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"11546 results found.
- GRB 230506C: Fermi GBM detection
- Fermi trigger No 705413051: Global MASTER-Net observations report
- Fermi Gamma-ray Burst Monitor trigger 230510133/705381054 is not a GRB
- GRB 230510A: Fermi GBM Final Real-time Localization
- GRB 230307A: JWST second-epoch observations
- Fermi-LAT gamma-ray observations of IceCube-230506A
- IceCube-230506A: IceCube observation of a high-energy neutrino candidate
- GRB 230506A: Fermi GBM Final Real-time Localization
- Fermi trigger No 704837952: Global MASTER-Net observations report
- GRB 230503A: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 230430A
- IPN triangulation of GRB 230430A (short)
- GRB 230430B: Fermi GBM Final Localization
- GRB 230430A: Fermi GBM observation
- GRB 230430A: AstroSat CZTI detection
- GRB 230430A: Fermi GBM Final Real-time Localization
- GRB 230426A: VZLUSAT-2 detection
- Fermi trigger No 704365743: Global MASTER-Net observations report
- GRB 230428A: Fermi GBM Final Real-time Localization
- GRB 230426A: MASTER OT J023135.16-792104.8 optical counterpart discovery
- GRB 230426A: Fermi GBM Detection
- GRB 230426A: AstroSat CZTI detection
- Fermi trigger No 704233744: Global MASTER-Net observations report
- GRB 230426A: Fermi GBM Final Real-time Localization
- GRB 230425A: Fermi GBM Final Real-time Localization
- GRB 230421A: Fermi GBM observation
- Konus-Wind detection of GRB 230418A
- GRB 230421: Swift/BAT-GUANO arcminute localization
- Duplicate of GCN 33668
- GRB 230421A: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 230418A (short)
- GRB 230418A: AstroSat CZTI detection
- GRB 230418A: AGILE detection
- GRB 230402A: Fermi GBM detection
- GRB 230419A: Fermi GBM Final Real-time Localization
- GRB 230418A: Swift/BAT-GUANO detection outside the coded FOV
- GRB 230418A: Fermi GBM Observation
- GRB 230402A: Fermi-LAT detection
- Fermi-LAT gamma-ray observations of IceCube-230416A
- GRB 230415A: Fermi GBM detection
- GRB 230415A: Swift/BAT-GUANO detection
- GRB 230307A: iTelescope optical upper limit (likely)
- IceCube-230416A: IceCube observation of a high-energy neutrino candidate
- Fermi trigger No 703284533: Global MASTER-Net observations report
- Fermi GRB 230414A: Global MASTER-Net observations report
- GRB 230414A: Fermi GBM Final Real-time Localization
- GRB 230328B: redshift lower limit estimating
- GRB 230409D: VZLUSAT-2 detection
- GRB 230410A: Fermi GBM Final Real-time Localization
- Fermi GRB 230409C: Global MASTER-Net observations report
- Fermi GRB 230409A: Global MASTER-Net observations report
- GRB 230409C: Fermi GBM Final Real-time Localization
- Fermi trigger No 702745263: Global MASTER-Net observations report
- GRB 230409A: Fermi GBM Final Real-time Localization
- GRB 230405B: VZLUSAT-2 detection
- Fermi-LAT gamma-ray observations of IceCube-230405A
- Konus-Wind detection of GRB 230405B
- GRB 230405B: AGILE detection
- GRB 230405B: Fermi GBM Observation
- GRB 230307A: JWST NIRSpec observations, possible higher redshift
- GRB 230307A: short mininum variability timescale compatible with a merger origin
- GRB 230405B: AstroSat CZTI detection
- GRB 230405B: Fermi GBM Final Real-time Localization
- GRB 230307A: JWST observations consistent with the presence of a kilonova
- Fermi GRB 230405A: Global MASTER-Net observations report
- IceCube-230405A: IceCube observation of a high-energy neutrino candidate
- GRB 230405A: Fermi GBM Final Real-time Localization
- GRB 230404A: AstroSat CZTI detection
- GRB 230404A: Fermi GBM Final Real-time Localization
- GRB 230402A: CALET Gamma-Ray Burst Monitor detection
- GRB 230402A: AstroSat CZTI detection
- Fermi-LAT gamma-ray observations of IceCube-230401A and detection of Fermi J0030.2+0005
- GRB 230307A: Chandra late-time detection of the X-ray afterglow
- GRB 230402A: AGILE detection
- Fermi GRB 230402A: Global MASTER-Net observations report
- GRB 230402A: Fermi GBM Final Real-time Localization
- IceCube-230401A: IceCube observation of a high-energy neutrino candidate
- GRB 230307A: Bad Time Intervals for Fermi GBM data
- GRB 230328B : GRANDMA/Kilonova-Catcher optical detection
- GRB 230328B: CAHA 2.2m/CAFOS detection
- GRB 230328B: 3.6m DOT multiband optical observation
- Fermi trigger No 701883729: Global MASTER-Net observations report
- GRB 230330B: Fermi GBM Final Localization
- Konus-Wind detection of GRB 230328B
- GRB 230328B: GRBAlpha detection
- GRB 230330A: Fermi GBM Final Real-time Localization
- GRB 230328B: Liverpool Telescope afterglow detection
- GRB 230328B: AstroSat CZTI detection
- GRB 230328B: Fermi GBM observation
- GRB 230328B: Fermi GBM Final Real-time Localization
- Fermi GRB 230328A: Global MASTER-Net observations report
- GRB 230328A: Fermi GBM Final Real-time Localization
- GRB 230320B: Fermi GBM Observation
- Fermi trigger No 701313046: Global MASTER-Net observations report
- Fermi trigger No 701321709: Global MASTER-Net observations report
- Konus-Wind detection of GRB 230308A
- Konus-Wind detection of GRB 230304B
- GRB 230322A: Fermi GBM Final Real-time Localization
- GRB 230320B: GRBAlpha detection
- GRB 230321A: CALET Gamma-Ray Burst Monitor detection