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"
844 results found.
- MAXI GRB200205.29: Global MASTER-Net observations report
- LIGO/Virgo S200129m: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200128d: No counterpart candidates in KAIT observations
- LIGO/Virgo S200128d: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200114f: Upper Limits from Wide-Field Infrared Search with Palomar Gattini-IR
- 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
- LIGO/Virgo S191105e: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190930s: No counterpart candidates in KAIT observations
- 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 S190923y: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190910d and S190910h: No counterpart candidates in KAIT 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: No counterpart candidates in KAIT observations
- LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190828l: No counterpart candidates in KAIT observations
- GRB 190828A: Swift-XRT observations
- LIGO/Virgo S190828j: No counterpart candidates in KAIT 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 : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
- LIGO/Virgo S190814bv : No Counterpart Candidates in Galaxy Targeted Search with Magellan
- LIGO/Virgo S190814bv: No counterpart candidates in KAIT 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: No counterpart candidates in KAIT observations
- LIGO/Virgo S190728q: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190727h: No counterpart candidates in KAIT observations
- LIGO/Virgo S190727h: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190720a: No counterpart candidates in KAIT observations
- LIGO/Virgo S190720a: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190718y: No counterpart candidates in KAIT 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 S190706ai: No counterpart candidates in KAIT observations
- 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 S190630ag: No counterpart candidates in KAIT observation
- 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
- 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
- LIGO/Virgo S190519bj: MAXI/GSC Observations
- LIGO/Virgo S190517h: MAXI/GSC Observations
- LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
- LIGO/Virgo S190513bm: MAXI/GSC Observations
- LIGO/Virgo S190512at: MAXI/GSC Observations
- LIGO/Virgo S190510g: Las Cumbres Observatory Galaxy Targeted Counterpart Search
- LIGO/Virgo S190510g: Lick/KAIT Follow-Up Observations
- LIGO/Virgo S190510g: Potential host galaxies on the updated skymap from the GLADE catalog
- LIGO/Virgo S190510g: MAXI/GSC Observations
- LIGO/Virgo S190510g: Potential host galaxies from the GLADE catalog
- IceCube-190504A: MASTER optical monitoring analysis