Isonoe ( /aɪˈsɒnɵʊiː/ eye-SON-o-ee; Greek: Ισονόη), also known as Jupiter XXVI, is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2000, and given the temporary designation S/2000 J 6.
Isonoe is about 3.8 kilometres in diameter, and orbits Jupiter at an average distance of 23,833 Mm in 751.647 days, at an inclination of 166° to the ecliptic (169° to Jupiter's equator), in a retrograde direction and with an eccentricity of 0.166.
It was named in October 2002 after Isonoe, one of the Danaides in Greek mythology, and a lover of Zeus (Jupiter).
Isonoe belongs to the Carme group, made up of irregular retrograde moons orbiting Jupiter at a distance ranging between 23 and 24 Gm and at an inclination of about 165°.