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"2795 results found.
- GRB 100621A: Swift/UVOT observations
- GRB 100514A: Swift/UVOT Observations
- Trigger 421695: Swift detection of a possible burst
- GRB 100508A: GROND Detection of the optical afterglow
- GRB 100508A: Swift detection of a burst
- Trigger 421072: Possible Swift detection of a GRB or transient
- GRB 100418A: RTT150 optical observations
- GRB 100418A: Possible Evidence for a Supernova
- Trigger 420256: Swift detection of a possible GRB
- GRB100418A: REM possible afterglow detection
- GRB 100413A: GMRT observation of radio afterglow
- GRB 100418A: Swift detection of a burst with a possible optical afterglow
- GRB 100414A: Swift-XRT detection of a possible X-ray afterglow
- GRB 100331B: Swift/XRT possible afterglow candidate
- GRB 100331B: SuperAGILE Localization of a Long GRB
- GRB 100322B or possible Galactic transient detected in ground analysis of BAT data
- Possible pulsation period in SGR 1833-0832
- GRB 100319A: Swift detection of a burst; possible SGR
- GRB 100316D: Possible Supernova
- GRB 100316D: Further Gemini observations
- GRB 100316 optical candidate from 1.23m CAHA telescope
- GRB 100316 optical candidate from 1.23m CAHA telescope
- GRB 100316A: Swift-XRT detection
- GRB 1000302A : A possible afterglow candidate
- GRB 100213A: Swift XRT refined analysis
- GRB 100213B: NOT optical observations
- GRB 100119A: Swift detection of a burst
- GRB100117A: Possible afterglow from NOT observation
- GRB 100115A: SARA Astrometry
- GRB 100115A: Swift-XRT candidate afterglow
- Swift/BAT Detects an Outburst from XTE J1901+014
- Swift Trigger 381591 is probably not a burst
- GRB 091231: GROND NIR observations
- Trigger 381591: Swift detection of a possible burst
- Trigger 381434: Swift detection of a possible burst
- GRB 091117: Swift-XRT late time observations
- Swift trigger 379449 (possible GRB) is not a burst
- GRB 091215: Faulkes Telescope North observations
- Trigger 379449: Swift detection of a possible burst
- GRB 091127: Skynet/PROMPT Observations of Possible Host Galaxy
- GRB 091123: Fermi GBM detection of a very long burst
- Swift trigger 377436 (possible GRB 091130A) is not a burst
- GRB 091130: Swift detection of a possible burst
- GRB 091127: MASTER early optical transient polarimetry
- GRB 091117A: Swift/UVOT followup observations
- GRB 091117 BAT refined analysis
- GRB 091112: Swift detection of a possible burst
- GRB 091109A: GROND and VLT observations
- GRB 091109B: VLT observations
- GRB 091102: Swift/XRT localization
- GRB 091018: Skynet/PROMPT Observations of Possible Host Galaxy
- GRB 091020: Late TLS detection
- GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
- Fwd: GRB 091003: Possible Supernova Component Retraction
- GRB 091003: Possible Supernova Component
- GRB 091003: Gemini-N redshift of possible host galaxy
- GRB 091010: optical afterglow candidate rejection
- GRB 091010: Swift-XRT position
- GRB 091003: Lick observations and possible SDSS host galaxy
- GRB 090831B: Swift detection of a possible burst
- GRB 090823: Swift XRT possible detection of the X-ray afterglow
- GRB 090817: Swift/UVOT Observations of a Possible Late-Time Brightening
- GRB 090817: aphotometry of USNO-B1.0 341-0096763
- GRB 090814B: Swift-XRT detection of a possible afterglow.
- GRB 090814A: Swift-BAT refined analysis
- GRB 090809: Swift detection of a burst with a possible optical counterpart
- GRB 090807: Swift-XRT refined analysis
- GRB 090807, Swift-BAT refined analysis
- GRB 090727: Liverpool Telescope possible OT candidate
- GRB 090726: Swift-XRT position of probable counterpart
- GRB 090720: Gemini-North Imaging and Optical Afterglow
- GRB 090715B: Swift detection of a burst with a possible optical counterpart
- GRB 090621B: MTM-500 optical observations
- Possible GRB090705: Swift-XRT observations
- GRB 090705: PAIRITEL NIR Observations
- GRB 090705: Swift detection of a possible burst
- GRB 090404: Deep optical imaging and possible host association (correction)
- GRB 090404: Deep optical imaging and possible host association
- GRB 090628: Swift detection of a burst
- GRB 090621A: Swift-BAT refined analysis
- Ignore GCN/Swift-BAT Lightcurve Notices for trigger 353567
- GRB 090531: Swift-BAT refined analysis
- GRB 090529: Swift-BAT refined analysis
- GRB 090516B: Fermi GBM detection
- GRB090510: VLT/FORS2 spectroscopic redshift
- GRB 090510: Swift/UVOT host galaxy candidates
- GRB 090418A: optical observation
- GRB 090424: optical observations
- GRB090429B: Gemini-N infrared IR candidate
- GRB 090423: pseudo burst at z=1 and its relation to GRB 080913
- GRB 090423: Swift/BAT spectral lag results
- GRB 090422: Liverpool Telescope possible candidate
- VLA observations of short burst GRB 090417A
- GRB 090417B: optical observations
- GRB 090412: Fermi GBM detection
- Swift-BAT trigger 348781: almost certainly not a burst
- Fermi GBM Detection of a weak source
- GRB 090404: Swift detection of a burst
- GRB 090401B: Swift detection of a burst
- GRB 090328B: MASTER-Irkutsk prompt optical short burst observations