1995 GJ might be 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 ...

and/or high-inclination

cubewano A classical Kuiper belt object, also called a cubewano ( "QB1-o"), is a low-eccentricity Kuiper belt object (KBO) that orbits beyond Neptune and is not controlled by an orbital resonance with Neptune. Cubewanos have orbits with semi-major a ...

from the Kuiper belt in the outermost region of the

Solar System The Solar System Capitalization 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 ...

, and based on the calculated distance and brightness is assumed to be approximately in diameter. It is 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 ...

that has only been observed six times on the nights of 3–4 April 1995, by

David Jewitt David Clifford Jewitt (born 1958) is a British-American astronomer who studies the Solar System, especially its minor bodies. He is based at the University of California, Los Angeles, where he is a Member of the Institute for Geophysics and Pl ...

and Jun Chen at the

Mauna Kea Observatory The Mauna Kea Observatories (MKO) are a group of independent astronomical research facilities and large telescope observatories that are located at the summit of Mauna Kea on the Big Island of Hawaiʻi, United States. The facilities are locate ...

, Hawaii, using the

UH88 The University of Hawai'i 88-inch (2.24-meter) telescope—called UH88, UH2.2, or simply 88 by members of the local astronomical community—is situated at the Mauna Kea Observatories and operated by the University's Institute for Astronomy. It ...

telescope, and has not been observed ever since. The object is estimated to have been discovered right at

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 ...

(closest approach to the Sun) at a distance of from the Sun. On the night of discovery, the object is estimated to have been moving away from Earth at with the uncertainty in the velocity being an unrealistic (80% the

speed of light The speed of light in vacuum, commonly denoted , is a universal physical constant that is important in many areas of physics. The speed of light is exactly equal to ). According to the special theory of relativity, is the upper limit ...

Orbit

The nominal orbit of 1995 GJ suggests it orbits the Sun at a distance of 39–46 AU once every 281 years with an assumed

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 0.09 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 23 ° 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 ...

. But 1995 GJ has the highest possible orbital uncertainty and thus very large uncertainties in the orbital elements. With only a 1-day

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 ...

, the orbit is so poorly constrained as to be almost worthless. The eccentricity is listed as , even though realistically it will be less than 1. Otherwise known for their low inclinations, this cubewano may be the first of its kind to have an inclination greater than 20 °. But as a one-night stand with only 6 observations, 1995 GJ has numerous orbits that fit the uncertainties in the very small dataset. 1995 GJ could be a trans-Neptunian object, a centaur, or a much closer

main belt The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...

asteroid 100 times smaller in diameter. As an example, (when it had a one-day observation arc) was thought to be a potential trans-Neptunian dwarf planet, but is now known to be a small main belt asteroid. Using the nominal orbit with the assumed

, 1995 GJ may come to

opposition Opposition may refer to: Arts and media * ''Opposition'' (Altars EP), 2011 EP by Christian metalcore band Altars * The Opposition (band), a London post-punk band * '' The Opposition with Jordan Klepper'', a late-night television series on Com ...

around mid March of each year at an

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's ...

of 22.9. , the uncertainty in the object's distance from the Sun is an unrealistic ±.

References

External links

List Of Transneptunian Objects
Minor Planet Center * {{DEFAULTSORT:1995 GJ Kuiper belt objects Minor planet object articles (unnumbered) Lost minor planets 19950403