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.
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"
913 results found.
- Fermi GBM Sub-Threshold Detection of GRB 200517A
- GRB 200517A: Swift-XRT afterglow detection
- GRB 200514A: AstroSat CZTI detection
- GRB 200517A: Tiled Swift observations
- GRB 200517A: MAXI/GSC detection
- GRB 200514A: MITSuME Akeno optical upper limits
- GRB 200514A: CALET Gamma-Ray Burst Monitor detection
- GRB 200514A: MAXI/GSC detection
- Konus-Wind observation of a very intense bursting activity of SGR 1935+2154
- SGR 1935+2154: MAXI/GSC detection
- GRB 200320B: MAXI/GSC detection
- LIGO/Virgo S200316bj: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200311bg: Coverage and upper limits from MAXI/GSC observations
- GRB 200310A: MAXI/GSC detection
- LIGO/Virgo S200302c: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200225q: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200224ca: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200219ac: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200213t: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200208q: Coverage and upper limits from MAXI/GSC observations
- GRB 200205A = Swift J0840.7-3516, A newly discovered transient X-ray Pulsar
- GRB 200205A / Swift trigger 954304: VLT optical observations
- GRB 200205A: MAXI/GSC detection
- MAXI GRB200205.29: Global MASTER-Net observations report
- LIGO/Virgo S200129m: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200128d: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200115j: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200114f: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200112r: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200105ae: Coverage and upper limits from MAXI/GSC observations
- GRB 200105A: MAXI/GSC detection
- LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191216ap: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191213g: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191205ah: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191204r: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191129u: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191110af: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191109d: Coverage and upper limits from MAXI/GSC observations
- GRB 191106A: Swift/UVOT Upper Limits
- LIGO/Virgo S191105e: Coverage and upper limits from MAXI/GSC observations
- Fermi trigger No 594557071: Global MASTER-Net observations report
- LIGO/Virgo S190930t: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190930s: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190924h: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190924h: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190923y: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190910h: Coverage and upper limits from MAXI/GSC observations
- Swift Trigger 924641 is an outburst from MAXI J1807+132
- LIGO/Virgo S190910d: Coverage and upper limits from MAXI/GSC observations
- GRB 190823A: Swift-XRT afterglow detection
- LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations
- GRB 190828A: Swift-XRT observations
- GRB 190828A: Tiled Swift observations
- LIGO/Virgo S190828l: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190828j: Coverage and upper limits from MAXI/GSC observations
- GRB 190828A: MAXI/GSC detection
- GRB 190823A: Swift-XRT observations
- GRB 190823A: Tiled Swift observations
- GRB 190823A: MAXI/GSC detection
- Fermi GBM-190816: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190814bv: Coverage and upper limits from MAXI/GSC observations
- IPN triangulation of GRB 190805B
- LIGO/Virgo S190808ae: Coverage and upper limits from MAXI/GSC observations
- GRB 190805B: AstroSat CZTI detection
- GRB 190804B: Swift-XRT afterglow detection
- Konus-Wind observation of GRB 190805B
- GRB 190805B: Swift-XRT observations
- GRB 190805B: Fermi GBM detection
- GRB 190805B: Tiled Swift observations
- GRB 190804B: Swift-XRT observations
- GRB 190805B: MAXI/GSC detection
- MAXI GRB190804.33 Global MASTER-Net observations report
- GRB 190804B: Tiled Swift observations
- GRB 190804B: MAXI/GSC detection
- LIGO/Virgo S190728q: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190727h: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190720a: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190718y: Coverage and upper limits from MAXI/GSC observations
- GRB 190714A: an X-ray flare from 2E 1624.6+1504/UCAC4 525-061488
- GRB 190708B: confirmation of the X-ray afterglow
- GRB 190714A: Tiled Swift observations
- GRB 190714A: MAXI/GSC detection
- GRB 190708B: Swift-XRT observations
- Konus-Wind observation of GRB 190708B
- GRB 190708B: Tiled Swift observations
- MAXI GRB190708.83 Global MASTER-Net observations report
- GRB 190708B: MAXI/GSC detection
- LIGO/Virgo S190707q: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190706ai: Coverage and upper limits from MAXI/GSC observations
- GRB 190706A: MAXI/GSC detection
- LIGO/Virgo S190701ah: Coverage and upper limits from MAXI/GSC observations
- GRB 190701A: MAXI/GSC detection
- LIGO/Virgo S190630ag: Coverage and upper limits from MAXI/GSC observations
- IceCube Alert 190629.81 Global MASTER-Net observations report
- LIGO/Virgo S190602aq: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190521r: Coverage and upper limits from MAXI/GSC observations
- IGO/Virgo S190521g: Coverage and upper limits from MAXI/GSC observations