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.
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').
10044 results found.
- GRB 240122B: CALET Gamma-Ray Burst Monitor detection
- GRB 240123A: Mondy continued optical observations and the PL decay index
- GRB 240123A : MITSuME Akeno optical afterglow candidate detection
- Fermi GBM Sub-Threshold Detection of GRB 240123A
- GRB 240123A: Mondy continued optical observations + correction of the GRB name in GCN 35605
- GRB 240123A: Mondy optical afterglow observations
- GRB 240122A: Redshift from OSIRIS+/GTC
- GRB 240122A: MAXI/GSC detection
- GRB 240118A: Mondy optical observations
- GRB 240117A: CALET Gamma-Ray Burst Monitor detection
- GRB 240118A: GRBAlpha detection
- GRB 240118A: AbAO optical upper limit
- GRB 240112C: VZLUSAT-2 detection
- GRB 240107A: VZLUSAT-2 detection
- GRB 240112C: GRBAlpha detection
- GRB 240114A: MAXI/GSC detection
- GRB 240112C: Swift/UVOT Detection
- GRB 231215A: radio detection with the VLA
- GRB 230818A: further radio observations with the VLA
- GRB 230812B: further radio observations with the VLA
- GRB 240106A: GRBAlpha detection
- GRB 240107A: MAXI/GSC detection
- GRB 231220A: Swift-UVOT upper limit
- GRB 240101A: Terskol Zeiss-2000 optical observations
- GRB 240101C: GRBAlpha detection
- GRB 240101B: Swift/UVOT Upper Limits
- GRB 240101A: Swift/UVOT Upper Limits
- GRB 231230A: Swift/UVOT Upper Limits
- GRB 231222B: GRBAlpha detection
- GRB 231222B: Fermi-LAT detection
- IceCube-231211A: GRANDMA observations of PKS2047+098
- GRB 231216A: Swift/UVOT Upper Limits
- GRB 231216A: NOT optical upper limits
- GRB 231215A: GRBAlpha detection
- GRB 231215A: NOT optical observations
- GRB 231215A: Redshift from OSIRIS+ / GTC
- GRB 231205B: VZLUSAT-2 detection
- GRB 231204A: VZLUSAT-2 detection
- GRB 231215A: CALET Gamma-Ray Burst Monitor detection
- GRB 231215A: Swift/UVOT Detection
- GRB 231215A: AGILE detection
- GRB 231215A: GROWTH-India optical follow-up
- GRB 231215A : MITSuME Akeno optical afterglow candidate detection
- GRB 231215A: Mondy optical bright afterglow detection
- GRB 231214A: Fermi-LAT detection
- GRB 231208A: GRBAlpha detection
- GRB 231205B: optical upper limit in TSHAOand AbAO
- GRB 231205B: AGILE detection
- GRB 231129C: ASIM MXGS observation and localization
- GRB 231205B : MITSuME Akeno optical upper limits
- GRB 231204A: CALET Gamma-Ray Burst Monitor detection
- GRB 231205B: Swift detection of a burst
- GRB 231129A: VZLUSAT-2 detection
- GRB 231128A: VZLUSAT-2 detection
- GRB 231129C: AGILE detection
- GRB 231129A : MITSuME Akeno optical upper limits
- GRB 231129C: Fermi-LAT detection
- GRB 231129C: GRBAlpha detection
- GRB 231129A: optical upper limit in Mondy observatory
- GRB 231129C: CALET Gamma-Ray Burst Monitor detection
- GRB 231127A: GRBAlpha detection
- GRB 231129C: MAXI/GSC detection
- GRB 231129B: MAXI/GSC detection
- GRB 231129A: Swift detection of a burst
- GRB 231117A: MeerKAT 1.3GHz detection
- GRB 231127A: CALET Gamma-Ray Burst Monitor detection
- GRB 231125A: GRBAlpha detection
- GRB 231125A: CALET Gamma-Ray Burst Monitor detection
- GRB 231124A: GRBAlpha detection
- GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
- GRB230728A: VIRT optical upper limit
- GRB230506C: VIRT optical upper limit
- GRB230506B: VIRT optical upper limit
- GRB 231124A: CALET Gamma-Ray Burst Monitor detection
- GRB 231117A: Mondy optical observations
- GRB 231122B: CALET Gamma-Ray Burst Monitor detection
- GRB 231117A: Swift/UVOT late time observations
- GRB 231118A: GRBAlpha detection
- GRB 231118A: VZLUSAT-2 detection
- GRB 231117A: LDT Confirmation of Optical Fading
- GRB 231118B: CALET Gamma-Ray Burst Monitor detection
- GRB 231117A: CALET Gamma-Ray Burst Monitor detection
- GRB 231117A : MITSuME Akeno optical afterglow candidate detection
- LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
- GRB 231118A: VLT/X-shooter redshift
- GRB 231117A: AKO Follow-Up Observation
- GRB 231115A: Upper limit from CALET Gamma-Ray Burst Monitor
- GRB 231118A: Las Cumbres optical detection
- GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
- GRB 231117A: Lowell Discovery Telescope Observations
- GRB 231117A: ePESSTO+ host galaxy redshift confirmation
- GRB 231117A: GRBAlpha detection
- GRB 231117A: Keck spectroscopy of afterglow candidate
- GRB231117A: AGILE/MCAL analysis
- GRB 231117A: AKO Optical Upper Limit
- GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
- GRB 231117A: ATLAS non-detection of an optical counterpart
- GRB 231117A : MITSuME Akeno optical upper limits
- GRB 231117A: AGILE detection of a bright short burst
- GRB 231117A: Swift detection of a bright short burst