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"19590 results found.
- GRB 090520B: Fermi GBM detection
- GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 090518: Fermi GBM detection
- GRB 090520 Swift-BAT detection of a burst in ground analysis
- GRB 090423: Fermi GBM T90 follow-up analysis results
- GRB 090516: Fermi GBM observation
- GRB 090519: Swift-XRT refined analysis
- GRB 090519: GROND observation
- GRB 090519: Swift/UVOT Upper Limits
- GRB 090519, Swift-BAT refined analysis
- GRB 090519: Enhanced Swift-XRT position
- GRB 090519: FARO Chante Perdrix Observatory optical observations
- GRB 090519: TAROT Calern observatory optical observations
- GRB 090519: Swift detection of a burst
- GRB 090518: Swift/UVOT Upper Limits
- GRB 090518, Swift-BAT refined analysis
- GRB 090516, RIMOTS optical upper limits
- GRB090518 : Optical upper limit by MOA-II telescope
- GRB 090518: Swift-XRT refined analysis
- GRB 090518: Enhanced Swift-XRT position
- GRB 090518: Swift detection of a burst
- GRB 090515: Swift/BAT spectral lag results
- GRB 090516: Swift-BAT refined analysis
- GRB 090516: GROND OBSERVATIONS
- GRB 090516 - Zadko Telescope observations
- GRB 090516: Swift XRT refined analysis
- GRB 090516: Swift/UVOT Observations
- GRB 090516: Enhanced Swift-XRT position
- GRB 090516: Faulkes Telescope South optical afterglow
- GRB 090516: Swift detection of a burst
- GRB 090515: ROVOR Upper Limit
- GRB 090515: MMT/MMIRS NIR Upper Limit
- GRB 090515: Swift/UVOT Observations
- GRB 090515: Swift-XRT refined analysis
- GRB 090515: Enhanced Swift-XRT position
- GRB 090509: Fermi GBM observation
- GRB 090515: Swift-BAT refined spectral analysis
- GRB 090515: Swift-BAT refined analysis
- GRB 090509 - Zadko Telescope observations
- GRB 090515: Super-LOTIS Upper Limits
- GRB 090515: PAIRITEL Upper Limits
- GRB 090515: KAIT optical upper limits
- GRB 090515: ROTSE-III Optical Limits
- GRB 090515: Swift detection of a short burst
- GRB 090510: Suzaku WAM observation of the prompt emission
- GRB090510: VLT/FORS2 spectroscopic redshift
- GRB 090510: GROND observations
- GRB 090510: Swift/UVOT host galaxy candidates
- GRB 090510: Fermi-LAT follow-up analysis
- GRB 090509, further Swift-BAT refined analysis
- Konus-Wind observation of GRB 090510
- GRB 090510: UVOT refined analysis
- GRB 090510: Swift XRT refined analysis
- GRB 090510: Enhanced Swift-XRT position
- GRB 090510: NOT afterglow confirmation
- GRB 090510: Swift-BAT refined analysis
- GRB 090510: Fermi GBM detection
- GRB 090509: Swift-BAT refined analysis
- Fermi LAT detection of GRB 090510
- GRB 090510: Swift/UVOT Detection of a Candidate Optical Afterglow
- GRB 090510: Swift detection of a short hard burst
- GRB 090408: optical upper limit
- GRB 090418A: optical observation
- GRB 090509: GROND afterglow candidate
- GRB 090509: Swift detection of a burst
- GRB 090423: optical limit
- GRB 090424: optical observations
- GRB 090429A: ROVOR magnitude limit
- GRB 090426: optical observations
- GRB 090429D: Fermi GBM detection
- GRB 090429B: Swift/UVOT Upper Limits
- GRB 090429A: Swift/UVOT Upper Limits
- GRB 090429A: Swift-XRT refined analysis
- GRB 090429A: GROND upper limits
- GRB 090429B: Swift XRT refined analysis
- GRB 090429A: Enhanced Swift-XRT position
- GRB 090429B: RIMOTS optical upper limits
- GRB 090429B: Swift-BAT refined analysis
- GRB 090429A: Swift-BAT refined analysis
- GRB 090429B: Enhanced Swift-XRT position
- GRB 090429A - Correction to XRT position
- GRB090429B: Gemini-N infrared IR candidate
- GRB 090429B: GROND Observations
- GRB 090429B: Swift detection of a burst
- GRB 090429: Swift detection of a burst
- GRB 090424 : Multiband Optical observation from Nainital
- GRB 090423: CARMA mm observations
- GRB 090423: millimeter detection
- GRB 090426: Swift/BAT spectral lag results
- GRB 090424: Suzaku WAM observation of the prompt emission
- GRB 090426: GROND Observations of the Optical/NIR Afterglow
- GRB090426 Swift/UVOT observations
- GRB 090426: Swift-BAT refined analysis
- GRB 090426: Swift-XRT refined analysis
- GRB 090423: GROND second epoch imaging and refined SED
- GRB 090426: Enhanced Swift-XRT position
- GRB 090426, RIMOTS optical upper limits
- GRB 090426: TNT confimation of optical counterpart
- GRB 090426: Swift detection of a burst with an optical counterpart
- GRB 090424: MASTER-Net prompt optical limit