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"
6191 results found.
- GRB 130425A: Fermi GBM detection
- GRB 130420A: ROTSE-III data analysis
- GRB 130420B: Fermi GBM observation
- GRB 130420B: Swift-XRT refined Analysis
- GRB 130420A: Fermi GBM observation
- GRB 130420A: ISON-NM optical observations
- GRB 130420A: Swift-XRT refined Analysis
- GRB 130420A: PAIRITEL NIR detections
- GRB 130418A: Swift-XRT refined Analysis
- GRB 130418A: T18 and T21 optical observations
- GRB 130418A, Swift-BAT refined analysis
- GRB 130418A: REM NIR observations
- GRB 130418A: Swift detection of a burst with an optical counterpart
- GRB 130408A: Swift-XRT refined Analysis
- Swift/XRT observation of GRB 130327B
- GRB 130306A: Confirmation of the X-ray Afterglow
- Swift Trigger 552142 is a noise event
- GRB 130327B: Fermi-LAT detection of a burst
- GRB 130327B: Fermi GBM detection
- Swift Trigger 552142: a possible GRB
- GRB 130327A: Swift-XRT refined Analysis
- GRB 130327A: PAIRITEL NIR Afterglow Candidate
- GRB 130325A: Fermi LAT detection
- GRB 130325A: Fermi GBM detection
- GRB 130315A: Swift-XRT refined Analysis
- Swift XRT observations of GRB 130310A
- GRB 130313A: Fading X-ray Afterglow
- GRB 130313A: Swift-XRT refined Analysis
- Swift XRT observations of GRB 130310A
- GRB 130306A: Swift Detection of a Possible Afterglow
- GRB 130310A: Fermi GBM detection
- GRB 130305A: Further Swift-XRT Observations
- GRB 130307A: Fermi GBM detection
- GRB 130305A: Swift/XRT detection of the afterglow
- GRB 130305A: Fermi GBM observation
- GRB 130216A: Swift/XRT observations
- GRB 130219A: Fermi GBM detection
- GRB 130216B: Swift/XRT observations
- GRB 130216A: Fermi GBM observation
- GRB 130216B: Fermi GBM observation
- GRB 130216B: P200 NIR Observations
- GRB 130216A: P200 NIR Observations
- GRB 130215A: Additional P200 NIR observations
- GRB 130215A: P200 NIR observations
- GRB 130215A: Fermi GBM detection
- GRB 130215A: iTelescope T11 observations
- GRB 130215A: REM NIR observations
- Swift GRB130206A: late XRT observations.
- GRB 121128A: optical observations
- GRB 130211A: Swift-XRT refined Analysis
- GRB 130206A: Fermi LAT Observations
- GRB 130206A: Fermi GBM observation
- GRB 130206A: XRT and UVOT follow-up observations.
- GRB 130206A: Swift-XRT observations
- GRB 130131B: Swift-XRT refined Analysis
- GRB 130131A: Swift-XRT refined Analysis
- GRB 130127A: Fermi GBM detection
- GRB 130122A: Swift-XRT refined Analysis
- GRB 130102A: Swift-XRT refined Analysis
- GRB 121229A: Swift-XRT refined Analysis
- GRB 121226A: Swift-XRT refined Analysis
- GRB 121226A: Optical Observations
- GRB 121225B: Fermi GBM observation
- GRB 121225B: Fermi LAT Detection
- GRB 121217A theoretical estimate of redshift and of supernova occurrence
- GRB 121217A: Fermi GBM observation
- GRB 121217A: Swift-XRT refined Analysis
- GRB 121209A: LOAO Observation
- GRB121212A: NOT optical imaging
- GRB 121211A: Fermi GBM observation
- GRB 121212A: PAIRITEL NIR Observations
- GRB 121212A: Swift-XRT refined Analysis
- GRB 121211A: Swift-XRT refined Analysis
- GRB 121209A: Swift-XRT refined Analysis
- GRB 121209A: GROND optical afterglow candidate
- GRB 121209A: PAIRITEL NIR Observations
- GRB 121202A: Swift-XRT refined Analysis
- GRB 121202A: Fermi GBM observation
- GRB 121201A: GROND afterglow observations and photometric redshift
- GRB 121201A: Swift-XRT refined Analysis
- GRB 121128A: Swift-XRT refined Analysis
- GRB 121122A: Fermi GBM observation
- GRB 121128A: Fermi GBM observation
- GRB 121117A: Terskol obseravtions
- GRB 121123A: Swift/UVOT Observations
- GRB 121125A: Swift-XRT refined Analysis
- GRB 121125A: Fermi GBM Observation
- GRB 121123A: Swift-XRT refined Analysis
- GRB 121123A: Fermi GBM observation
- GRB 121117A: Optical observations
- GRB 121117A: Swift-XRT refined Analysis
- GRB 121108A: Swift-XRT refined Analysis
- GRB 121031A: Fermi GBM detection
- GRB 121031A: Swift-XRT refined Analysis
- GRB 121102A: Swift-XRT refined Analysis
- GRB 121029A: Fermi GBM detection
- GRB 121027A: Swift-XRT refined Analysis
- GRB 121028A: Swift-XRT refined Analysis
- GRB 121025A: Swift-XRT observation
- GRB 121024A: Swift/UVOT Observations