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"11519 results found.
- GRB 230307A: soft X-ray detection with LEIA
- GRB 230307A: Swift-XRT afterglow detection
- Further improved IPN localization for GRB 230307A
- GRB 230307A: SOAR/Goodman detection of the possible host galaxy
- GRB 230308A: CALET Gamma-Ray Burst Monitor detection
- GRB 230310A: AstroSat CZTI detection
- GRB 230307A: GECKO optical observations and detections of the afterglow
- GRB 230307A: MAXI/GSC upper limit
- GRB 230307A: Gemini-South Confirmation of the Optical Afterglow
- Fermi GRB 230310A: Global MASTER-Net observations report
- GRB 230310A: Fermi GBM Final Real-time Localization
- GRB 230307A: ATLAS information on the ULTRACAM optical afterglow candidate
- GRB 230308A: Fermi GBM detection
- GRB 230307A: Possible optical afterglow
- GRB 230307A: ASO-S/HXI detection
- GRB 230308A: AGILE/MCAL detection
- GRB 230307A: optical upper limit
- GRB 230307A: Upper limits from a neutrino search with IceCube
- GRB 230307A: Swift-XRT observations
- Fermi GRB 230307A: Global MASTER-Net observations report
- Konus-Wind detection of GRB 230307A
- Improved IPN localization for GRB 230307A
- GRB 230307A: VZLUSAT-2 detection
- GRB 230304B: CALET Gamma-Ray Burst Monitor detection
- Fermi GRB 230308A: Global MASTER-Net observations report
- GRB 230308A: BALROG localization (Fermi Trigger 699975152 / GRB 230308564)
- GRB 230308A: Fermi GBM Final Real-time Localization
- GRB 230307A: Tiled Swift observations
- GRB 230307A: Detection by GRBAlpha
- GRB 230305A: Detection by GRBAlpha
- GRB 230307A: BALROG localization (Fermi Trigger 699896651/ GRB 230307656)
- GRB 230307A: AstroSat CZTI detection
- GRB 230307A: possibly the second highest GRB energy fluence ever identified
- IPN triangulation of GRB 230307A (long/very bright)
- GRB 230307A: AGILE/MCAL detection
- GRB 230307A: Fermi GBM Observation of a very bright burst
- Fermi-LAT gamma-ray observations of IceCube-230306A
- GRB 230307A: Fermi GBM detection of a very bright GRB
- GRB 230307A: GECAM detection of an extremely bright burst
- GRB 230307A: Fermi GBM Final Real-time Localization
- Fermi trigger No 699811746: Global MASTER-Net observations report
- IceCube-230306A - IceCube observation of a high-energy neutrino candidate
- GRB 230304C: AstroSat CZTI detection
- GRB 230304B: AstroSat CZTI detection
- GRB 230304A: AstroSat CZTI detection
- GRB 230304B: Detection by GRBAlpha
- GRB 230304C: Fermi GBM Final Real-time Localization
- GRB 230304B: Fermi GBM Final Real-time Localization
- GRB 230304A: Fermi GBM Final Real-time Localization
- Fermi GRB 230301B: Global MASTER-Net observations report
- GRB 230301B: Fermi GBM Final Real-time Localization
- GRB 230228A: Fermi GBM Observation
- Fermi trigger No 699294715: Global MASTER-Net observations report
- Fermi trigger No 699311646: Global MASTER-Net observations report
- GRB 230301A: Fermi GBM Final Real-time Localization
- Fermi GRB 230227A: Global MASTER-Net observations report
- GRB 230227A: Fermi GBM Final Real-time Localization
- Fermi trigger No 699029364: Global MASTER-Net observations report
- GRB 230222A: Fermi GBM Final Real-time Localization
- Fermi-LAT gamma-ray observations of IceCube-230220A
- Fermi GRB 230220B: Global MASTER-Net observations report
- GRB 230217A: AstroSat CZTI detection
- GRB 230220B: Fermi GBM Final Real-time Localization
- IceCube-230220A - IceCube observation of a high-energy neutrino candidate
- GRB 230217A: Fermi GBM observation
- IceCube-230217A: BOOTES-4/MET Optical Observations
- Fermi-LAT gamma-ray observations of IceCube-230217A
- Konus-Wind detection of GRB 230217A
- Fermi trigger No 698427992: Global MASTER-Net observations report
- GRB 230218A is not a GRB
- GRB 230218A: Fermi GBM Final Real-time Localization
- GRB 230217A: AGILE/MCAL detection
- GRB 230216B: AstroSat CZTI detection
- GRB 230217A: Fermi GBM Final Real-time Localization
- IceCube-230217A - IceCube observation of a high-energy neutrino candidate track-like event
- Fermi GRB 230215A: Global MASTER-Net observations report
- GRB 230215A: Fermi GBM Final Real-time Localization
- GRB 230209B: AGILE detection
- GRB 230209B: Fermi GBM Observation
- IPN triangulation of GRB 230209B
- GRB 230204B: CALET Gamma-Ray Burst Monitor detection
- Outburst from LS V +44 17 / RX J0440.9+4431: Transient detection by GRBAlpha
- Fermi trigger No 697926015: Global MASTER-Net observations report
- Fermi trigger No 697904388: Global MASTER-Net observations report
- 230211A is not a GRB
- GRB 230211A: Fermi GBM Final Real-time Localization
- GRB 230209B: Swift/BAT-GUANO detection outside the coded FOV
- Fermi trigger No 697678542: Global MASTER-Net observations report
- GRB 230210A: Fermi GBM Final Real-time Localization
- Fermi GRB 230209B: Global MASTER-Net observations report
- GRB 230209B: Fermi GBM Final Real-time Localization
- GRB 230209A is not a GRB
- GRB 230209A: Fermi GBM Final Real-time Localization
- GRB 221009A: Continued Swift Observations
- Fermi Gamma-ray Burst Monitor trigger 230208382/697540213 is not a GRB
- GRB 230208A: Fermi GBM Final Real-time Localization
- Fermi Gamma-ray Burst Monitor triggers 230206723/697396830 and 230206797/697403223 are not GRBs
- Fermi GRB 230207A: Global MASTER-Net observations report
- GRB 230207A: Fermi GBM Final Real-time Localization
- Fermi trigger No 697403223: Global MASTER-Net observations report