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.
Lucene Examples (click to copy):
subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
32080 results found.
- GRB 231129A: VZLUSAT-2 detection
- GRB 231129B: Swift-XRT observations
- GRB 231128A: VZLUSAT-2 detection
- GRB 231129C: AGILE detection
- GRB 231129A : MITSuME Akeno optical upper limits
- GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
- GRB 231129A: Swift-BAT refined analysis
- GRB 231129C: MASTER OT detection
- GRB 231129A: BOOTES-5/JGT optical upper limit
- GRB 231129C: Fermi-LAT detection
- GRB 231129A: JinShan optical upper limit
- GRB 231129C: GRBAlpha detection
- GRB 231129C: Glowbug gamma-ray detection
- GRB 231129C: Swift-XRT observations
- GRB 231129A: Swift/UVOT Upper Limits
- GRB 231129A: optical upper limit in Mondy observatory
- GRB 231129C: GECAM-B detection of a bright burst
- GRB 231129C: AstroSat CZTI detection
- GRB 231129C: iTelescope OT retraction
- GRB 231129C: CALET Gamma-Ray Burst Monitor detection
- GRB 231129C: Fermi GBM Observation of a very bright GRB
- GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
- GRB 231129C: Tiled Swift observations
- GRB 231127A: GRBAlpha detection
- GRB 231129C: MAXI/GSC detection
- GRB 231129C: BALROG localization (Fermi Trigger / GRB 231129799)
- GRB 231129C: Fermi GBM detection of a very bright burst
- GRB 231129A: Enhanced Swift-XRT position
- GRB 231129A: Swift-XRT refined Analysis
- GRB 231129C: Fermi GBM Final Real-time Localization
- GRB 231129B: Tiled Swift observations
- GRB 231129B: MAXI/GSC detection
- GRB 231129A: GECAM-C detection of a long burst
- GRB 231129A: INTEGRAL detection of a long GRB
- GRB 231129A: Swift detection of a burst
- GRB 231128A: Fermi GBM Final Real-time Localization
- GRB 231123C: Fermi GBM Observation
- GRB 231123B: Fermi GBM Observation
- 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 231127A: AstroSat CZTI detection
- GRB 231125A (short): Glowbug gamma-ray detection
- GRB 231123B: Swift/BAT-GUANO detection of a burst outside the coded FOV
- GRB 231124A: GRBAlpha detection
- GRB 231125A: AstroSat CZTI detection of a short burst
- GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
- GRB 231126A: Fermi GBM Final Real-time Localization
- GRB 231123C: Insight-HXMT/HE detection
- GRB 231123C (short): Glowbug gamma-ray detection
- GRB 231124A: Glowbug gamma-ray detection
- GRB 231123C: Swift/BAT-GUANO detection of a short burst likely outside the coded FOV
- GRB 231124A: CALET Gamma-Ray Burst Monitor detection
- GRB 231115A: XMM-Newton observation
- GRB 231124A: Fermi GBM Final Real-time Localization
- GRB 231123A: AstroSat CZTI detection
- GRB 231117A: Mondy optical observations
- GRB 231123C: Fermi GBM Final Real-time Localization
- GRB 231123B: Fermi GBM Final Real-time Localization
- GRB 231118A: REM optical afterglow detection
- GRB 231122B: AstroSat CZTI detection
- GRB 231122B: CALET Gamma-Ray Burst Monitor detection
- GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
- GRB 231117A: Chandra afterglow detection
- GRB 231123A: Fermi GBM Final Real-time Localization
- GRB 231122B: Glowbug gamma-ray detection
- GRB 231117A: Continued GTC Observations
- GRB 231122A: GECAM detection
- GRB 231122B: GECAM detection
- GRB 231122A: Fermi GBM Final Real-time Localization
- GRB 231118A: ATCA detection of radio counterpart
- GRB 231117A: Swift/UVOT late time observations
- GRB 231117A: GTC Near-Infrared Observations
- GRB 231117A: Swift-BAT refined analysis
- GRB 231118A: GRBAlpha detection
- LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
- GRB 231118A: VZLUSAT-2 detection
- GRB 231117A: AMI-LA radio observations
- GRB 231118A: Swift-BAT refined analysis
- Konus-Wind detection of GRB 231020A
- GRB 231117A: LDT Confirmation of Optical Fading
- GRB 231117A: Wendelstein Confirmation of Fading of the Optical Afterglow
- GRB 231118B: CALET Gamma-Ray Burst Monitor detection
- GRB 231117A: CALET Gamma-Ray Burst Monitor detection
- 231118A: Swift-UVOT Detection
- GRB231117A: Swift-UVOT detection
- GRB 231117A : MITSuME Akeno optical afterglow candidate detection
- GRB 231118B: Fermi GBM observation
- GRB 231118A: Fermi GBM observation
- GRB 231120A: Fermi GBM Final Real-time Localization
- 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