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"27781 results found.
- EP260812a: AZT-22 optical upper limit
- EP260806a: WFST optical observations
- EP260812b: Optical upper limit with Kinder
- GRB 260805D: SVOM/GRM detection of a possible magnetar burst
- GRB 260808B: Liverpool Telescope further optical observations
- GRB 260813A: BALROG localization (Fermi Trigger 808341387 / GRB 260813803)
- EP260812a: NOT and Liverpool Telescope upper limits:
- EP260812b: Liverpool Telescope observations
- EP260812b: GOTO detection of the optical counterpart
- EP260812a: refined analysis of the EP-WXT and autonomous EP-FXT observation
- EP260812a: SVOM/C-GFT optical upper limit
- EP260812b: COLIBRÍ optical observations
- EP260812b: SVOM/VT optical observation
- GRB 260808A: SVOM/GRM observation
- EP260812b: Einstein Probe detection of an X-ray transient
- EP trigger #01709278129 (EP260812b?): NOT optical counterpart
- Fermi GBM Sub-Threshold Detection of GRB 260809A
- GRB 260810A: Glowbug gamma-ray detection
- GRB 260808B: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical rebrightening
- GRB 260810A: AstroSat CZTI detection of a long burst
- EP260812a: Einstein Probe detection of an X-ray transient
- GRB 260809A: SAO RAS optical observations
- GRB 260808B: SAO RAS optical observations
- GRB 260317A: SVOM/ECLAIRs detection through offline targeted search and its possible association to magnetar 1E 1841-04.5
- EP260806a: MAO/AZT-22 optical observations
- IceCube-260807A: Upper limits from a search for additional neutrino events in IceCube
- GRB260808B: MAO/AZT-22 optical observations
- GRB 250607A: SVOM/ECLAIRs detection through offline targeted search
- GRB 260809A: J-band upper limit with WINTER
- GRB 260806A: Glowbug gamma-ray detection
- GRB260809A/EPF_J234751.2+210212: EP-FXT follow-up observation
- GRB 260809A: SVOM/COLIBRÍ (FM-GFT) optical observation
- GRB 260808B: SVOM/COLIBRÍ (FM-GFT) optical observation
- GRB 260809A: NOT optical observations
- GRB260809A: MAO/AZT-22 optical observations
- GRB260809A: OHP/T193 optical observations
- IceCube-260805A: Upper limits from a search for additional neutrino events in IceCube
- EP260809a: J-band upper limit with WINTER
- GRB 260808B: J-band upper limit with WINTER
- EP260809a:refined analysis of the EP-WXT and autonomous EP-FXT observation
- GRB 260809A: SVOM detection of a faint burst
- GRB 260808B: Liverpool Telescope optical observations
- GRB 260808B: NOT optical observations
- GRB 260808B: LCO optical observations
- GRB 260808A: NuSTAR detection of prompt emission
- EP260809a: COLIBRÍ optical observations
- EP260809a: LCO optical observation
- EP260809a: OHP/T193 optical observations
- GRB260808B: OHP/T193 optical observations
- GRB 260808B / EPF_J230056.0+082842: EP-FXT follow-up observation
- EP260809a: Einstein Probe detection of an X-ray transient
- GRB 260808B: SVOM/VT optical candidate from VHF data ( localization correction for GCN 45317 )
- GRB 260808B: SVOM/VT optical candidate from VHF data
- GRB 260808B: SVOM detection of a faint burst
- GRB 260808A: BALROG localization (Fermi Trigger 807850307 / GRB 260808119)
- Fermi GRB 260808A: Global MASTER-Net observations report
- IceCube Alert 260807A: Global MASTER-Net observations report
- GRB 260807A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
- GRB 260807A: SVOM possible detection of a faint burst
- EP260806a: COLIBRÍ optical observations
- EP260806a: refined analysis of the EP-WXT and autonomous EP-FXT observations
- EP260806a: SVOM/VT optical observation
- EP260806a: Liverpool Telescope observations of the counterpart show a blue colour
- EP260731a: refined analysis of the EP-WXT and autonomous EP-FXT observations
- EP260806a: LCO likely optical counterpart
- EP260806a: Einstein Probe detection of an X-ray transient
- GRB 260715A: cubesat Avion detection
- GRB 260709A: cubesat Avion detection
- GRB 260708A: cubesat Avion detection
- GRB 260730B: Glowbug gamma-ray detection
- GRB 260805C: Glowbug gamma-ray detection
- GRB 260805B: Glowbug gamma-ray detection
- Fermi GRB 260805A: Global MASTER-Net observations report
- GRB 260804A: Glowbug gamma-ray detection
- GRB 260805B: BALROG localization (Fermi Trigger 807622617 / GRB 260805484)
- IceCube-Cascade 260801A: Upper limits from a search for additional neutrino events in IceCube
- GRB 260708A: LCO further optical observations show supernova features
- Fermi GRB 260802B: Global MASTER-Net observations report
- GRB 260802A / EP J223759.5+521421: EP-FXT follow-up observation
- GRB 260802A: SVOM/VT optical upper limits from VHF data
- GRB 260802A: LCO optical upper limits
- GRB 260802A / EP J223759.5+531421: SVOM/COLIBRÍ (FM-GFT) optical upper limit
- GRB 260802A/EP J223759.5+531421: SVOM detection of a possible magnetar burst
- Fermi-LAT Gamma-ray Observations of IceCube-260722A
- EP260731a: COLIBRÍ optical upper limit
- EP260731a: NOT optical upper limit
- GRB 260730B: NuSTAR detection of prompt emission
- EP260731a: Einstein Probe detection of an X-ray transient
- EP260728a: COLIBRÍ optical upper limit
- EP260729a: Einstein Probe detection of an X-ray transient
- EP260727a: SAO RAS optical observations
- GRB 260727A: AbAO and SAO RAS optical observations
- EP260728a: EP-FXT follow-up observation
- GRB 260726A: EP-FXT follow-up observations
- EP260728a: Einstein Probe detection of a fast X-ray transient
- GRB 260726A: Fermi GBM Observation
- EP260727a: 1.5m OSN optical counterpart detection
- EP260727a:refined analysis of the EP-WXT and EP-FXT observation
- EP260727a: OHP/T193 optical observations
- GRB 260726A: Liverpool Telescope optical observations