(

provisional designation Provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been cal ...

) 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 a semi-major axis of 30.1 astronomical units (au). Typically ...

that orbits in the

outer Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

beyond the orbit of Neptune. First observed as by

Spacewatch The Spacewatch Project is an astronomical survey that specializes in the study of minor planets, including various types of asteroids and comets at University of Arizona telescopes on Kitt Peak near Tucson, Arizona, in the United States. The Spa ...

on 20 September 1995, it was a

lost minor planet A minor planet is "lost" when today's observers cannot find it, because its location is too uncertain to target observations. This happens if the orbital elements of a minor planet are not known accurately enough, typically because the observat ...

with an insufficiently defined orbit with only 36 days of observations. On 8 October 2010, it was rediscovered by the

Pan-STARRS 1 The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1; obs. code: F51 and Pan-STARRS2 obs. code: F52) located at Haleakala Observatory, Hawaii, US, consists of astronomical cameras, telescopes and a computing facility that is ...

survey and later announced as in July 2016. It was not until November 2020 when

amateur astronomer Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers ...

s S. Deen and K. Ly identified and as the same object. This identification was confirmed and announced by the Minor Planet Center in January 2021. Once thought to be a centaur crossing the orbits of the

gas giant A gas giant is a giant planet composed mainly of hydrogen and helium. Gas giants are also called failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System. The term "gas giant" ...

s, is now known to be a trans-Neptunian object in a 3:5

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 relationsh ...

with Neptune. With an estimated diameter between , it was formerly considered one of the largest centaurs.

Observations

First observation and loss

was near

perihelion An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elli ...

35.4 AU from the Sun when it was first observed in 1995, by astronomers Nichole Danzl and Arianna Gleason of the

survey at

Kitt Peak Observatory The Kitt Peak National Observatory (KPNO) is a United States astronomical observatory located on Kitt Peak of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono Oʼodham Nation, west-southwest of Tucson, Arizona. With more than ...

in Arizona, United States. It was only observed 14 times over 36 days, from 20 September to 26 October 1995. The discovery observations of were published and announced by the Minor Planet Center on 11 June 1999. By 2020 the 3-sigma uncertainty in the heliocentric distance to the original orbit solution for was approximately ±.

Recovery

On 30 November 2020, amateur astronomers S. Deen and K. Ly identified as the 3:5 resonant trans-Neptunian object , which was discovered by

in 2010. The identification was published by the Minor Planet Center on 27 January 2021.

Classification and orbit

orbits the Sun at an average distance of 42.33 AU once every 275 years. Its orbit has an

eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.16 and an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

of 4 ° with respect to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic agains ...

plane. Over the course of its orbit, its distance from the Sun ranges from 35.4 AU at

to 49.3 AU at

aphelion An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ell ...

. is in a 3:5 mean-motion orbital resonance with Neptune; for every three orbits it makes, Neptune orbits five times. Its orbit has a

minimum orbit intersection distance Minimum orbit intersection distance (MOID) is a measure used in astronomy to assess potential close approaches and collision risks between astronomical objects. It is defined as the distance between the closest points of the osculating orbits o ...

approximately from Neptune's orbital path.

Numbering and naming

was numbered by the Minor Planet Center on 25 September 2018 and received the number in the minor planet catalog. The alternate

was given by the Minor Planet Center on 27 January 2021 after the two objects were linked. , it has not been named.

References

External links

A 300-kilometre space rock has vanished since we saw it in 1995
Joshua Sokol, ''

New Scientist ''New Scientist'' is a magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organisation publish ...

'', 25 October 2017 * {{DEFAULTSORT:2014 OK394 523731 523731 523731 19950920 20101008