Tinia (moon)

Tinia is the only known moon of the trans-Neptunian object 55637 Uni.

Discovery and naming

Tinia was discovered in August 2005, by observations with the Hubble Space Telescope, and announced on 22 February 2007.
It was named together with Uni on 1 September 2025 after Tinia, the Etruscan sky god and husband of the Etruscan goddess of love and fertility Uni.

Physical characteristics

Tinia was discovered at 0.16 arcseconds from Uni with a difference in absolute magnitude of 2.5 Its diameter is estimated at. Assuming an albedo similar to its primary, Tinia should have a diameter of approximately 190 km; assuming an albedo of 0.05, typical of cool classical KBOs of similar size, it should have a diameter of approximately 260 km.

Orbital characteristics

Tinia completes one complete orbit around Uni every days, at a distance of, indicating a total system mass of. Its orbital eccentricity is.