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EntityQ603083· pop 30· linked from 486 articles

Also known as (90482) Orcus I Vanth, Orcus I, S/2005 (90482) 1

natural satellite orbiting 90482 Orcus

Key facts

Discovered by
Michael E. Brown Terry-Ann Suer
Discovery date
13 November 2005
Designation
(90482) Orcus I
Pronunciation
/ ˈ v æ n θ /
Named after
Vanth
Adjectives
Vanthian
Semi major axis
8 999 .8 ± 9.1 km
Eccentricity
0.000 91 ± 0.000 53
Orbital period sidereal
9.539 154 ± 0.000 020 d
Inclination
105.03 ° ± 0.18 ° (to celestial equator ), 90.54° ± 0.17° (to ecliptic )
Longitude of ascending node
53.49° ± 0.33°
Argument of periapsis
274.51°
Satellite of
Orcus
Mean diameter
442.5 ± 10.2 km ( occultation ) , 475 ± 75 km ( thermal )
Mass
(8.7 ± 0.8) × 10 kg
Mean density
≈1.9 ± 0.3 g/cm (occultation) , 1.5 +1.0, −0.5 g/cm (thermal)
Synodic rotation period
synchronous
Albedo
0.08 ± 0.02

via Wikipedia infobox

Wikidata facts

Diameter
442.5
Mass
87
Orbital period
9.539154
Image
Orcus-vanth hst2.jpg
Show 11 more facts
time of discovery or invention
2005-11-13
provisional designation
S/2005 (90482) 1
absolute magnitude
4.88
semi-major axis of an orbit
8999.8
apparent magnitude
21.8
orbital eccentricity
0.00091
orbital inclination
105.03
albedo
0.08
density
1.5
color index
1.03
longitude of ascending node
53.49
Sources (5)

via Wikidata · CC0

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Article

Vanth (formal designation (90482) Orcus I) is the only known moon of the large trans-Neptunian dwarf planet Orcus. It was discovered by Michael Brown and Terry-Ann Suer using images taken by the Hubble Space Telescope on 13 November 2005. The moon has a diameter of 443 km (275 mi), making it about half the size of Orcus and the third-largest moon of a trans-Neptunian object.

Vanth is massive enough that it shifts the barycenter of the Orcus–Vanth system outside of Orcus, forming a binary system in which the two bodies revolve around the barycenter, much like the Pluto–Charon system. It is hypothesized that both systems formed similarly, most likely by a giant impact early in the Solar System's history. Compared to Orcus, Vanth has a darker and slightly redder surface that supposedly lacks exposed water ice, resembling primordial Kuiper belt objects.

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