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"2408 results found.
- EP260314a: COLIBRÍ optical upper limit
- EP260314a: refined analysis of the EP-WXT and EP-FXT observations
- EP260314a: BOOTES-6/DPR optical upper limits at early times
- EP260314a: SVOM/VT optical candidate
- GRB 260308A: Insight-HXMT/HE detection
- GRB 260308A: SVOM/GRM observation of a short GRB
- GRB 260307B: SVOM/ECLAIRs refined analysis
- GRB 260208A: radio detection with the VLA
- Fermi GBM Sub-Threshold Detection of GRB 260307B
- GRB 260307B: Mephisto optical upper limits
- GRB 260307B: possible NOT optical counterpart
- GRB 260307B: SVOM/VT upper limit with X band data analysis
- GRB260307B: GROWTH-India Telescope optical upper limit
- GRB 260307B: SVOM/VT optical candidate
- GRB 260307B: SVOM/C-GFT upper limit
- GRB 260307B: SVOM detection of a burst
- GRB 260211A: late-time NOT i-band observations consistent with archival flux
- EP260302a: SVOM/VT optical observation
- EP260306a: SVOM/VT optical observation
- GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
- GRB 260303A: 1.3m DFOT optical upper limit
- GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
- GRB 260303A: SVOM/ECLAIRs refined analysis
- SVOM/sb26030408: SVOM detection of an X-ray transient likely associated with Beta Persei
- GRB 260303A: SVOM/VT optical observations
- GRB 260228A: SVOM/ECLAIRs refined analysis
- GRB 260225A: SVOM/ECLAIRs refined analysis
- GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
- GRB 260303A: SVOM detection of a burst
- GRB 260228A: EP-FXT follow-up observation
- GRB 260228A: CAHA 2.2m telescope optical upper limit
- GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
- GRID detection of GRB 260225D
- EP260227a: SVOM/VT optical observation
- GRB 260228A: SVOM/VT optical upper limits
- GRB 260225D: SVOM/GRM observation
- GRB 260225B: SVOM/GRM observation
- GRB 260228A: SVOM detection of a burst
- GRB 260225A: SVOM/VT optical continued observations and upper limit
- GRID detection of GRB 260223A
- GRB 260225A: WINTER J-band upper limit
- EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
- GRB 260225D: Glowbug gamma-ray detection of a likely short burst
- GRB260225A: SVOM/ECLAIRs refined position
- GRB 260225A: EP-FXT follow-up observation
- GRB 260225A: SVOM/VT optical observation
- GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
- GRB 260223A: Fermi GBM Observation
- GRB 260225A: SVOM/VT optical upper limits
- GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
- GRB 260225A: SVOM detection of a burst
- GRB 260223A: Glowbug gamma-ray detection
- sb26021801: SVOM/VT optical upper limits
- GRB 260223A: COLIBRÍ optical afterglow decay confirmation
- sb26021801: SVOM/C-GFT upper limit
- GRB 260223A: SVOM/VT optical observation
- GRB 260223A: SVOM/GRM observation
- SVOM alert sb26021801: LCO optical upper limit
- SVOM alert sb26021801: LAST optical upper limit
- sb26021801: SVOM/COLIBRÍ (FM-GFT) optical upper limit
- GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
- sb26021801: SVOM detection of a long faint X-ray transient
- Konus-Wind detection of GRB 260212A
- IPN triangulation of GRB 260212A
- EP260214b: SVOM/VT optical observation
- EP260214a: COLIBRÍ optical upper limits
- EP260214a: refined analysis of the EP-FXT observation
- GRB 260211A: SVOM/VT optical counterpart
- EP260214a: SVOM/VT optical upper limits
- GRB 260212A: Fermi GBM Observation
- GRB 260212A: GECAM-B observation
- EP260213a: SVOM/VT optical upper limit
- EP260213a: SVOM/C-GFT upper limit
- GRB 260212A: SVOM/GRM observation of a long burst
- GRB 260211A - SVOM/ECLAIRs refined analysis
- GRB 260204A: SVOM/ECLAIRs refined analysis
- GRB 260211A: EP-FXT follow-up observation
- GRB 260211A: SVOM/VT optical observation
- GRB 260211A: GOTO optical upper limit
- GRB 260211A: LAST optical upper limit
- GRB 260210A: SVOM/GRM observation
- Fermi GBM Sub-Threshold Detection of GRB 260211A
- GRB 260128B: SVOM/ECLAIRs refined analysis
- GRB 260211A: LCO optical upper limits
- GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
- GRB 260211A: SVOM detection of a burst
- GRB 260210A: Glowbug gamma-ray detection
- EP260210a: SVOM/VT optical upper limit
- GRB 260210A: AstroSat CZTI detection
- GRB 260208C: AstroSat CZTI detection
- EP260210a: SVOM/C-GFT upper limit
- GRB 260208C: SVOM/GRM observation
- GRB 260204A: Swift-XRT afterglow detection
- GRB 260208B: AstroSat CZTI detection of a bright long burst
- GRB 260204A: Swift/UVOT Upper Limits
- GRB 260208B: COLIBRÍ optical observations
- GRB 260208B: EP-FXT observation
- GRB 260208B: SVOM/VT optical candidate
- GRB 260208A: SVOM/VT optical observation
- GRB 260208B: SVOM/GRM observation of a bright burst