(15788) 1993 SB 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. Apart from

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 ...

, it was one of the first such objects discovered (beaten by two days by

(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 by one day by 1993 RP), and the first to have an orbit calculated well enough to receive a

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 ...

. 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 ...

. Very little is known about the object. Even the diameter estimate of ~130 km is based on an assumed

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

of 0.09. Other Kuiper belt objects discovered in 1993 include: (15788) 1993 SB,

(15789) 1993 SC (15789) 1993 SC is a trans-Neptunian object of the plutino class. The discovery was made in 1993 at the La Palma Observatory with the Isaac Newton Telescope. The object measures approximately 328 km in diameter. It was the second plutino to rece ...

(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 ...

, and

. Over one thousand bodies were found in a belt between orbiting between about 30-50 AU from the Sun in the twenty years (1992-2012), after finding 1992 QB1 (named in 2018, 15760 Albion), showing a vast belt of bodies more than just Pluto and Albion. By 2018, over 2000 Kuiper belt objects were discovered.

References

External links

MPEC: recovery of the object

* Plutinos 1993 SB 1993 SB 1993 SB 19930916 {{CentaurTNO-stub