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"27768 results found.
- GRB 230209B: Swift/BAT-GUANO detection outside the coded FOV
- Swift Trigger 1153670 is probably not a GRB
- GRB 230210A: Fermi GBM Final Real-time Localization
- GRB 230209B: Fermi GBM Final Real-time Localization
- GRB 230209A: Fermi GBM Final Real-time Localization
- GRB 221009A: Continued Swift Observations
- GRB 230207B: Detection by GRBAlpha
- GRB 230205A: possible host galaxy detection with the Schmidt - Asiago telescope
- GRB 230204B: MASTER early OT detection
- GRB 230208A: Fermi GBM Final Real-time Localization
- 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 230207A: Fermi GBM Final Real-time Localization
- GRB 230204B: Swift/UVOT Upper Limits
- GRB 230205A: Swift/UVOT Upper Limits
- GRB 230204B: Fermi GBM detection
- GRB 230204B: Swift-XRT afterglow detection
- GRB 230204B: 3.6m DOT optical observation
- GRB 230205A: SVOM/C-GFT optical upper limit
- GRB 230204B: VLT/X-shooter redshift
- 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 230204B: Swift ToO observations
- GRB 230205A: Enhanced Swift-XRT position
- GRB 230205A: BOOTES-5/JGT early optical upper limit
- GRB 230204B: Detection by GRBAlpha
- GRB 230204B: AGILE detection
- GRB 230205A: Swift detection of a burst
- GRB 230204B: GIT discovery of the likely optical afterglow
- GRB 230204B: AstroSat CZTI detection
- 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)
- ZTF23aabmzlp/AT2023azs: Lulin 1m LOT optical observations
- GRB 221216A: Swift-BAT refined analysis
- ZTF23aabmzlp/AT2023azs: VLA radio detection
- ZTF23aaarlti/AT2023avj: AMI-LA radio detection
- ZTF23aabmzlp/AT2023azs: AMI-LA radio upper limit
- GRB 230201B: Fermi GBM Final Real-time Localization
- GRB 230126A: Detection by VZLUSAT-2
- IceCube-230201A - IceCube observation of a high-energy neutrino candidate track-like event
- 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: 1.3m DFOT optical observations
- GRB 230129A: AstroSat CZTI detection
- GRB 230128A: AstroSat CZTI detection
- GRB 230130A: Fermi GBM Final Real-time Localization
- ZTF23aaarlti/AT2023avj: VLA radio detection
- GRB 230129A: Fermi GBM Final Real-time Localization
- GRB 230128A: Fermi GBM Final Real-time Localization
- ZTF23aabmzlp/AT2023azs: Zwicky Transient Facility discovery of a fast optical transient
- ZTF and LT Observations of AT2023avj, a Candidate Optical Afterglow
- GRB 230126A: Fermi GBM Final Real-time Localization
- 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
- GRB 230114B: Detection by VZLUSAT-2
- GRB 230124A: Fermi GBM Final Real-time Localization
- GRB 230123A: Swift-BAT refined analysis
- GRB 230122A: Swift/BAT-GUANO detection
- 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
- IceCube-230122A - IceCube observation of a high-energy neutrino candidate track-like event
- Trigger 1150107: Swift detection of LS V +44 17
- GRB 230120A: AstroSat CZTI detection
- IPN triangulation of GRB 230116B (short)
- GRB 230119A: CALET Gamma-Ray Burst Monitor detection
- GRB 230116D: 3.6m DOT optical upper limit
- GRB 230119A: Fermi GBM Final Real-time Localization
- GRB 230118A: Fermi GBM Final Real-time Localization
- GRB 230116D: Swift-BAT refined analysis
- GRB 230116C: Swift-BAT refined analysis
- GRB 230116D: Swift-XRT refined Analysis
- GRB 230117A: Fermi GBM Final Real-time Localization
- GRB 230116D: GIT optical follow-up
- GRB 230116D: Enhanced Swift-XRT position
- GRB 230116D: Sintez-Newton/CrAO optical afterglow detection
- GRB 230116D: Nanshan/NEXT optical afterglow detection
- GRB 230116D: Swift detection of a burst
- Swift GRB230116.88: Global MASTER-Net observations report
- GRB 230116C: Swift detection of a burst
- GRB 230116B: Fermi GBM Final Real-time Localization
- GRB 230116A: Fermi GBM Final Real-time Localization
- GRB 230114A: Detection by VZLUSAT-2
- GRB 230114A: Fermi GBM Final Real-time Localization
- Trigger 1148770: Swift detection of Cyg X-1 due to Star Tracker loss of lock