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"2406 results found.
- GRB 260827A: Insight-HXMT/HE detection
- GRB 260903A: SVOM detection of a soft faint burst
- EP260901a: SVOM/VT optical upper limits
- Konus-Wind detection of GRB 260829A
- GRB 260829A: SVOM/GRM observation
- GRB 260818A: ATCA detection of a candidate radio counterpart
- GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per
- GRB 260831B / sb26083106: SVOM/VT optical variability of V* GK Per
- SVOM trigger sb26083106 is not a GRB
- GRB 260831B: EP-FXT follow-up observation
- GRB 260831B: LCO optical upper limits
- GRB 260827A: SVOM/GRM observation
- GRB 260831B: SVOM detection of a possible burst
- GRB 260825A: SVOM/GRM observation of a long burst
- GRB 260818B: Further EP-FXT observation
- GRB 260818B: VLT optical and nIR observations
- GRB 260818B: TNG NIR observations
- GRB 260818B: 6 GHz VLA observations
- GRB 260818B: SVOM/VT optical upper limit and continuous observations
- GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
- GRB 260808B: SAO RAS observations of the optical rebrightening
- GRB 260807A: EP-FXT follow-up observations
- GRB 260822A: SVOM/ECLAIRs refined analysis
- GRB 260809A: SVOM/ECLAIRs refined analysis
- GRB 260822A: SVOM/VT optical upper limits
- GRB 260822A: PRIME near-infrared upper limits from multiple epochs
- GRB 260822A: EP/FXT follow-up observations
- GRB 260822A: the candidate optical afterglow is an unrelated type-Ia SN
- GRB 260818A: further EP-FXT observations and X-ray afterglow confirmation
- GRB 260822A: GOTO optical counterpart detection
- GRB 260822A: SVOM/VT optical detection of COLIBRÍ candidate
- GRB 260822A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
- GRB 260822A: LCO optical upper limits
- GRB 260822A: GROWTH-India Telescope Upper Limits
- GRB 260822A: GOTO optical upper limit
- GRB 260822A: SVOM detection of a short burst
- GRB 260818B: SVOM/C-GFT optical upper limit
- EP260731a: SVOM/ECLAIRs detection through offline targeted search
- GRB 260818B: SVOM/GRM observation
- GRB 260818B: Insight-HXMT detection
- GRB 260818B: EP-FXT follow-up observation
- GRB 260818A: J-band observations with WINTER
- GRB 260818B: SVOM/ECLAIRs refined analysis
- GRB 260818A: SVOM/ECLAIRs refined analysis
- GRB 260818B: NOT optical upper limits
- GRB 260810A: SVOM/GRM observation
- GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical upper limit
- GRB260818A: EP-FXT follow-up observation
- GRB 260818B: LCO optical upper limits
- GRB 260818B: SVOM detection of a short burst
- SVOM trigger sb26081806 is not a GRB
- GRB 260818A: LCO optical upper limits
- GRB 260818A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
- GRB 260818A: SVOM possible detection of a long and faint GRB
- EP260806a: SVOM/ECLAIRs detection through targeted search
- GRB 260805D: SVOM/GRM detection of a possible magnetar burst
- GRB 260808B: Liverpool Telescope further optical observations
- EP260812a: SVOM/C-GFT optical upper limit
- EP260812b: COLIBRÍ optical observations
- EP260812b: SVOM/VT optical observation
- GRB 260808A: SVOM/GRM observation
- Fermi GBM Sub-Threshold Detection of GRB 260809A
- GRB 260808B: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical rebrightening
- GRB 260809A: SAO RAS optical observations
- GRB 260808B: SAO RAS optical observations
- GRB 260808B: SVOM/VT optical re-brightening at day 3
- GRB 260317A: SVOM/ECLAIRs detection through offline targeted search and its possible association to magnetar 1E 1841-04.5
- GRB 260807A: SVOM/ECLAIRs refined analysis
- GRB260808B: MAO/AZT-22 optical observations
- GRB 250607A: SVOM/ECLAIRs detection through offline targeted search
- GRB 260809A: J-band upper limit with WINTER
- 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
- GRB 260809A: SVOM/VT optical counterpart
- GRB 260808B: J-band upper limit with WINTER
- GRB 260808B: SVOM/ECLAIRs refined analysis
- 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 260808B / EPF_J230056.0+082842: EP-FXT follow-up observation
- GRB 260808B: SVOM/VT optical afterglow confirmation
- 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 260807A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
- GRB 260807A: SVOM possible detection of a faint burst
- EP260806a: refined analysis of the EP-WXT and autonomous EP-FXT observations
- EP260806a: SVOM/VT optical observation
- GRB 260709A: cubesat Avion detection
- GRB 260708A: LCO further optical observations show supernova features
- GRB 260802A / EP J223759.5+521421: EP-FXT follow-up observation
- GRB 260802A / EP J223759.5+531421: SVOM/VT optical upper limit
- 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