Tinia (moon)
 Hubble Space Telescope image of 55637 Uni and its moon Tinia at 10 o'clock. | |
| Discovery | |
|---|---|
| Discovered by | Brown et al. |
| Discovery date | August 2005 |
| Designations | |
Designation | (55637) Uni I |
| Pronunciation | /ˈtɪniə/ |
Named after | Tinia |
| Orbital characteristics | |
| 4750±40 km[1] | |
| Eccentricity | 0.17±0.03[2] |
| 8.3095 d (prograde)[1] | |
| Inclination | 63.1°[1] |
| Satellite of | 55637 Uni |
| Physical characteristics | |
| 105±15 km[3] | |
| Uni + 2.5[4] | |
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.[4] 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.[5]
Physical characteristics
Tinia was discovered at 0.16 arcseconds from Uni with a difference in absolute magnitude of 2.5[4][6] Its diameter is estimated at 210±30 km. Assuming an albedo similar to its primary, Tinia should have a diameter of approximately 190 km;[2] assuming an albedo of 0.05, typical of cool classical KBOs of similar size, it should have a diameter of approximately 260 km.[7]
Orbital characteristics
Tinia completes one complete orbit around Uni every 8.309±0.0002 days, at a distance of 4770±40 km, indicating a total system mass of (1.25±0.03)×1020 kg.[7][2] Its orbital eccentricity is 0.17±0.03.[2]
References
- ^ a b c "2002 UX25 System parameters". Will Grundy. Retrieved 2023-08-29.
- ^ a b c d "(55637) Uni and Tinia". www.johnstonsarchive.net. Retrieved 2025-09-06.
- ^ "(55637) 2002 UX25". Retrieved 28 July 2023.
- ^ a b c "IAUC 8812: Satellites of 2003 AZ_84, (50000), (55637), (90482); V1281 Sco; V1280 Sco". www.cbat.eps.harvard.edu. Retrieved 2025-09-06.
- ^ "WGSBN Bulletin (Vol. 5, No. 20)" (PDF). IAU. 2025-09-01. p. 6.
- ^ "Αρχειοθετημένο αντίγραφο". Archived from the original on 2007-09-12. Retrieved 2018-10-06.
- ^ a b M.E. Brown (2013). "The density of mid-sized Kuiper belt object 2002 UX25 and the formation of the dwarf planets". The Astrophysical Journal Letters. 778 (2): L34. arXiv:1311.0553. Bibcode:2013ApJ...778L..34B. doi:10.1088/2041-8205/778/2/L34. S2CID 17839077.