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"27394 results found.
- Swift trigger 358760 is probably a noise event
- GRB 090717A: Suzaku WAM observation of the prompt emission
- GRB 090709A : Quick look analysis of the Suzaku observation
- GRB 090728: Swift-BAT refined analysis
- 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, RIMOTS optical upper limits
- GRB 090728A: Faulkes Telescope North Optical Afterglow Candidate
- GRB 090728: Swift detection of a burst
- GRB 090727: Swift-BAT refined analysis
- GRB 090727: Swift-XRT refined analysis
- GRB 090727: Liverpool Telescope Afterglow Confirmation and Optical Flare
- GRB 090727: Liverpool Telescope possible OT candidate
- GRB 090727: Swift detection of a burst
- GRB090726: Swift/UVOT observations
- GRB 090726, Swift-BAT refined analysis
- GRB 090726: D50 optical observations
- GRB 090711: Fermi GBM detection
- GRB090726: 6-meter telescope redshift
- GRB 090726: Swift-XRT Team refined analysis
- 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
- Swift Trigger 358354 is not a GRB
- Konus-Wind and Konus-RF observations of GRB 090719
- Konus-RF and Konus-Wind observations of GRB 090718B
- Fermi Gamma-ray Burst Monitor triggers 269935914 through 270021937 are not GRBs
- Konus-Wind observations of bright hard GRB 090720B
- IPN Triangulation of bright GRB 090720B
- 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 090720 Source found in ground processing of Swift-BAT data
- 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 090715A: Suzaku WAM observation of the prompt emission
- GRB 090709A - CARMA mm Observations
- GRB 090715A: VLA observations
- Konus-Wind observations of short/hard GRB 090715A
- GRB 090715B: MASTER optical limit
- GRB 090715A: Swift-BAT refined analysis
- GRB 090715B: Swift/UVOT followup observations
- GRB 090715B: break in the optical afterglow decay
- GRB 090715B: Swift XRT Refined Analysis
- GRB 090715B: Swift-BAT refined analysis
- GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
- GRB 090715B: Swift detection of a burst with a possible optical counterpart
- GRB 090715A: ROTSE-III Optical Limits
- GRB 090715: Swift detection of a short hard burst
- Swift satellite anomaly
- GRB090713 optical limit by "Pi of the Sky"
- GRB 090712: Fermi GBM observation
- GRB 090713: Fermi GBM detection
- GRB 090712: Swift-BAT refined analysis
- GRB 090712: Swift detection of a burst
- GRB 090709A: Xinglong TNT optical upper limit
- GRB 090709A: Suzaku WAM observation of the prompt emission
- GRB 090709A: Swift UVOT upper limits
- GRB 090709B: Fermi GBM detection
- GRB 090709A: confirmation of the periodicity in the SPI-ACS data
- GRB 090709A: P60 Observations
- GRB 090709A: Quasiperiodic variations in the BAT light curve
- GRB 090709A: NOT optical observations
- GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
- GRB 090709A: Swift XRT Refined Analysis
- GRB 090709B, Swift-BAT refined analysis
- GRB 090709A: Swift-BAT refined analysis
- GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
- GRB 090709A: Wyoming Infrared Observatory NIR upper limits
- GRB 090709A, RIMOTS optical upper limits
- GRB 090709B: Swift detection of a burst
- GRB 090708 : Fermi GBM detection
- GRB 090626: Suzaku WAM observation of the prompt emission
- GRB 090709: PAIRITEL NIR Upper Limits
- GRB 090704: Fermi GBM observation
- GRB 090709: ROTSE-III Optical Limits
- GRB 090709: Swift detection of a bright burst
- GRB 090708: Early RAPTOR Optical Limits
- GRB 090708, Swift-BAT refined analysis
- GRB 090708: ROTSE-III Optical Limits
- GRB 090708: Swift detection of a burst
- GRB 090704: a long GRB found in INTEGRAL off-line analysis
- GRB 090706: Fermi GBM detection
- Swift-BAT trigger 356516 is not a GRB
- Possible GRB090705: Swift-XRT observations
- GRB 090705: PAIRITEL NIR Observations
- GRB 090705: Swift detection of a possible burst
- GRB 090703: Fermi GBM detection
- GRB 090702: UVOT upper limits
- XRF 090702: Swift-XRT afterglow position