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"6659 results found.
- GRB 100725A: Swift XRT refined analysis
- GRB 100724B: Fermi LAT and GBM analysis
- GRB 100724B: Fermi GBM detection
- GRB 100724A: Swift XRT refined analysis
- GRB 100722A: Fermi GBM detection
- GRB 100713A: optical observation in Maidanak
- GRB 100713A: Swift XRT refined analysis
- GRB 100713A : IRSF/SIRIUS NIR upper limits
- GRB100713A: Swift X-ray afterglow detection
- GRB 100707A: Fermi LAT detection
- GRB 100707A: Fermi GBM detection
- GRB 100628A: Swift XRT/UVOT refined analysis
- GRB 100704A: Swift XRT refined analysis
- GRB 100704A: Fermi GBM observation
- GRB 100625A: Fermi GBM detection
- GRB 100628A: Swift XRT refined position
- GRB100628A : MOA optical upper limit
- GRB 100628A: Swift XRT detection of a possible X-ray afterglow
- GRB 100625A : IRSF/SIRIUS NIR upper limit
- GRB 100625A: Swift-XRT Team refined analysis
- GRB 100621A: IRSF/SIRIUS NIR Observation
- GRB 100621A: Swift XRT refined analysis
- GRB 100619A: Fermi GBM detection
- GRB 100619A: Swift/UVOT Upper Limits
- GRB 100619A: Swift-XRT refind analysis
- GRB 100615A: Swift-XRT refined analysis
- GRB 100614A: Swift-XRT refined analysis
- GRB 100615A: PAIRITEL NIR Upper Limits
- GRB 100606A Swift-XRT refined analysis
- GRB 100606A: Prompt enhanced Swift-XRT position
- GRB 100111A: Maidanak optical observations
- Swift UVOT and UVOT-enhanced XRT position for GRB 100528A
- GRB 100528A: Fermi GBM observation
- GRB 100526B: Swift-XRT confirmation of fading afterglow
- GRB 100526A: Swift XRT refined analysis
- GRB 100522A: Fermi GBM observation
- GRB 100522A: Swift XRT refined analysis
- GRB 100522A: NIR observations from CAHA
- GRB 100518A: Swift-XRT refined analysis
- GRB 100518A: Swift target of opportunity observation of the INTEGRAL burst
- GRB 100514A: Swift XRT refined analysis
- GRB 100513A: Swift XRT refined analysis
- GRB 100513A: Lick observations and R-band dropout
- GRB 100513A: PAIRITEL continued observations and confirmation of fading
- GRB 100513A: PAIRITEL NIR afterglow candidate
- GRB 100510A: Fermi GBM detection/observation
- GRB 100511A: Fermi GBM detection/observation
- Swift-BAT trigger 421695 is likely not astrophysical
- GRB 100508A: Swift-XRT Refined analysis
- GRB 100504A: Fermi GBM observation
- GRB 100418A: Flattening of the Swift/UVOT Optical Light Curve
- GRB 100504A: Swift-XRT refined analysis
- GRB 100503A: Fermi GBM detection
- GRB 100427A: Swift XRT and UVOT Upper Limits
- GRB 100425A: Swift XRT refined analysis
- GRB 100424A: PAIRITEL NIR Upper Limits
- GRB 100424A: Prompt enhanced Swift-XRT position.
- GRB 100418A: Continued PAIRITEL NIR Observations
- GRB 100418A: Continuing Swift/UVOT Observations
- GRB 100418A: further GROND observations and light curve fit
- GRB 100418A: RTT150 optical observations
- GRB 100420A: XRT refined analysis
- GRB 100418A: RTT150 observations during the optical afterglow maximum
- GRB 100418A PAIRITEL NIR Observations
- GRB 100418A: Swift-XRT Refined Analysis
- GRB100414A: SAO RAS optical observations
- GRB 100413B: Swift Confirmation of Burst
- GRB 100414A: Swift-XRT detection of a possible X-ray afterglow
- GRB 100414A: Fermi GBM detection
- GRB100414A: Fermi LAT detection
- GRB 100413A: Swift/UVOT Upper Limits
- GRB 100413A: Swift-XRT Refined Analysis
- Spin down rate and inferred dipole magnetic field of the new soft gamma-ray repeater SGR 1833-0832
- Swift/BAT trigger 417974 (GRB100401A): Swift/XRT observations
- GRB 100316A: R-band limit
- GRB 100331B: Swift/XRT possible afterglow candidate
- GRB 100325A: Fermi LAT detection
- GRB 100322A: Fermi GBM detection
- SGR 1833-0832: Archival Chandra Observations
- Possible pulsation period in SGR 1833-0832
- Discovery of the Spin Period of SGR 1833-0832
- Probable SGR 1833-0832: Swift-XRT refined analysis
- Swift-XRT refined position of the probable new SGR 1833-0832
- GRB 100316D: Pre-burst emission measured by BAT
- GRB 100316D: Swift XRT enhanced position and further refined analysis
- GRB 100316B: Swift-XRT refined analysis
- GRB 100316D: Swift-BAT refined analysis
- GRB 100316C: Swift-XRT team refined analysis
- GRB 100316A: Swift-XRT refined analysis
- GRB 100305A: Swift-XRT refined analysis
- GRB 100305A: PAIRITEL NIR Upper Limits
- GRB 100302A: Swift-XRT refined analysis
- GRB 100224B: Fermi GBM detection
- GRB 100225A: Fermi LAT detection
- GRB 100225A: Fermi GBM detection
- GRB 100223A: Fermi GBM detection
- GRB 100219A: XRT refined analysis
- GRB 100216A: Swift/UVOT Observations
- GRB 100216A: XRT Refined Analysis
- GRB 100213B: PAIRITEL NIR Upper Limits