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