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').
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 130816B: GROND afterglow candidate
- GRB 130816A: Swift-XRT refined Analysis
- GRB 130816A, Swift-BAT refined analysis
- GRB 130816A: Fermi GBM observation
- GRB 130816B: Swift-XRT refined Analysis
- GRB 130816B: Enhanced Swift-XRT position
- GRB 130816A: GROND confirmation of afterglow
- GRB 130816A: Enhanced Swift-XRT position
- GRB 130816B: Swift detection of a burst
- GRB 130816A: REM NIR candidate afterglow
- GRB 130816A: Swift detection of a burst
- Refined IPN Triangulation of GRB 130812B
- Konus-Wind observation of GRB 130812B
- IPN Triangulation of GRB 130812B (long/soft)
- GRB 130812A: Swift/UVOT Upper Limits
- GRB 130812A, Swift-BAT refined analysis
- GRB 130812A: GROND upper limits
- GRB 130812A: Swift-XRT refined Analysis
- GRB 130812A: Enhanced Swift-XRT position
- GRB 130812A: Swift detection of a burst
- Correction to GCN Circ. 15086 "GRB130807A: Swift/UVOT observations"
- GRB130807A: Swift/UVOT observations
- GRB 130807A: Swift-XRT refined analysis
- GRB 130806A: Swift/UVOT Upper Limits
- GRB 130807A, Swift-BAT refined analysis
- GRB 130807A: Swift detection of a GRB or Galactic transient
- Konus-Wind observation of GRB 130804A
- GRB 130623A: GROND detection of the optical/NIR afterglow
- GRB 130806A: MITSuME Akeno Optical observation
- GRB 130806A: Swift-XRT refined Analysis
- GRB 130806A: MITSuME Okayama upper limits
- GRB 130806A, Swift-BAT refined analysis
- IPN localization of GRB 130804A
- SGR 1745-29 (Swift trigger 565443), Swift-BAT refined analysis
- GRB130803A: GROND observations
- GRB 130806A: Enhanced Swift-XRT position
- GRB 130806A: Swift detection of a burst
- GRB 130804A; Fermi GBM observation
- Trigger 565443: Swift detection of a burst from SGR J1745-29
- GRB 130803A: Swift-XRT refined Analysis
- GRB 130803A: RATIR Optical and NIR Observations
- GRB130803A: GROND detection of possible host
- GRB 130803A: Swift/UVOT Upper Limits
- GRB 130803A; Fermi GBM observation
- GRB 130803A, Swift-BAT refined analysis
- GRB 130803A: Enhanced Swift-XRT position
- GRB 130803A: Faulkes Telescope South Observations
- GRB 130603B: Second epoch of HST WFC/F160W imaging
- GRB 130803A: Swift detection of a burst
- GRB 130727A: Watcher optical limit
- GRB 130722A: RATIR Optical Observations
- GRB 130727A: Swift/UVOT Detection
- Konus-Wind observation of GRB 130727A
- GRB 130727A: Swift-XRT refined Analysis
- GRB 130727A: Fermi GBM detection
- GRB 130727A: GROND observations
- GRB 130727A: Enhanced Swift-XRT position
- GRB 130727A: Faulkes Telescope South optical afterglow
- GRB 130727A: Swift-BAT refined analysis
- GRB 130727A: Swift-XRT observations
- GRB 130727A: Swift-XRT and Swift-UVOT prompt observations
- GRB 130727A: Swift detection of a burst
- GRB 130725B: Swift/UVOT Observations
- GRB 130725B: Swift trigger time correction
- Fermi Gamma-ray Burst Monitor trigger 396484884 / 130725945 is not a GRB
- GRB 130725A: Swift-XRT refined Analysis
- GRB 130725B, Swift-BAT refined analysis
- GRB 130725B: Swift-XRT refined Analysis
- GRB130725B: REM-ROS2 optical observations
- GRB 130725B - UVOT-enhanced XRT position
- Fermi Gamma-ray Burst Monitor trigger 396533554 / 130726509 is not a GRB
- GRB 130725A: Swift/UVOT Upper Limits
- GRB 130725A - Faulkes Telescope South Observations
- GRB 130725B: GROND Detection of the Optical/NIR Afterglow
- GRB 130725A: MITSuME Ishigakijima Optical Observation
- GRB 130725B: Swift/UVOT Detection of an Optical Counterpart
- GRB 130725A, Swift-BAT refined analysis
- GRB 130719A: Skynet/PROMPT observations
- GRB 130725B: Swift detection of a burst
- Swift Trigger 563980 is GRB 130725A
- Fermi Gamma-ray Burst Monitor trigger 396447899 / 130725517 is not a GRB
- Swift Trigger 563980 cannot be identified at this time.
- GRB 130702A in the Ep,i - Eiso plane
- Retraction of GCN Circ. 15020 (GRB 130722C Tiled Swift observations)
- Konus-Wind observation of GRB 130722A
- GRB 130722A: Swift/UVOT Detection
- GRB 130722A: MITSuME Okayama upper limits
- GRB 130722C Tiled Swift observations
- GRB 130722A: Enhanced Swift-XRT position
- GRB 130722A: Swift-XRT refined Analysis
- GRB 130722A: Skynet/GORT observations
- GRB 130719A, Swift-BAT refined analysis
- GRB 130722A: Faulkes Telescope South optical candidate
- GRB 130715A: Suzaku WAM observation of the prompt emission
- GRB 130722A: Swift detection of a burst
- GRB 130719A: Swift detection of a burst
- GRB 130716A: Fermi GBM observation
- GRB 130716A Swift-BAT Spectral lag analysis
- GRB 130702A : Xinglong TNT continue optical observation
- GRB 130716A: Gemini-North imaging