Discovered by Nichole M. Danzl MPC designation (26308) 1998 SM165 Minor planet category twotino
Kozai Orbital period 328 years Inclination 13.5226° Orbits Sun | Discovery date 16 September 1998 Alternative names none Observation arc 9952 days (27.25 yr) Discovered 16 September 1998 Argument of perihelion 130.56° Discoverer Nichole M. Danzl | |
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Discovery site Kitt Peak National Observatory | ||
26308 1998 sm165
(26308) 1998 SM165, also written as (26308) 1998 SM165, is a binary trans-Neptunian object (TNO) that resides in the Kuiper belt. It was discovered on September 16, 1998, by Nichole Danzl. It is in a 1:2 orbital resonance with the planet Neptune.
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Twotino
1998 SM165 has a semi-major axis (average distance from the Sun) near the edge of the classical belt. Both the Minor Planet Center (MPC) and the Deep Ecliptic Survey (DES) list this trans-Neptunian object as a twotino. For every one orbit that a twotino makes, Neptune orbits twice.
Physical characteristics
The observations with the infrared Spitzer Space Telescope combined with the orbits established using the Hubble Telescope allow the estimation of the density, assuming the components of equal albedo.
The resulting estimate of 7002510000000000000♠0.51+0.29
−0.14 g/cm3 is similar to the density of the binary plutino (47171) 1999 TC36 (0.3–0.8 g/cm3) and Saturn’s moon Hyperion (7002567000000000000♠0.567±0.102 g/cm3) Such a low density is indicative of a highly porous composition dominated by ice.
(26308) 1998 SM165 is fairly red, with a color comparable to 79360 Sila–Nunam.
Satellite
Designated S/2001 (26308) 1, it is about 96 ± 12 km (59.7 ± 7.5 mi) in diameter and it orbits its primary at a distance of 11,310 ± 110 km (7,028 ± 68 mi). Assuming a circular orbit, this takes 7002130100000000000♠130.1±1 days to complete one orbit.