRB 200714E: AGILE detection
- GRB 200714E: Swift ToO observations
- GRB 200714E: Swift/BAT-GUANO detection and arcminute localization
- Fermi GRB 200714D: Global MASTER-Net observations report
- Fermi GRB 200714A: Global MASTER-Net observations report
- GRB 200522A: Candidate Optical/nIR Counterpart from Gemini and HST Imaging
- GRB 200713A: Swift-BAT refined analysis