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"27034 results found.
- 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: Faulkes Telescope South Observations
- 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: 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
- 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 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.
- Konus-Wind observation of GRB 130722A
- GRB 130722A: Swift/UVOT Detection
- 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: UVOT Upper Limits
- GRB 130716A: Probable short-hard burst with delayed Swift data
- GRB 130715A: Fermi GBM detection
- GRB 130626A: Retraction of possible X-ray afterglow
- GRB 130708A: Swift XRT and UVOT Observations
- GRB 130702A: TNG spectroscopic observations of the emerging supernova
- GRB 130708A: Fermi GBM observation
- GRB 130702A: P200 Spectroscopic Confirmation of Associated Supernova
- GRB 130708A found in ground analysis of Swift-BAT data
- GRB 130628A: Suzaku WAM observation of the prompt emission
- GRB 130702A: Continued RATIR Optical and NIR Observations
- GRB 130702A: VLA detection
- GRB 130702A: further TNG observations
- GRB 130702A: further Swift-XRT observations
- GRB 130702A: Continued P60 observations
- GRB 130702A: RATIR Optical and NIR Observations
- GRB 130702A: CARMA 3mm detection
- GRB 130702A: NOT optical observations
- GRB 130702A: TNG optical observations
- GRB 130702A / Fermi394416326 : Nanshan optical observations
- Fermi GRB 130702A: Swift XRT and UVOT observations
- GRB 130702A / Fermi394416326: Fermi GBM detection
- GRB 130702A / Fermi394416326 : Fermi-LAT detection of a burst
- Fermi GBM trigger 394416326: MASTER early optical limit
- GRB 130628A: Fermi GBM detection
- Fermi394416326: iPTF detection of a possible optical afterglow
- Fermi GBM trigger 394325281 / 130630950 is not a GRB
- GRB 130701B: Fermi GBM detection
- GRB 130701A: Swift-XRT refined Analysis
- GRB 130701A: P60 Observations
- GRB 130701A, Swift-BAT refined analysis
- Konus-Wind observation of GRB 130701A
- GRB 130701A: Swift/UVOT Detection
- GRB 130701A: Swift detection of a burst
- GRB 130627B, Swift-BAT refined analysis
- GRB 130627A, Swift-BAT refined analysis
- GRB 130627B: Swift/UVOT Upper Limits
- GRB 130627A: Swift/UVOT Upper Limits
- GRB 130627A: Swift-XRT refined Analysis
- GRB 130627B: Possible Swift-XRT afterglow detection
- Swift trigger 559221 is likely a false trigger coincident with IGR J17544-2619
- GRB 130626A: RATIR Optical Observations
- GRB 130626A, Swift-BAT refined analysis
- GRB 130627A: Fermi GBM detection
- GRB 130623A: Fermi GBM detection
- GRB130627B: Swift/UVOT Observations
- GRB 130627B: Swift-XRT observations
- GRB 130626A: Swift-XRT possible detection and UVOT upper limits
- GRB 130627B: Swift detection of a burst
- GRB 130627A: Swift-XRT observations
- GRB 130627A: Swift/UVOT Observation
- GRB 130627A: Swift detection of a burst
- Swift Trigger 559108 is not astrophysical