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').
14272 results found.
- GRB 231129A: JinShan optical upper limit
- GRB 231129C: Glowbug gamma-ray detection
- GRB 231129A: Swift/UVOT Upper Limits
- GRB 231129A: optical upper limit in Mondy observatory
- GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
- GRB 231129A: Enhanced Swift-XRT position
- Fermi-LAT gamma-ray observations of IceCube-231125A
- Integral GRB231129.21: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231129ac: Identification of a GW compact binary merger candidate
- GRB 231129A: Swift detection of a burst
- GRB 231117A: MeerKAT 1.3GHz detection
- GRB 231125A (short): Glowbug gamma-ray detection
- GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
- GRB 231123C (short): Glowbug gamma-ray detection
- GRB 231124A: Glowbug gamma-ray detection
- GRB230728A: VIRT optical upper limit
- GRB230506C: VIRT optical upper limit
- GRB230506B: VIRT optical upper limit
- GRB 231117A: Mondy optical observations
- GRB 231118A: REM optical afterglow detection
- GRB 231122B: Glowbug gamma-ray detection
- GRB 231117A: Continued GTC Observations
- GRB 231118A: ATCA detection of radio counterpart
- GRB 231117A: Swift/UVOT late time observations
- GRB 231117A: GTC Near-Infrared Observations
- GRB 231117A: AMI-LA radio observations
- Konus-Wind detection of GRB 231020A
- 231118A: Swift-UVOT Detection
- GRB231117A: Swift-UVOT detection
- GRB 231117A : MITSuME Akeno optical afterglow candidate detection
- GRB 231117A: Swift-XRT refined Analysis
- GRB 231118A: Swift-XRT refined Analysis
- GRB 231118A: MeerLICHT afterglow detection
- GRB 231117A: OHP/T120 optical observations
- GRB 231118A: VLT/X-shooter redshift
- GRB 231117A: Pan-STARRS1 follow-up confirms rapid fading
- GRB 231117A: AKO Follow-Up Observation
- GRB 231118A: AstroSat CZTI detection
- GRB 231117A: 10 GHz VLA detection
- GRB 231118A: Las Cumbres optical detection
- GRB 231118A: LCOGT Optical Observations
- GRB 231118A: Enhanced Swift-XRT position
- GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
- GRB 231118A: Skynet Optical Afterglow Discovery
- GRB 231115A: Wendelstein Optical/Infrared Observations
- GRB 231115A: JinShan optical upper limits
- GRB 231117A: GIT optical follow-up
- GRB 231117A: LT observations consistent with fading
- GRB 231117A: REM optical and NIR early-time observations
- GRB 231117A: AKO Optical Upper Limit
- GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
- GRB 231117A (short): Glowbug gamma-ray detection
- GRB 231117A: ATLAS non-detection of an optical counterpart
- GRB 231115A : OHP/T120 optical upper limit
- GRB 231117A : MITSuME Akeno optical upper limits
- GRB 231117A: Enhanced Swift-XRT position
- GRB 231117A: Swift detection of a bright short burst
- GRB 231115A: Non-detection of radio emission with CHIME/FRB
- GRB 231111A: Swift/UVOT Detection
- GRB 231115A: Swift-XRT and Swift-UVOT observations
- Konus-Wind detection of GRB 231115A (a probable Magnetar Giant Flare from M82)
- GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
- GRB 231115A : MITSuME Akeno and Okayama optical upper limits
- GRB 231115A: Gaoyazi/GOT follow-up and archival observations
- GRB 231115A / AT2023xvj: Updated GIT analysis
- GRB 231115A: Kinder observations with Lulin observatory
- GRB231115A: GRANDMA Observations
- GRB 231115A: GOTO pre-burst limits of AT2023xvj
- GRB 231115A: pre-burst ZTF upper limits for GRB optical counterpart candidate
- GRB 231115A (short): Glowbug gamma-ray detection
- GRB 231115A: archival HST observations
- GRB 231115A: GROWTH-India discovery of a potential optical counterpart
- GRB 231113A (short): Glowbug gamma-ray detection
- GRB 231114A (short): Glowbug gamma-ray detection
- LIGO/Virgo/KAGRA S231113bw: GROWTH-India coverage and upper limits
- GRB 231106A: Glowbug gamma-ray detection
- GRB 231111A: Xinglong-2.16m optical observations
- GRB 231110A: Glowbug gamma-ray detection
- GRB 231111A: Leavitt Observatory optical observations
- GRB231111A: Optical follow-up observations with Mephisto
- GRB 231111A: GMG observation (correction)
- GRB 231111A: GMG observation upper limit
- GRB 231110A: Terskol Zeiss-2000 optical upper limit
- GRB 231111A: Mondy optical observations
- GRB 231111A: Enhanced Swift-XRT position
- GRB 231110A: SAO RAS optical observations
- GRB231111A: GIT confirmation of the optical afterglow
- GRB 231111A: Nanshan/HMT optical observations
- GRB 231111A: Swift detection of a burst with an optical counterpart
- GRB231110A: WFST Observation and upper limits
- GRB 231109A: Fermi GBM Final Localization
- GRB 231104A: 3.6m DOT optical upper limit
- GRB 231104A: NOT upper limit
- GRB 231104A: AKO Upper Limit
- GRB 231104A: Swift-XRT refined Analysis
- GRB 231104A: Swift/UVOT Upper Limits
- GRB 231104A: Enhanced Swift-XRT position
- GRB231104A: LCOGT Optical Upper Limits
- GRB 231104A: Swift detection of a bright burst
- Fermi-LAT gamma-ray observations of IceCube-231027A