Jansky:
The Jansky (Jy) is defined as:
1 . 10-26 Watts / Hz . m2
Incidentally, my first guess was that it is a synonym for jargon. Not. Even. Close. Noted in “Ronnametres and quettagrams have joined the ranks of SI units,” Alex Wilkins, NewScientist (26 November 2022):
[Richard Brown at the National Physical Laboratory] suggests that ronto and quecto could have uses in radio astronomy, such as for measuring the very weak strength of the cosmic microwave background, radiation left over from the big bang, but astronomers already frequently use the non-SI jansky for this, says [Mike Merrifield at the University of Nottingham].
