(84922) 2003 VS2

(84922) 2003 VS₂ is a trans-Neptunian object discovered by the Near-Earth Asteroid Tracking program on 14 November 2003.^[1] Like Pluto, it is in a 2:3 orbital resonance with Neptune^[3][4] and is thus a plutino. It has an elongated ellipsoidal shape.^[5]

(84922) 2003 VS₂

Hubble Space Telescope image of 2003 VS2 taken in 2005
Discovery[1]
Discovered by	NEAT (644)
Discovery date	14 November 2003[2]
Designations
MPC designation	(84922) 2003 VS2
Alternative designations	none
Minor planet category	Plutino[3][4]
Orbital characteristics[2][3]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 3
Observation arc	8830 days (24.18 yr)
Earliest precovery date	17 September 1991
Aphelion	42.413 AU (6.3449 Tm)
Perihelion	36.456 AU (5.4537 Tm)
Semi-major axis	39.435 AU (5.8994 Tm)
Eccentricity	0.075539
Orbital period (sidereal)	247.64 yr (90451.3 d)
Average orbital speed	4.75 km/s
Mean anomaly	15.535°
Mean motion	0° 0m 14.328s / day
Inclination	14.777°
Longitude of ascending node	302.792°
Argument of perihelion	114.317°
Physical characteristics
Dimensions	(678±10) × (470±12) × (452±16) km[5]
Mean diameter	524±7 km[5] 548.3+29.5 −44.6 km[6] 523.0+35.1 −34.4 km[7]
Mean density	1.4+1.0 −0.3 g/cm3[6]
Synodic rotation period	7.4175285±0.00001 h[8]
Sidereal rotation period	7.41±0.02 h[9]
Geometric albedo	0.134±0.01[5]
Temperature	≈44 K
Spectral type	(moderately red) B−V = 0.93±0.02 V−R = 0.59±0.02[7]
Apparent magnitude	19.7[10]
Absolute magnitude (H)	4.11±0.38[8]

Orbit and rotation

Like Pluto, (84922) 2003 VS₂ is locked in the 3:2 mean-motion resonance with Neptune, although its orbit is both less inclined and significantly less eccentric than Pluto's.^[2]

(84922) 2003 VS₂ has a high light curve amplitude of 0.21±0.01, indicative of an elongated, non-spherical shape.^[5] The most likely value of the rotation period is 7.41±0.02 h.^[9]

Physical characteristics

(84922) 2003 VS₂ has a moderately red surface with a moderately red color indices B−V=0.93, V−R=0.59.^[11] Its geometrical albedo is about 0.13.^[6]

In 2007, its diameter was initially estimated by the Spitzer Space Telescope at 725±200 km.^[12] However, in 2012, this was reduced to 523.0+35.1
−34.4 km after new Herschel Space Telescope observations.^[7] In 2019, 2003 VS₂ was found to be ellipsoidal in shape based on stellar occultations that occurred in 2013 and 2014;^[6] the light curve derived from the occultations suggests that this plutino is not in hydrostatic equilibrium and hence not a dwarf planet.^[13] The dimensions of 2003 VS₂ are estimated at 627.6 km × 531 km × 494.6 km, with a volume-equivalent diameter 548.3+29.5
−44.6 km.^[6] 2003 VS₂ has no known satellite that can be used to directly determine its mass, but assuming a density of 1 g/cm³, typical of mid size TNO's,^[14] gives a mass estimate of about 7.5×10¹⁹ kg.

2003 VS₂ (apparent magnitude 19.8) as viewed with a 24" telescope

See also

• Sedna, another large trans-Neptunian object, a dwarf planet, discovered the same day (14 November 2003)