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"19093 results found.
- GRB 161004A: Swift/UVOT Detection
- GRB 161004A: Enhanced Swift-XRT position
- GRB 161004A: Bassano Bresciano Observatory upper limit
- GRB 161004A: TSHAO optical observations
- GRB 161004A: Swift detection of a burst with a possible optical counterpart
- GRB 161001A: MASTER-OAFA and MASTER-SAAO early optical observations
- GRB 161001A: GROND afterglow candidate
- GRB 161001A: X-shooter spectroscopy, candidate host galaxy and redshift
- GRB 161001A: Swift/UVOT Upper Limits
- GRB 161001A: Enhanced Swift-XRT position
- GRB 161001A: Swift detection of a burst
- GRB 160927A: Magellan imaging
- GRB 160927A: Swift/UVOT Upper Limits
- GRB 160927A: Bassano Bresciano Observatory optical upper limit
- GRB 160927A: NOT optical observations
- GRB 160927A: GROND Observations
- GRB 160927A: Enhanced Swift-XRT position
- GRB 160927A: TNG optical afterglow confirmation
- GRB 160927A: RTT150 optical afterglow candidate
- GRB 160927A: Swift detection of a short hard burst
- GRB160910A: AstroSat CZTI detection
- XRT refined analysis for GRB 160925A
- GRB 160925A/MASTER optical transient: Mondy optical observations
- GRB 160925A: MITSuME Akeno Optical Observations
- GRB 160925A: Swift ToO observations
- GRB 160917A: Mondy afterglow confirmation
- GRB 160910A: TSHAO optical observations
- GRB 160917A: RATIR Optical and NIR Observations
- GRB 160917A: Swift/UVOT Detection
- GRB 160917A: Mondy optical observations
- GRB 160917A: OSN I-band upper limits
- GRB 160917A: Enhanced Swift-XRT position
- GRB 160917A: Swift detection of a burst
- GRB 160910A: Swift/UVOT Detection
- GRB 160912A: RATIR Optical and NIR Observations
- GRB 160912A: Swift/UVOT Weak Afterglow Detection
- GRB 160912A: Mondy optical observations
- GRB 160910A: Mondy optical observations
- GRB 160912A Liverpool Telescope optical afterglow
- GRB 160912A: Enhanced Swift-XRT position
- GRB 160910A: Global MASTER Net OT detection before LAT alert
- GRB 160912A: Swift detection of a burst
- GRB 160910A: XRT results and corrections to GCN 19905 & 19906
- GRB 160910A: NOT afterglow confirmation
- GRB 160910A: Afterglow detection from OSN
- GRB 160910A: Tiled Swift observations
- GRB 160908A: CALET Gamma-Ray Burst Monitor detection
- GRB 160910A: Fermi-LAT detection
- GRB 160905A: Swift/UVOT Detection
- GRB 160905A: Enhanced Swift-XRT position
- GRB 160905A: Fermi-LAT detection
- IceCube HESE 160814: MASTER OT J130845.02-323254.9 as the possible source of the high energy neutrino
- GRB 160905A: Swift detection of a burst with an optical counterpart
- GRB 160829A: Swift ToO observations
- GRB 160827A: Swift detection of a burst
- Swift Trigger 710022 is very likely noise
- GRB 160826A: Swift/UVOT Upper Limits
- GRB 160825A: not localized by Swift
- GRB 160826A: Swift detection of a burst
- GRB 160825A: Swift ToO observations
- GRB 160824A: ISON/Terskol optical observations
- GRB 160824A: Swift/UVOT Possible Afterglow Detection
- GRB 160824A: Bassano Bresciano Observatory upper limits
- GRB 160824A: Swift-XRT refined Analysis
- GRB 160824A: Enhanced Swift-XRT position
- GRB 160824A: Swift detection of a burst
- IPN Triangulation of GRB 160822A (short/hard)
- IPN Triangulation of GRB 160820A (short/hard)
- GRB 160821B: GTC follow-up observation
- GRB 160822672: Fermi GBM detection
- GRB 160821B: Swift-BAT refined analysis
- GRB 160821B: Swift-XRT refined Analysis
- GRB 160821B: Swift/UVOT Upper Limits
- GRB 160821B: Enhanced Swift-XRT position
- GRB 160821B: NOT optical afterglow candidate
- GRB 160821B: Swift detection of a short burst
- GRB 160821A: TAROT Calern observatory optical detection
- GRB 160816A: TSHAO optical observations
- GRB 160816A: ISON/UAFO optical observations
- GRB 160816A: Further RATIR Optical and NIR Observations
- GRB 160816A: RATIR Optical and NIR Afterglow Confirmation
- GRB 160816A iTelescope observation
- Fermi GBM Observations of IceCube-160806A
- GRB 160816A: Swift/UVOT Detection
- GRB 160816A: RATIR Optical and NIR Observations
- GRB 160816A: Swift ToO observations
- GRB 160815A: Swift/UVOT Detection
- GRB 160815A: Swift-XRT refined Analysis
- GRB 160815A: Enhanced Swift-XRT position
- GRB 160815A: Swift detection of a burst
- INTEGRAL/SPI-ACS and IBIS_VETO search for prompt gamma-ray counterpart of IceCube-160806A
- Konus-Wind observation of GRB 160806A
- IPN Triangulation of GRB 160806A
- Swift Trigger 707545 is likely 4U 1850-03/GS1843-02
- Swift Trigger 707517 is probably not a GRB
- GRB 160804A: RATIR Optical and NIR Observations
- GRB 160804A: TSHAO optical observations
- GRB 160804A: ISON/UAFO optical observations
- GRB 160804A: GROND observations
- GRB 160804A: SAO RAS optical observations