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"- GRB 131110A BAT refined analysis
- GRB 131031A: Mondy optical observations
- GRB 131108A: ISON Blagoveshensk upper limit
- GRB 131108A: optical observations
- GRB 131110A found in ground analysis of BAT slew event data
- GRB 131108A: Continued RATIR Optical and NIR Observations
- GRB 131030A: MITSuME Akeno Optical observation
- Konus-Wind observation of GRB 131108A
- GRB 131108A: AGILE/GRID observation
- GRB 131108A: CARMA 3mm detection
- GRB 131108A: Fermi GBM observation
- GRB 131108A: Swift/UVOT Detection
- GRB 131108A: RATIR Optical and NIR Observations
- GRB 131108A: Swift-XRT observations
- GRB 131108A: TAROT-Calern optical observation
- GRB 131108A: Fermi-LAT refined analysis
- GRB 131108A: NOT optical observations
- GRB 131108A: Redshift from 10.4m GTC
- GRB 131108A: 1.23m CAHA optical candidate
- GRB 131108A: Swift detection of a possible X-ray afterglow
- IPN triangulation of GRB 131108A - correction
- IPN triangulation of GRB 131108A
- GRB 131108A Tiled Swift observations
- GRB 131108A: Fermi-LAT onboard detection of a burst
- GRB 131030A: RATIR Optical and NIR Upper Limits
- GRB 131030A: Continued RATIR Optical and NIR Observations
- GRB 131031A: Swift-XRT afterglow confirmation
- GRB 131029A: Suzaku WAM observation of the prompt emission
- GRB 131105A, Swift-BAT refined analysis
- GRB 131105A: Swift-XRT refined Analysis
- GRB 131103A: Swift-BAT refined analysis
- GRB 131030A: Swift-BAT refined analysis
- GRB 131105A: Fermi GBM observation
- GRB 131105A: Swift/UVOT Upper Limits
- GRB 131024B: Suzaku WAM observation of the prompt emission
- Konus-Wind observation of GRB 131105A
- GRB 131103A: VLT/X-shooter redshift
- GRB 131105A: VLT/X-shooter redshift
- GRB 131105A: TAROT La Silla observatory optical observations
- GRB 131105A: Enhanced Swift-XRT position
- GRB 131105A: VLT/X-shooter optical afterglow candidate
- GRB 131105A: Swift detection of a burst
- GRB 131103A: NOT and VLT observations
- GRB 131030A: Continued RATIR Optical and NIR Observations
- GRB 131103A: Swift/UVOT Detection
- GRB 131103A: Enhanced Swift-XRT position
- GRB 131103A: Swift-XRT refined Analysis
- GRB 131103A: Swift detection of a burst
- GRB 131031A: RATIR Optical and NIR Observations and Upper Limits
- GRB131031A: RATIR Optical and NIR Observations
- GRB 131018B: RATIR Optical/NIR Observations
- GRB 131030A: Continued RATIR Optical and NIR Observations
- GRB 131030A: the 2nd epoch of SAO RAS observations
- GRB 131031A: Fermi GBM detection
- GRB 131031A: Swift/UVOT Upper Limits
- LOAO B,R Observation of GRB131030A
- GRB 131018B: Further Swift-XRT observations.
- GRB 131030A - RoboPol optical afterglow polarimetry
- GRB 131031A: MASTER optical observation
- Konus-Wind observation of GRB 131031A
- GRB 131030A: Bassano Bresciano Observatory optical observations
- GRB 131031A: 1.23m CAHA afterglow candidate
- GRB131030A : xinglong TNT optical observation
- GRB 131031A: Swift-XRT observations
- GRB 131030A: P60 observations
- GRB 131031A: 1.23m CAHA I-band and 1.5m OSN R-band observations of Swift/BAT error circle
- GRB 131031A found in ground analysis of BAT data
- GRB 131030A: RATIR Optical and NIR Observations
- GRB 131030A: TAROT La Silla observatory optical observations
- GRB 131030A: T21 optical observations
- GRB 131030A: Swift-XRT refined Analysis
- GRB 131030A: Enhanced Swift-XRT position
- GRB 131024C: ICSP discovery of a burst in X-rays by balloon borne study
- GRB 131030A: Swift/UVOT Detection
- Konus-Wind observation of GRB 131030A
- GRB 131030A: SAO RAS optical observations
- GRB 131030A: 1.23m CAHA BVRI-band observations
- GRB 131030A: D50+BART detection and light curve optical decay
- GRB 131029A: Nanshan optical observations
- GRB 131030A: Spectroscopy from 10.4m GTC
- GRB 131030A: NOT redshift
- GRB 131030A - Liverpool Telescope Optical Afterglow Confirmation
- GRB 131030A: MASTER optical observation
- GRB 131029A: Swift-XRT follow up
- GRB 131030A: Watcher OT detection
- GRB 131030A: Swift detection of a burst with an optical counterpart
- GRB 131029A: Fermi GBM observation
- GRB 131029A Tiled Swift observations
- GRB 131029A: Fermi-LAT detection of a burst
- Konus-Wind observation of GRB 131028A
- IPN Triangulation of GRB 131028A (long/bright)
- GRB 131028A: Fermi GBM detection
- GRB 131011A: ATCA 34GHz upper limit
- Swift 575905/GRB 131026A: optical observations
- Swift-BAT Trigger 575905 is probably not a real source
- GRB 131024B: AAO optical upper limit
- GRB 131024B: Mondy optical upper limits
- GRB 131024B: MASTER prompt optical observation
- Swift Trigger 575905/ GRB 131026A: MITSuME Okayama and Ishigakijima Optical upper limits
- Swift Trigger 575905/possible GRB 131026A: Swift-XRT observations