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.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"23572 results found.
- GRB 090625B: Faulkes Telescope South observations
- GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
- GRB 090625B: a long GRB localized by INTEGRAL
- GRB 090625: Fermi GBM detection
- GRB 090618: Correction to GCN 9568
- GRB 090617: Suzaku WAM observation of the prompt emission
- GRB 090618: Suzaku WAM observation of the prompt emission
- GRB 090623: Fermi GBM detection
- GRB 090621B: I-band observations from 1.23m CAHA
- GRB 090621D: Fermi GBM detection
- GRB 090621B: Gemini spectrum of afterglow candidate
- GRB 090621C: Fermi GBM detection
- GRB 090621B: P60 Observations
- GRB 090620: Fermi GBM detecion
- Konus-Wind and Konus-RF observations of GRB 090618
- GRB 090621B: Swift-BAT refined analysis
- GRB 090621B: RTT150 optical observations
- GRB 090618: RTT150 optical observations
- GRB 090621A: Swift-BAT refined analysis
- GRB 090621B: Swift detection of a short hard burst
- GRB090618: Spectrum and photometry from 6.0m BTA
- GRB 090618: BOAO V-band Observation
- GRB 090621: Swift detection of a burst
- GRB 090618: Swift-BAT refined analysis
- GRB090618: Swift-XRT team refined analysis
- GRB 090618: AGILE observations
- GRB 090618: LOAO R-band Observation
- GRB 090618: Lick/KAST Spectroscopy
- GRB 090618: Swift detection of a bright burst with optical afterglow
- GRB 090612: Fermi GBM detection
- SGR 0418+5729 Fermi/GBM Detection of Pulsations
- GRB 090602: Suzaku WAM observation of the prompt emission
- RXTE Discovery of Pulsations from SGR 0418+5729
- Konus-RF observation of SGR burst 090605A
- Discovery of a new soft gamma repeater source, SGR 0418+5729
- GRB 090608: Fermi GBM detection
- GRB 090607: Swift-BAT refined analysis of the SHB
- GRB 090607: Faulkes Telescope North observations
- GRB 090607: Swift detection of a burst
- GRB 090530B: Suzaku WAM observation of the prompt emission
- GRB 090530: RTT150 Optical Observation
- GRB 090529A: RTT150 Optical Observations
- GRB 090528: Suzaku WAM observation of the prompt emission
- GRB 090528B: Suzaku WAM observation of the prompt emission
- GRB090529B: ROVOR Upper Limits
- GRB 090531B: Swift/BAT spectral lag results
- GRB 090529C: Fermi GBM detection
- GRB 090529B: Fermi GBM detection
- GRB 090531B, RIMOTS optical upper limits
- GRB 090529: MITSuME optical observation
- GRB 090531B: Swift-BAT refined analysis
- GRB 090531B: Swift detection of a burst
- GRB 090531: Swift-BAT refined analysis
- GRB090530: R-band Observation
- GRB 090531: Swift detection of a burst
- GRB 090529: NOT optical observations
- GRB 090530: Swift-BAT refined analysis
- GRB 090530: GRAS002 refined OA analysis
- GRB 090530: PAIRITEL NIR Detections
- GRB 090530: Swift detection of a burst with an optical counterpart
- GRB 090529: optical observations
- GRB 090529: TLS Afterglow Observations
- GRB 090529: Swift-BAT refined analysis
- GRB 090529: Swift detection of a burst
- GRB 090520D: Fermi GBM detection
- GRB 090520C: Fermi GBM detection
- GRB 090520B: Fermi GBM detection
- GRB 090522 : Fermi GBM detection
- GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 090513B: Fermi GBM detection
- GRB 090518: Fermi GBM detection
- GRB 090516C: Fermi GBM detection
- GRB 090520 Swift-BAT detection of a burst in ground analysis
- GRB 090516B: Fermi GBM detection
- GRB 090519: Swift-XRT refined analysis
- GRB 090519: GROND observation
- GRB 090519: Swift/UVOT Upper Limits
- GRB 090519, Swift-BAT refined analysis
- GRB 090519: TAROT Calern observatory optical observations
- GRB 090519: Swift detection of a burst
- GRB 090511: Fermi GBM Detection
- GRB 090514: Fermi GBM detection
- GRB 090518, Swift-BAT refined analysis
- GRB 090516, RIMOTS optical upper limits
- GRB090513: Fermi GBM detection
- GRB 090518: Swift detection of a burst
- GRB 090516: Swift-BAT refined analysis
- GRB 090516 - Zadko Telescope observations
- GRB 090516: Swift/UVOT Observations
- GRB 090516: Faulkes Telescope South optical afterglow
- GRB 090516: Swift detection of a burst
- GRB 090515: Lick Upper Limits
- GRB 090515: MMT/MMIRS NIR Upper Limit
- GRB 090515: Swift/UVOT Observations
- GRB 090515: Swift-BAT refined analysis
- GRB 090509 - Zadko Telescope observations
- GRB 090515: Gemini-N upper limit
- GRB 090515: Super-LOTIS Upper Limits
- GRB 090515: PAIRITEL Upper Limits
- GRB 090515: Swift detection of a short burst