Astronomy:(612620) 2003 SQ317

(612620) 2003 SQ₃₁₇

Hubble Space Telescope image of 2003 SQ317 taken in 2009
Discovery
Discovered by	CFEPS
Discovery site	Mauna Kea Obs.
Discovery date	23 September 2003 (first observed only)
Designations
MPC designation	2003 SQ317
Minor planet category	TNO · cubewano SCATEXTD
Orbital characteristics
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 4
Observation arc	10.12 yr (3,698 days)
|{{{apsis}}}|helion}}	45.746 AU
|{{{apsis}}}|helion}}	39.231 AU
Semi-major axis	42.489 AU
Eccentricity	0.0767
Orbital period	276.96 yr (101,159 days)
Mean anomaly	6.9467°
Mean motion	0° 0m 12.96s / day
Inclination	28.619°
Longitude of ascending node	176.34°
|{{{apsis}}}|helion}}	191.81°
Physical characteristics
Dimensions	300±150 km
Mean density	0.8–2.7 g/cm3
Rotation period	7.210±0.001 h 7.5 h
Geometric albedo	0.05–0.50
Spectral type	B−R=1.05±0.18
Absolute magnitude (H)	6.2

(612620) 2003 SQ₃₁₇ is a classical trans-Neptunian object and member of Haumea family from the Kuiper belt located in the outermost regions of the Solar System, approximately 300 kilometers in diameter. It was first observed on 23 September 2003, by astronomers of the Canada–France Ecliptic Plane Survey at Mauna Kea Observatories on Hawaii. The surface of 2003 SQ₃₁₇ is made of water ice.

Physical properties

The orbits of multiple objects in the Haumea family. 2003 SQ₃₁₇ is not shown in the diagram, though its orbit is similar to that of other objects in the Haumea family.

2003 SQ₃₁₇ is a classical Kuiper belt object (cubewano) belonging to the hot population. Its size estimated to lie between 150 and 450 km based on a range of plausible albedos. The object has a large light curve amplitude of about 0.85, which indicates that it has an extremely elongated shape or is a contact binary. In the former case the density of 2003 SQ₃₁₇ is estimated at 0.86 g/cm³ and its axis ratios at 0.55 and 0.41. If 2003 SQ₃₁₇ is a contact binary, which is actually more likely, the density is estimated at 2.67 g/cm³. In the latter case, the components are also thought to be unequal in size with the mass ratio of about 0.3 and axis ratios of about 0.8 and 0.5, respectively, for the primary and secondary components.

Origin

2003 SQ₃₁₇ was identified as a member of the Haumea family, which is defined based on a common pattern of IR water-ice absorption, neutral visible spectrum and the clustering of the orbital elements. The Haumea family members including (19308) 1996 TO66, (55636) 2002 TX300, (120178) 2003 OP32, (145453) 2005 RR43 and others all appear to be collisional fragments broken off of the dwarf planet Haumea.

See also

• (139775) 2001 QG298
• 2004 TT357

External links

• (612620) 2003 SQ317 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters