Isonoe (pron.: // 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.
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°.
- IAUC 7555: Satellites of Jupiter 2001 January 5 (discovery)
- MPEC 2001-A28: S/2000 J 2, S/2000 J 3, S/2000 J 4, S/2000 J 5, S/2000 J 6 2001 January 5 (discovery and ephemeris)
- IAUC 7998: Satellites of Jupiter 2002 October 22 (naming the moon)