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"28054 results found.
- GRB 230217A: Swift-BAT refined analysis
- IceCube-230217A: Upper limits from a search for additional neutrino events in IceCube
- GRB 230220A: MAXI/GSC detection
- Fermi-LAT gamma-ray observations of IceCube-230217A
- GRB 230217A: Swift-XRT observations
- GRB 230216B: AstroSat CZTI detection
- GRB 230217A: Swift detection of a short burst
- GRB 230216A: Swift-BAT refined analysis
- GRB 230216A: Swift-XRT refined Analysis
- GRB 230205A: Lowell Discovery Telescope Observations
- GRB 230204B: Lowell Discovery Telescope Observations
- GRB 230216A: Enhanced Swift-XRT position
- GRB 230216A: AKO Upper Limit
- GRB 230216A: Zadko observatory - Gingin optical observations
- GRB 230216A: Swift detection of a burst
- GRB 230209B: Fermi GBM Observation
- IPN triangulation of GRB 230209B
- GRB 230204B: ATCA radio detection
- GRB 230209B: Swift/BAT-GUANO detection outside the coded FOV
- Swift Trigger 1153670 is probably not a GRB
- GRB 230205A: SUBARU HSC pre-imaging for host galaxy search
- GRB 221009A: Continued Swift Observations
- GRB 230205A: possible host galaxy detection with the Schmidt - Asiago telescope
- GRB 230204B: MASTER early OT detection
- GRB 230207B: Swift/BAT-GUANO detection outside the coded FOV
- ZTF23aabmzlp/AT2023azs: Neil Gehrels Swift Observatory X-ray observations
- GRB 230207B: AGILE detection of a burst
- GRB 230204B: LCOGT Optical Upper Limits
- GRB 230204B: Swift/UVOT Upper Limits
- GRB 230205A: Swift/UVOT Upper Limits
- GRB 230204B: Fermi GBM detection
- GRB 230205A: LCOGT Optical Upper Limits
- GRB 230204B: Swift-XRT afterglow detection
- GRB 230204B: 3.6m DOT optical observation
- GRB 230205A: OHP/T193 optical observations
- GRB 230205A: Swift-BAT refined analysis (T90 = 2.3 s)
- GRB 230204A: Swift-BAT refined analysis
- GRB 230204B: ATLAS detection of the optical afterglow and a projected location in a nearby galaxy group
- GRB 230205A: Swift-XRT refined Analysis
- GRB 230205A: Enhanced Swift-XRT position
- GRB 230205A: Swift detection of a burst
- GRB 230204B: GIT discovery of the likely optical afterglow
- GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
- GRB 230204A: Swift/UVOT Upper Limits
- GRB 230204B: MAXI/GSC detection
- GRB 230204A: Swift-XRT refined Analysis
- GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
- GRB 230204A: Enhanced Swift-XRT position
- GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
- GRB 230201B: TURBO Optical Upper Limits
- IceCube-230201A: Upper limits from a search for additional neutrino events in IceCube
- ZTF23aabmzlp/AT2023azs: Lulin 1m LOT optical observations
- GRB 221216A: Swift-BAT refined analysis
- ZTF23aaarlti/AT2023avj: AMI-LA radio detection
- ZTF23aabmzlp/AT2023azs: AMI-LA radio upper limit
- IceCube Alert 230201.26: Global MASTER-Net observations report
- Fermi-LAT gamma-ray observations of IceCube-230201A
- GRB 230201B: Fermi GBM Final Real-time Localization
- GRB 230126A: Detection by VZLUSAT-2
- GRB 221009A: radio afterglow detection with the EVN
- GRB 230201A: Fermi GBM Final Real-time Localization
- ZTF23aabmzlp/AT2023azs: LCOGT Optical Detection
- AT2023avj: X-ray Detection with Swift/XRT
- ZTF23aabmzlp/AT2023azs: GIT confirmation of the likely afterglow
- ZTF23aabmzlp/AT2023azs: Zwicky Transient Facility discovery of a fast optical transient
- ZTF and LT Observations of AT2023avj, a Candidate Optical Afterglow
- Swift-XRT observations of NuEm-230125A
- Trigger 1150965: Swift detection of LS V +44 17
- GRB 230124A: Fermi GBM Observation
- GRB 230124A: Swift/BAT-GUANO detection outside the coded FOV
- IceCube-230122A: Upper limits from a search for additional neutrino events in IceCube
- GRB 230114B: Detection by VZLUSAT-2
- GRB 230123A: LCOGT Optical Upper Limits
- GRB 230123A: Swift-BAT refined analysis
- GRB 230122A: Swift/BAT-GUANO detection
- Fermi-LAT gamma-ray observations of IceCube-230122A
- GRB 230123A: Swift/UVOT Upper Limits
- GRB 230123A: Swift-XRT refined Analysis
- GRB 230123A: Enhanced Swift-XRT position
- GRB 230123A: Zadko observatory - Gingin optical observations
- GRB 230116C: Swift-XRT observations
- GRB 230123A: Swift detection of a burst
- Trigger 1150107: Swift detection of LS V +44 17
- GRB 230116D: 3.6m DOT optical upper limit
- GRB 230116D: Swift-BAT refined analysis
- GRB 230116C: Swift-BAT refined analysis
- GRB 230116D: SAO RAS further observations
- GRB 230116D: KGO RC-25 optical observations
- GRB 230116D: LCOGT Optical Upper Limit
- GRB 230116D: Swift-XRT refined Analysis
- GRB 230116D: GIT optical follow-up
- GRB 230116D: Enhanced Swift-XRT position
- GRB 230116D: SAO RAS observations of OT brightening
- GRB 230116D: Nanshan/NEXT optical afterglow detection
- GRB 230116D: Swift detection of a burst
- GRB 230114A: Detection by VZLUSAT-2
- Fermi-LAT gamma-ray observations of IceCube-230112A
- Fermi-LAT Gamma-ray Observations of IceCube-Cascade-230109A
- Fermi-LAT Gamma-ray Observations of IceCube-Cascade-221229A
- IceCube-230112A: Upper limits from a search for additional neutrino events in IceCube