noun, plural jan·skies.
- a unit of flux density for electromagnetic radiation, used chiefly in radio astronomy. Abbreviation: Jy
- Karl Guthe,1905–50, U.S. engineer: pioneer in radio astronomy.
noun plural -skys
- a unit of flux density equal to 10 –26 W m –2 Hz –1, used predominantly in radio and infrared astronomySymbol: Jy
- Karl Guthe 1905–50, US electrical engineer. He discovered a source of radio waves outside the solar system (1932) and pioneered radio astronomy