(15789) 1993 SC is a

trans-Neptunian object A trans-Neptunian object (TNO), also written transneptunian object, is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune, which has an orbital semi-major axis of 30.1 astronomical units (AU). ...

of the

plutino In astronomy, the plutinos are a dynamical group of trans-Neptunian objects that orbit in 2:3 mean-motion resonance with Neptune. This means that for every two orbits a plutino makes, Neptune orbits three times. The dwarf planet Pluto is the la ...

class. The discovery was made in 1993 at the

La Palma La Palma (, ), also known as ''La isla bonita'' () and historically San Miguel de La Palma, is the most northwesterly island of the Canary Islands, a Spanish autonomous community and archipelago in Macaronesia in the North Atlantic Ocean. La Pa ...

Observatory with the

Isaac Newton Telescope The Isaac Newton Telescope or INT is a 2.54 m (100 in) optical telescope run by the Isaac Newton Group of Telescopes at Roque de los Muchachos Observatory on La Palma in the Canary Islands since 1984. Originally the INT was situated at He ...

. The object measures approximately 328 km in diameter. It was the second plutino to receive an MPC

number A number is a mathematical object used to count, measure, and label. The most basic examples are the natural numbers 1, 2, 3, 4, and so forth. Numbers can be represented in language with number words. More universally, individual numbers can ...

. Other Kuiper belt objects discovered in 1993 include:

(15788) 1993 SB (15788) 1993 SB is a trans-Neptunian object of the plutino class. Apart from Pluto, it was one of the first such objects discovered (beaten by two days by (385185) 1993 RO and by one day by 1993 RP), and the first to have an orbit calculated well ...

, (15789) 1993 SC,

(181708) 1993 FW (181708) 1993 FW (Minor planet provisional designation, provisional designation ) is a cubewano and was the second trans-Neptunian object to be discovered after Pluto and Charon (moon), Charon, the first having been 15760 Albion, formerly known as ...

(385185) 1993 RO (385185) 1993 RO is a plutino. It was the first plutino discovered after Pluto itself, with 1993 RP and (15788) 1993 SB a day and two days later, respectively. The discovery was made in 1993 at the Mauna Kea Observatory with a 2.2-meter telesco ...

and 1993 RP.

Orbit and classification

1993 SC orbits the Sun at a distance of 32.2-46.1 AU one per 247 Earth years (90,254 days,

semi-major axis In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the longe ...

of 39.4 AU). Its orbit has an eccentricity of 0.183 and an inclination of 5.166° respective to the

elliptic In mathematics, an ellipse is a plane curve surrounding two focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant. It generalizes a circle, which is the special type of ellipse in ...

. Its

observation arc In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly use ...

begins with Mauna Kea Observatory in 1993. 1993 SC is a

and belongs to the

s, an orbital class of objects named after their largest member,

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of Trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Su ...

. These

resonant trans-Neptunian object In astronomy, a resonant trans-Neptunian object is a trans-Neptunian object (TNO) in mean-motion orbital resonance with Neptune. The orbital periods of the resonant objects are in a simple integer relations with the period of Neptune, e.g. 1:2, 2 ...

s stay in a 2:3 mean-motion

orbital resonance In celestial mechanics, orbital resonance occurs when orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers. Most commonly, this relation ...

with

Neptune Neptune is the eighth and farthest known planet from the Sun. It is the List of Solar System objects by size, fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 t ...

, orbiting exactly two times the sun for every three orbits Neptune does.

Numbering and naming

1993 SC was numbered by the

Minor Planet Center The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Funct ...

on 26 July 2000, receiving the number in the minor planet catalog. As of 2018, it has not been named. According to the established

naming conventions A naming convention is a convention (norm), convention (generally agreed scheme) for naming things. Conventions differ in their intents, which may include to: * Allow useful information to be deduced from the names based on regularities. For ins ...

, it will get a mythological name associated with the underworld.

Physical characteristics

1993 SC has a diameter of and a low

geometric albedo In astronomy, the geometric albedo of a celestial body is the ratio of its actual brightness as seen from the light source (i.e. at zero phase angle (astronomy), phase angle) to that of an ''idealized'' flat, fully reflecting, diffuse reflection, d ...

of 0.022. It also has a very red surface color ( RR) in its visible spectrum, with B-V and V-R color indices of and respectively. A red surface color is typically represented with the association of

tholin Tholins (after the Greek (') "hazy" or "muddy"; from the ancient Greek word meaning "sepia ink") are a wide variety of organic compounds formed by solar ultraviolet or cosmic rays, cosmic ray irradiation of simple carbon-containing compounds su ...

s, polymer-like organic compounds, formed by long exposures to solar and cosmic radiation.

References

External links

MPC: List of TNOs
* Grundy, W. M.; Noll, K. S.; Stephens, D. C. "Diverse albedos of small trans-neptunian objects." Icarus, Volume 176, Issue 1, p. 184-191 (07/2005
Abstract
* {{DEFAULTSORT:015789 Plutinos 19930917 1993 SC 1993 SC 1993 SC

Orbit and classification

Numbering and naming

Physical characteristics

See also

References

External links