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"
788 results found.
- Konus-Wind detection of GRB 220310A
- GRB 220310A: GIT confirmation of optical afterglow.
- GRB 220310A: MASTER optical counterpart detection
- GRB 220310A: Swift ToO observations
- GRB 220310A: CALET Gamma-Ray Burst Monitor detection
- GRB 220310A: MAXI/GSC detection
- MAXI GRB220310.02: Global MASTER-Net observations report
- GRB 211227A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
- GRB 211227A: Deep early CAHA 2.2m/CAFOS observation
- GRB 211227A: CALET Gamma-Ray Burst Monitor detection
- GRB 211227A: MAXI/GSC detection
- GRB 211225A: MITSuME Akeno optical upper limits
- MAXI GRB211225.14: Global MASTER-Net observations report
- GRB 211225A/MAXI J0827-071: MAXI/GSC detection
- GRB 211218A: MITSuME Akeno optical upper limits
- GRB 211218A, MAXI J0909-041: MAXI/GSC detection
- MAXI GRB211218.04: Global MASTER-Net observations report
- GRB 211115A: CALET Gamma-Ray Burst Monitor detection
- GRB 211115A: MAXI/GSC detection
- MAXI GRB210709.93: Global MASTER-Net observations report
- Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
- GRB 210607A/MAXI J1733-222: MAXI/GSC detection
- MAXI GRB210607.82: Global MASTER-Net observations report
- Konus-Wind detection of GRB 210602A
- MAXI GRB210602.50: Global MASTER-Net observations report
- GRB 210602A: CALET Gamma-Ray Burst Monitor detection
- GRB 210602A: MAXI/GSC detection
- GRB 210528B: DDOTI Upper Limits on the Afterglow
- MAXI GRB210528.95: Global MASTER-Net observations report
- GRB 210528B: MAXI/GSC detection
- MAXI GRB210521.54: Global MASTER-Net observations report
- GRB 210521A: MAXI/GSC detection
- Swift Detection of MAXI J1803-298 including an optical counterpart
- MAXI GRB210501.83: Global MASTER-Net observations report
- MAXI GRB210320.89: Global MASTER-Net observations report
- GRB 210320A: MAXI/GSC detection
- Konus-Wind detection of GRB 210222A
- GRB 210222A: CALET Gamma-Ray Burst Monitor detection
- GRB 210222A: MAXI/GSC detection
- SGR 1935+2154: MAXI/GSC detection
- NuEm-210111A: MAXI/GSC upper limit
- MAXI GRB210110.64: Global MASTER-Net observations report
- GRB 210110A: MAXI/GSC detection
- GRB 210109A: MAXI/GSC detection
- GRB 210102B: further Swift-XRT observations
- GRB 210102B: Assy optical afterglow identification
- GRB 210102B: Tiled Swift observations
- GRB 210102B: Assy optical observations
- GRB 210102B: Swift-XRT observations
- MAXI GRB210102.38: Global MASTER-Net observations report
- GRB 210102B: Tiled Swift observations
- GRB 210102B: MAXI/GSC detection
- IceCube-201209A : MAXI/GSC upper limit
- MAXI GRB201021.68: Global MASTER-Net observations report
- GRB 201021B MAXI/GSC detection
- GRB 200903D: MAXI/GSC detection
- GRB 200809B: Fermi GBM detection
- GRB 200809B: Swift-XRT afterglow detection
- GRB 200809B: MAXI/GSC detection
- GRB 200615B: CALET Gamma-Ray Burst Monitor detection
- GRB 200615B: MAXI/GSC detection
- GRB 200517A: Swift-XRT Confirmation of afterglow
- 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 S200114f: No transients found in J-GEM observations of nearby galaxies
- 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