GCN Circulars
GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"26053 results found.
- GRB 251117A: FTW Observations of Swift candidate X-ray sources
- GRB 251116C: SVOM/ECLAIRs refined analysis
- GRB 251117A: AstroSat CZTI detection
- GRB 251117A: Fermi GBM observation
- GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
- GRB 251115A: Swift-XRT observations
- GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
- GRB 251117A: Tiled Swift observations
- GRB 251117A: Fermi-LAT detection
- GRB 251116C: Swift/BAT arcminute localization of a burst
- GRB 251116C: Swift-XRT observations
- GRB 251116C: SVOM/VT optical upper limit
- GRB 251115A: Tiled Swift observations
- GRB 251115A: Fermi-LAT detection
- GRB 251112A: Swift-BAT refined analysis
- LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
- GRB 251112A: Swift/UVOT Upper Limits
- GRB 251112A: Swift-XRT refined Analysis
- Swift Trigger 1413695: a possible GRB 251112A
- GRB251111A: 1.3m DFOT optical upper limit
- GRB 251111A: Swift-XRT afterglow detection
- GRB 251111A: Swift-XRT observations
- GRB 251013C: Chandra X-ray observations and jet break detection
- GRB 251111A: KAIT optical upper limit
- GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
- GRB 251103B: Swift-BAT refined analysis
- GRB 251106A: Swift/UVOT Upper Limits
- GRB 251105A: AstroSat CZTI detection
- GRB 251106A: SVOM/COLIBRÍ (FM-GFT) fading of the optical counterpart
- GRB 251106A: Swift-XRT afterglow detection
- GRB 251106A: Kilonova-Catcher optical upper limit
- GRB 251106A: Swift/BAT arcminute localization of a burst
- GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
- GRB 251103B: AstroSat CZTI detection
- GRB 250920C: TERI Gamma-ray detection
- GRB 251105A: Fermi GBM Observation
- GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
- GRB 251103B: Swift/UVOT Upper Limits
- GRB 251103B: Fermi GBM observation
- GRB 251103A: Optical afterglow detection by ZTF’s public survey
- GRB 251103A: WFST optical observations
- EP251102a: OHP/T193 optical observations
- GRB 251103A: OHP/T193 optical observations
- GRB 251103A: Xinglong 2.16m optical detection
- GRB 251103A: KAIT optical observations
- GRB 251103B: Nanshan/HMT optical upper limit
- GRB 251013C: 7DT detection and Medium-band SED of Afterglow
- GRB 251103A: Swift/BAT-GUANO arcminute localization of a burst
- GRB 251103B: MITSuME Akeno optical upper limits
- GRB 251103B: Swift-XRT refined Analysis
- Swift GRB 251103B: Global MASTER-Net observations report
- GRB 251103B: GROWTH-India Telescope optical upper limits
- GRB 251103A: Kilonova-Catcher optical afterglow detection
- GRB 251103B: Enhanced Swift-XRT position
- GRB 251103B: Prompt enhanced Swift-XRT position
- GRB 251103B: Swift detection of a burst
- GRB 251103A: Swift/UVOT Detection
- GRB 251103A: Swift-XRT afterglow detection
- GRB 251025B: OHP/T193 optical upper limit
- GRB 251103A: GOTO optical afterglow detection
- GRB 251103A: NOT spectroscopic redshift z = 0.76
- GRB 251103A: BOOTES-2/TELMA optical afterglow
- GRB 251103A: LCO optical afterglow detection
- GRB 251103A: NOT optical afterglow candidate (duplicate submission)
- GRB 251103A: NOT optical afterglow candidate
- GRB 251031A: Fermi GBM Observation
- GRB 251031A: Swift/BAT-GUANO localization skymap of a burst
- GRB 251022A: Swift-XRT confirmation of fading
- GRB 251026B: LBT near-infrared observations
- GRB 250925A: VZLUSAT-2 detection
- GRB 251026A/EP251026a: SVOM/VT optical counterpart
- GRB 251028B: Fermi/GBM observation
- GRB 251028B: Swift/BAT-GUANO localization skymap of a burst
- GRB 251025B: GROWTH-India Telescope continued multiband optical observations and rebrightening
- GRB251025B: 3.6m DOT Optical Observations
- GRB 251025B: Swift-XRT confirmation of fading
- GRB 251013C : 3.4-m telescope of Iranian National Observatory (INO340) optical observations
- GRB 251026B: Swift-XRT observations of GOTO25jgl/AT2025absf
- GRB 251023B: Swift-UVOT Upper Limits
- GRB 251027A: Swift-XRT observations
- GRB 251022A: SVOM/GRM observation
- GRB 251026B: Swift ToO observations
- GRB 251017A: Mondy AZT-33IK and Koshka Zeiss-1000 optical observations
- GRB 251017A: INASAN-Kislovodsk optical observations
- GRB 251025B: Kilonova-Catcher optical afterglow detection
- GRB 251025B: VLT/MUSE spectroscopic redshift z = 2.003
- GRB 251025C: AstroSat CZTI detection
- GRB 251026A: Swift-XRT observations
- GRB 251025B: OHP/T193 optical detection
- GRB 251025B: SVOM/VT optical bump
- GRB 251025B: SVOM/COLIBRÍ (FM-GFT) strong rebrightening of the optical counterpart
- GRB 251025B: ULL-ASTRO-MASTER optical counterpart detection with IAC80 telescope at Teide Observatory
- GRB 251024A: Swift/UVOT Upper Limits
- GRB 251025B: Swift-XRT afterglow detection
- GRB 251024A: Swift-BAT refined analysis
- GRB 251024A: Swift-XRT refined Analysis
- GRB 251025A (sb25102501): Likely a stellar flare by SVOM/VT
- GRB 251003A: VLA Detection
- GRB 251024A: Enhanced Swift-XRT position
- GRB 251023C: Glowbug gamma-ray detection