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"27573 results found.
- GRB 090812: Swift detection of a burst with an optical counterpart
- GRB 090807B: Fermi GBM detection
- GRB 090809: Further NOT optical observations
- VLA radio upper limit on GRB 090809
- GRB 090809: WHT observations
- GRB 090809 X-shooter redshift
- GRB 090809B: Fermi GBM detection
- GRB 090809: Swift-XRT refined analysis
- GRB090809: Swift/UVOT observations
- GRB 090809: Enhanced Swift-XRT position
- GRB 090809: afterglow confirmation at the NOT
- GRB 090809: Swift detection of a burst with a possible optical counterpart
- GRB 090807: Liverpool Telescope observations
- GRB 090807: MITSuME optical upper limit
- GRB 090807: Swift/UVOT Upper Limits
- GRB 090807: Swift-XRT refined analysis
- GRB 090807, Swift-BAT refined analysis
- GRB 090807: Enhanced Swift-XRT position
- GRB 090807: Swift detection of a burst
- GRB 090802B: Fermi GBM detection
- GRB 090802: Fermi GBM detection
- GRB 090726: optical observation
- Swift-BAT trigger 358760 is most likely not a GRB
- Swift trigger 358760 is probably a noise event
- GRB 090709A : Quick look analysis of the Suzaku observation
- GRB 090727: GRT Optical Observation
- GRB 090728: Swift XRT refined analysis
- GRB 090727: optical observations
- GRB 090726: GRT Optical Observation
- GRB 090727: Swift/UVOT Upper Limits
- GRB 090728: Swift/UVOT Upper Limits
- GRB 090728: Enhanced Swift-XRT position
- GRB 090727: I-band observations from 1.23m CAHA
- GRB 090728A: Faulkes Telescope North Optical Afterglow Candidate
- GRB 090728: Swift detection of a burst
- GRB 090727: Swift-XRT refined analysis
- GRB 090727: Liverpool Telescope Afterglow Confirmation and Optical Flare
- GRB 090727: Enhanced Swift-XRT position
- GRB 090715B: Late-time Lick 3m observations
- GRB 090727: Liverpool Telescope possible OT candidate
- GRB 090727: Swift detection of a burst
- GRB090726: Swift/UVOT observations
- GRB 090726: Afterglow candidate photometryfrom Crni Vrh
- GRB 090726: D50 optical observations
- GRB 090711: Fermi GBM detection
- GRB090726: 6-meter telescope redshift
- GRB 090726: Swift-XRT Team refined analysis
- GRB 090726: Enhanced Swift-XRT position
- GRB 090726: optical transient candidate
- GRB 090726: Swift/UVOT Finding Chart Observation
- GRB 090726: Swift-XRT position of probable counterpart
- GRB 090726: Swift detection of a burst
- GRB 090720: Gemini-North Imaging and Optical Afterglow
- GRB 090720B: Fermi GBM detection
- Swift XRT and UVOT refned analysis of GRB 090720
- GRB 090709A: Swift XRT Timing Analysis
- GRB 090715B: VLA radio detection
- GRB 090717B: Fermi GBM detection
- GRB 090717: Fermi GBM detection
- GRB 090719: Fermi GBM detection
- GRB 090718B: Fermi GBM detection
- GRB 090718: Fermi GBM detection
- GRB 090720: Fermi GBM detection
- GRB 090715B: further NOT optical observations
- GRB 090709A - CARMA mm Observations
- GRB 090715B: Swift/UVOT followup observations
- GRB 090715B: break in the optical afterglow decay
- GRB 090715B: Enhanced Swift-XRT position
- GRB 090715B: Observation of the optical afterglow
- GRB 090715B: Swift XRT Refined Analysis
- GRB090715B: WHT redshift
- GRB 090715B: NOT optical observations
- GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
- GRB 090715B: Swift detection of a burst with a possible optical counterpart
- GRB 090715: Swift detection of a short hard burst
- Detection of GRB 090618 by RT-2 Experiment onboard the CORONAS-PHOTON Satellite
- Swift satellite anomaly
- GRB 090713: Fermi GBM detection
- GRB 090712: Swift detection of a burst
- GRB 090709A: Xinglong TNT optical upper limit
- VLA radio observations of GRB 090709A
- GRB 090621B: MTM-500 optical observations
- GRB 090709A: deep optical observation with the 10.4m GTC
- GRB090709A : WSRT Radio observation
- GRB 090709A: Swift UVOT upper limits
- GRB 090709A: WHT LIRIS observations
- GRB 090709B: Fermi GBM detection
- GRB 090709A: evidence for a very red afterglow at low z
- GRB 090709A: P60 Observations
- GRB 090709A: Quasiperiodic variations in the BAT light curve
- GRB 090709A: Swift XRT Refined Analysis
- GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
- GRB 090709A: Wyoming Infrared Observatory NIR upper limits
- GRB 090709A: Enhanced Swift-XRT position
- GRB 090709A - PAIRITEL Discovery of a Red Afterglow
- GRB 090709A: Subaru NIR observation
- GRB 090709B: Swift detection of a burst
- GRB 090708 : Fermi GBM detection
- GRB 090709: Faulkes Telescope North Upper Limits
- GRB 090709: PAIRITEL NIR Upper Limits