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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"- GRB 260515A: GTC/OSIRIS+ spectroscopic redshift z = 0.764
- GRB 260515A: LCO optical observations
- SVOM GRB 260515A: Global MASTER-Net observations report
- GRB 260515A: NOT optical observations.
- SVOM GRB 260515A: MASTER OT J151044.43+243321.7 optical counterpart detection
- GRB 260515A: SVOM/VT optical candidate from VHF data
- GRB 260515A: JinShan optical counterpart candidate
- GRB 260515A: SVOM detection of a burst
- GRB 260510C: Glowbug gamma-ray detection
- IceCube-260504A: No Candidate Transients from the Zwicky Transient Facility
- EP260514a: GROWTH-India Telescope optical upper limit
- GRB 260511B: NOT optical observations
- Konus-Wind detection of GRB 260512A
- GRB 260510C: CALET Gamma-Ray Burst Monitor detection
- GRB 260511B: GMG Optical Upper Limit
- EP260514a: Global MASTER-Net observations report
- EP260514a: Einstein Probe detection of a fast X-ray transient
- EP260512a: LCO optical upper limits
- IPN triangulation of GRB 260512A
- GRB 260511B: Mephisto multi-band optical followup
- Fermi GRB 260514A: Global MASTER-Net observations report
- GRB 260512A: AstroSat CZTI detection
- The EP-WXT trigger 01709262077 is likely a flaring star
- EP260512a: EP-FXT follow-up observation
- EP260507a: Xinglong Schmidt optical counterpart detection
- GRB 260514A: Fermi GBM Final Real-time Localization
- EP260512a: Global MASTER-Net observations report
- Fermi GRB 260513A: Global MASTER-Net observations report
- Fermi GRB 260512A: Global MASTER-Net observations report
- GRB 260511B: further SAO RAS optical observations
- GRB 260513A: Fermi GBM Final Real-time Localization
- GRB 260509A: SVOM/VT optical observations
- Konus-Wind detection of GRB 260511B
- The EP-WXT trigger 01709262036 is likely a flaring star
- EP260512a: COLIBRÍ optical upper limits
- EP260512a: Einstein Probe detection of an X-ray transient
- GRB 260511B: further J-band observations by the SYSU 80 cm infrared telescope
- GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
- GRB 260512A: NuSTAR detection of prompt emission
- GRB 260509A: Infrared J and Hs observations with MDM/MIRAGE
- GRB 260510C: Infrared J and Hs detections with MDM/MIRAGE
- EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
- GRB 260512A: Fermi GBM Final Real-time Localization
- GRB 260511A: Glowbug gamma-ray detection
- Konus-Wind detection of GRB 260511A
- MASS-Cube (GRID 2.0) detection of GRB 260511A
- MASS-Cube (GRID 2.0) detection of GRB 260507A
- GRB 260511B: SAO RAS optical observations
- GRB 260510D: Glowbug gamma-ray detection of a likely short burst
- GRB 260511B: FRAM-ORM optical detection
- GRB 260511A: EP-FXT follow-up observation
- GRB 260511B: EP-FXT follow-up observation
- GRB 260511B: LCO optical counterpart detection
- GRB260511B: MAO/AZT-22 optical observations
- GRB 260511A: SVOM/VT optical observations
- GRB 260511B: LCO optical observations
- GRB 260511B: OHP/T193 spectroscopic observations
- GRB 260511B: GOTO optical counterpart detection
- GRB 260511B: Xinglong 2.16m/BEFOSC redshift confirmation
- GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
- GRB 260510A: AstroSat CZTI detection (Erroneous Submission)
- GRB 260511B: SVOM/VT optical observations
- GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
- GRB 260510B: EP-FXT follow-up observation
- GRB 260511B: OSIRIS+/GTC redshift z=2.006
- GRB 260510C: Fermi GBM Observation
- GRB 260509A: SAO RAS optical observations
- GRB 260511A: REM near-infrared detection
- GRB 260511B: GROWTH-India Telescope optical observations
- GRB 260511B: AstroSat CZTI detection
- GRB 260506B: Glowbug gamma-ray detection
- GRB 260506A: Glowbug gamma-ray detection of a short burst
- GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
- GRB 260511B: NuSTAR detection of prompt emission
- GRB 260511A: NuSTAR detection of prompt emission
- GRB 260511B: Fermi GBM Detection
- GRB 260511C: Fermi GBM Final Real-time Localization
- GRB 260511B: SVOM/VT optical observation with VHF data
- GRB 260511B: TRT optical observation
- GRB 260510B: SVOM/ECLAIRs refined analysis
- GRB 260511B : MITSuME Akeno optical afterglow candidate detection
- GRB 260511A: Fermi GBM Detection
- GRB 260511B SVOM/C-GFT optical counterpart detection
- EP260509a: LCO optical upper limits
- GRB 260511A: UTGO H50 optical afterglow observation
- GRB 260510C: AstroSat CZTI detection
- GRB 260511B: SVOM detection of a burst
- GRB 260511B: Fermi GBM Final Real-time Localization
- GRB 260510C: EP-FXT follow-up observation
- GRB 260510C: SVOM/VT optical counterpart confirmation
- EP260509a: EP-FXT non-detection and upper limit
- GRB 260511A: SVOM/VT optical observation with VHF data
- Fermi GRB 260511A: Global MASTER-Net observations report
- GRB 260511A: KAIT optical afterglow observations
- GRB 260511A: LCO optical afterglow detection
- GRB 260511A: SVOM/COLIBRÍ (FM-GFT) optical counterpart
- GRB 260511A: TRT optical counterpart detection
- GRB 260511A: SVOM detection of a bright burst
- GRB 260511A: BALROG localization (Fermi Trigger 800172815 / GRB 260511259)
- GRB 260510C: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate