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"19534 results found.
- GRB 140916A: Swift-XRT refined Analysis
- GRB 140916A: Enhanced Swift-XRT position
- GRB 140916A: FTS observations
- GRB 140916A: Prompt enhanced Swift-XRT position
- GRB 140916A: Swift detection of a burst
- GRB 140907A: Continued DCT Observations
- GRB 140909A: Confirmation of the Swift-XRT afterglow
- GRB 140907A: Mondy optical observations
- GRB 140909A: Swift/UVOT Upper Limits
- GRB 140909A: Swift-XRT observations
- GRB 140907A: TShAO observations
- GRB 140909A: Swift detection of a GRB
- GRB 140907A: MASTER optical observations
- Refined IPN Triangulation of GRB 140906C
- IPN Triangulation of GRB 140906C (short/hard)
- GRB 140907A: T100 observations
- GRB 140907A: Swift-BAT refined analysis
- GRB 140907A: Fermi GBM Detection
- GRB 140907A: Swift-XRT refined Analysis
- GRB 140907A: Enhanced Swift-XRT position
- GRB140907A: Swift UVOT detection
- GRB 140907A: Swift detection of a burst with an optical counterpart
- GRB 140903A: Confirmation of Optical Fading from Discovery Channel Telescope
- GRB 140901B: Swift XRT observation
- GRB 140903A: FTN observations
- GRB 140818B: TShAO optical upper limit
- GRB 140903A: MAXI/GSC upper limit
- GRB 140901B: Fermi GBM detection
- GRB 140901B found in ground analysis of BAT data
- GRB 140903A: Swift/UVOT Upper Limits
- GRB 140903A: Swift-BAT Spectral lag analysis
- GRB 140903A: P60 Optical Observations
- GRB140903A: Discovery Channel Telescope Optical Detection
- GRB 140903A: Swift-BAT refined analysis
- GRB 140903A: Swift-XRT refined Analysis
- GRB 140903A: Confirmed Swift detection of a short burst
- GRB 140903A: Preliminary Swift/XRT localization
- GRB 140903A: Swift detection of a possible burst
- GRB 140831A: iPTF observations of a possible short burst detected by Fermi GBM
- GRB 140828A, Swift-BAT refined analysis
- GRB 140828A: Fermi GBM observation
- Swift Mission Operations Center Fully Operational
- IPN Triangulation of GRB 140825A (very intense/long)
- GRB 140828A: Swift detection of a burst
- Swift Burst Response Reenabled
- GRB 140818B: TLS observations
- GRB 140824A: optical upper limit in CrAO
- GRB 140824B: Swift observations
- Swift Mission Operations Center Moving Tomorrow
- GRB 140824A: Swift-XRT refined Analysis
- GRB 140824A: Swift-BAT refined analysis
- GRB 140824A: Enhanced Swift-XRT position
- GRB 140824A: Swift/UVOT Upper Limits
- GRB 140824A: Swift detection of a burst
- Fermi trigger 430148973: Swift-XRT observation
- GRB 140818A: GROND confirmation of afterglow candidate
- GRB 140818B, Swift-BAT refined analysis
- GRB 140818B: Swift/UVOT Upper Limits
- GRB 140818B: Swift-XRT refined Analysis
- GRB 140818B: Fermi GBM detection
- GRB140818B : GROND afterglow candidate
- GRB 140818B: Enhanced Swift-XRT position
- GRB 140818B: OSN I-band afterglow candidate
- GRB 140817A: Swift/UVOT Afterglow Detection
- GRB 140818B: Swift detection of a burst
- GRB 140818A - Fermi GBM Detection
- Swift detection of SAX J1712.6-3739
- GRB 140818A: Swift-XRT and UVOT potential afterglow detection
- Konus-Wind observation of GRB 140817A
- GRB 140818A Tiled Swift observations
- GRB 140817A: Swift-XRT refined Analysis
- GRB 140817A: Fermi GBM Detection
- GRB 140817A: Swift-BAT refined analysis
- GRB 140817A draft circular on nearby galaxy
- GRB 140817A: Enhanced Swift-XRT position
- GRB 140817A: Swift-XRT position
- GRB 140817A: Swift detection of a burst
- Swift Trigger 609694 is probably not an astrophysical source
- GRB 140815A: Swift-XRT observations
- GRB 140814A: Swift-XRT and UVOT observations
- GRB 140814A: Swift-XRT and UVOT observations
- Swift Mission Operations Center Moving
- GRB 140808A: Confirmation of the Swift-XRT afterglow
- GRB140810A: Fermi-LAT detection
- Swift trigger 609139 is probably 4U 1850-03
- Swift observations of possible GRB 140809A candidate
- GRB 140808A: Swift/UVOT Upper Limits
- GRB 140808A: Swift-XRT observations
- GRB 140808A: optical afterglow candidate iPTF14eag
- GRB140801A: Swift/XRT further observations
- GRB 140730A: GROND Upper limits
- GRB 140801A: Swift/UVOT Upper Limits
- GRB 140801A: Swift-XRT observations
- GRB 140730A, Swift-BAT refined analysis
- GRB 140709B: TShAO optical upper limit
- Swift Trigger 607945: possible noise event in the direction of NGC2559
- GRB 140730A: LCO-Sutherland observations
- GRB 140730A: Swift-XRT refined Analysis
- GRB 140730A: Swift/UVOT Upper Limits
- GRB 140730A: Enhanced Swift-XRT position