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"2405 results found.
- GRB 260618B: SVOM/VT continued optical observations indicated a steeper and redder decay
- GRB 260731A: AstroSat CZTI detection of a long burst
- GRB 260730B: NuSTAR detection of prompt emission
- GRB 260727A: SVOM/ECLAIRs refined analysis
- GRB 260726A: SVOM/ECLAIRs refined analysis
- GRB 260727A: AbAO and SAO RAS optical observations
- GRB 260726A: EP-FXT follow-up observations
- GRB 260727A: SVOM/GRM observation
- GRB 260726A: Fermi GBM Observation
- Konus-Wind detection of GRB 260727A
- GRB 260727A: Liverpool Telescope optical upper limits
- GRB 260727A: EP/FXT follow-up observations
- GRB 260727A: Glowbug gamma-ray detection
- GRB 260726A: J-band upper limit with WINTER
- GRB 260727A: J-band upper limit with WINTER
- GRB 260726A: SVOM/VT optical candidate
- GRB 260726A: SVOM ECLAIRs improved position and MXT possible detection of a counterpart
- GRB 260727A / SVOM sb26072702: RAPAS optical non-detection
- EP260723a: SVOM/ECLAIRs Upper Limit
- GRB 260727A: GOTO early optical upper limit
- GRB 260727A: AstroSat CZTI detection
- GRB 260727A: Kilonova-Catcher optical upper limit
- GRB 260727A: LCO optical upper limits
- GRB 260727A: SVOM detection of a bright long burst
- GRB 260726A: SVOM detection of a burst
- EP260723a: further EP-FXT follow-up observation
- GRB 260616A: cubesat Avion detection
- GRB 260601A: cubesat Avion detection
- EP260723a: EP-FXT follow-up observation
- GRB 260718A: SVOM/ECLAIRs refined analysis
- EP260723a: SVOM/VT optical observation
- Konus-Wind detection of GRB 260714B
- SVOM trigger sb26071506: SVOM/VT confirmation of a stellar flare
- GRB 260714B: Insight-HXMT/HE detection
- GRB 260718A: EP-FXT follow-up observation
- GRB 260718A: LCO optical upper limits
- GRB 260711A: SVOM/GRM observation
- GRB 260710A: SVOM/GRM observation
- GRB 260718A: Fermi GBM Observation
- GRB 260718A : GRANDMA and KNC upper limits
- GRB 260718A: SVOM/VT optical upper limits
- GRB 260718A: SVOM/VT optical upper limits from VHF data
- GRB 260718A: SVOM detection of a burst
- GRB 260714B: SVOM/GRM observation
- GRB 260618B: EP-FXT follow-up observation upper limit
- SVOM sb26071506: Global MASTER-Net observations report
- sb26071506: SVOM detection of a X-ray transient
- EP260703a: SVOM/ECLAIRs Upper Limit
- GRB 260709A: AstroSat CZTI detection
- GRB 260706A: ATCA detection of possible radio counterpart
- GRB 260705A: ATCA radio observations
- GRB 260619A: SVOM/VT continuous optical observations
- GRB 260618B: SVOM/VT optical observations indicate shallow decay and reddening
- GRB 260708A: GRANDMA Optical Observations
- GRB 260708A: LCO optical observations
- GRB 260709A: SVOM/GRM detection
- GRB 260704A: SVOM/ECLAIRs refined analysis
- GRB 260706A : GRANDMA Upper limits
- GRB 260705B: SVOM/GRM observation
- GRB 260706A: Further EP-FXT follow-up observation
- GRB 260706A: SVOM/VT optical upper limits
- GRB 260705A: Candidate Optical Counterpart from SOAR and Gemini-South and Possible Association with GRB 260705B
- GRB 260706A: SVOM/ECLAIRs refined analysis
- GRB 260704A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
- GRB 260706A: SVOM/GRM observation
- GRB 260706A: REM optical/NIR observations
- GRB 260706A: LCO optical upper limit
- GRB 260706A: EP-FXT follow-up observation
- GRB 260706A: Fermi GBM Observation
- GRB 260705A: SVOM/ECLAIRs refined analysis
- GRB 260706A: SVOM detection of a burst
- GRB 260705A: LCO optical upper limits
- GRB 260704A: NOT optical upper limits
- Fermi GBM Sub-Threshold Detection of GRB 260705A
- GRB 260705A: SVOM detection of a burst
- GRB 260704A: EP-FXT follow-up observation
- GRB 260629A: SVOM/GRM observation of a short burst
- GRB 260704A: SVOM detection of a possible GRB
- GRB 260614B: ATCA Radio Upper Limits
- MASS-Cube (GRID 2.0) detection of GRB 260616B
- GRB 260619A: SVOM/ECLAIRs refined analysis
- IPN triangulation of GRB 260605A
- EP260623a: SVOM/VT optical observations
- GRB 260616B/EP260616a: Insight-HXMT/HE detection
- GRB 260614B: EP-FXT follow-up observation
- GRB 260618C: SVOM/ECLAIRs detection of a possible burst through on-ground search
- GRB 260619A: NOT optical observations
- GRB 260618B: LCO optical observations
- GRB 260616B/EP260616a: SVOM/GRM detection of a burst
- GRB 260618B: Fermi GBM Observation
- GRB 260619A: TRT optical counterpart confirmation
- GRB 260610B: Further GRANDMA Optical Observations and re-brightening detection
- GRB 260604B: 239Alferov CubeSat detection
- GRB 260604A: 239Alferov CubeSat detection
- GRB 260610B: VLT/FORS2 spectroscopic observation suggests the non-thermal nature of the optical rebrightening
- GRB 260619A: SVOM/VT optical counterpart confirmation
- GRB 260618B: SVOM/VT optical candidate
- GRB 260618B: SVOM/VT optical candidate (duplicate Submission of 45001)
- GRB 260619A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
- GRB 260616A: SVOM/GRM observation