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"28091 results found.
- IPN triangulation of GRB 230512A
- GRB 230512A: Nanshan/NEXT non-detection of GRB afterglow candidate
- GRB 230512A: GIT non detection of afterglow candidate
- GRB 230512A: Kitab possible afterglow candidate
- Fermi trigger No 705565670: Global MASTER-Net observations report
- Fermi-LAT gamma-ray observations of IceCube-230511A
- GRB 230510A: OHP/T193 and OHP/T120 optical observations
- GRB 230512A: Swift-XRT observations
- IceCube-230511A: Upper limits from a search for additional neutrino events in IceCube
- IceCube-Cascade 230511A: Upper limits from a search for additional neutrino events in IceCube
- GRB 230512A: GIT optical follow-up ZTF candidates
- GRB 230512A: Fermi GBM detection
- GRB 230512A: Fermi-LAT detection
- GRB 230512A: Fermi GBM Final Localization
- GRB 230510A: GIT optical upper limits
- GRB 230510A: LCOGT Optical Upper Limit
- GRB 230510A: Swift/UVOT Observations
- GRB 230510B: AstroSat CZTI detection
- GRB 230510A: Fermi GBM detection
- Fermi trigger No 705446499: Global MASTER-Net observations report
- GRB 230510A: Gaoyazi/GOT optical upper limit
- GRB 230510A: Nanshan/NEXT optical afterglow detection
- GRB 230510B: MAXI/GSC detection
- GRB 230506B: Fermi GBM detection
- GRB 230510A: Swift-XRT refined Analysis
- GRB 230510A: Enhanced Swift-XRT position
- GRB 230506C: Fermi GBM detection
- GRB 230510A: Swift detection of a burst
- GRB 230506C: SAO RAS optical observations
- IceCube-230506A: Upper limits from a search for additional neutrino events in IceCube
- Fermi-LAT gamma-ray observations of IceCube-230506A
- GRB 230506C: Swift-XRT refined Analysis
- GRB 230506C: Swift-BAT refined analysis
- GRB 230506B: Swift-BAT refined analysis
- GRB 230506C: spectro-imaging observations of the optical afterglow with T193-OHP
- GRB 230506B: LCOGT Optical Upper Limits
- GRB 230506C: Swift/UVOT Upper Limits
- GRB 230506C: NUTTelA-TAO / BSTI Early Optical Limits
- GRB 230506B: Swift-XRT refined Analysis
- GRB 230506C: Swift-XRT analysis
- GRB 230506C: TSHAO possible afterglow candidate
- GRB 230506B: Swift/UVOT Detection
- GRB 230506B: Swift detection of a burst
- GRB 230506B: Swift detection of a burst
- GRB 230420A: Mondy optical afterglow detection, TSHAO, CrAO optical upper limit
- GRB 230427A: Swift-BAT refined analysis
- IceCube-Cascade 230430A: Upper limits from a search for additional neutrino events in IceCube
- GRB 230420A: AROMA-N Optical Upper Limit
- GRB 230427A: NOT optical upper limit
- GRB 230427A: TSHAO, SAO RAS, AbAO optical upper limit
- GRB 230427A: Swift/UVOT Detection
- GRB 230427A: Gaoyazi/GOT optical upper limit
- GRB 230427A: OHP/T193 spectroscopy observations of WISEA J101316.01+481158.7
- GRB 230427A: Nanshan/HMT optical upper limit
- GRB 230427A: Osservatorio Astronomico Nastro verde upper limit
- GRB 230427A: OSIRIS+/GTC observations
- GRB 230427A: Swift-XRT refined Analysis
- GRB 230426A: VZLUSAT-2 detection
- GRB 230427A: GIT optical upper limit
- GRB 230427A: Bassano Bresciano Observatory upper limit
- GRB 230427A: GMG upper limit
- GRB 230427A : OHP/T193 optical upper limit
- GRB 230423A(trigger #1165354): Swift-BAT refined analysis
- GRB 230427A: AKO Upper Limit
- GRB 230427A: MITSuME Akeno optical upper limits
- GRB 230426A: Fermi GBM Detection
- GRB 230427A: Enhanced Swift-XRT position
- GRB 230427A: Swift detection of a burst with an optical counterpart
- Fermi trigger No 704233744: Global MASTER-Net observations report
- GRB 230423A: Swift/UVOT Upper Limits
- GRB 230423A: Swift-XRT refined Analysis
- Swift Trigger 1165354 is probably not a GRB
- GRB 221009A: Late-time JWST Observations and Detection of Supernova Emission
- GRB 230421A: Fermi GBM observation
- GRB 230420A: Swift/UVOT Upper Limits
- GRB 230421: Swift/BAT-GUANO arcminute localization
- GRB230420A: VLT optical observation
- GRB 230420A: Swift-BAT refined analysis
- GRB 230420A: Swift-XRT refined Analysis
- GRB 230420A: MITSuME Akeno optical observation
- GRB 230420A: NOT optical afterglow confirmation
- GRB 230420A: Gaoyazi/GOT optical upper limit
- GRB 230420A: LCOGT Optical Upper Limit
- GRB 230420A: Enhanced Swift-XRT position
- GRB230414B: VIRT Optical Upper Limit
- IPN triangulation of GRB 230418A (short)
- GRB 230420A: Swift detection of a burst
- GRB 230402A: Fermi GBM detection
- GRB 230418A: Swift/BAT-GUANO detection outside the coded FOV
- GRB 230418A: Fermi GBM Observation
- IceCube-Cascade 230417A: Upper limits from a search for additional neutrino events in IceCube
- GRB 230402A: Fermi-LAT detection
- Fermi-LAT gamma-ray observations of IceCube-230416A
- GRB 230414B: Nickel and KAIT telescope optical observations
- GRB 230414B Swift-BAT refined analysis
- GRB 230415A: Fermi GBM detection
- GRB 230414B: Swift/UVOT Detection
- GRB 230414B: Osservatorio Astronomico Nastro Verde - Sorrento: optical observations
- IceCube-230416A: Upper limits from a search for additional neutrino events in IceCube
- GRB 230415A: Swift/BAT-GUANO detection