, also written as 1995 SN55, is a lost centaur with a perihelion

Apsis

An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...

 greater than Jupiter

Jupiter

Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

 and a semi-major axis

Semi-major axis

The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape...

 that may be less than Neptune

Neptune

Neptune is the eighth and farthest planet from the Sun in the Solar System. Named for the Roman god of the sea, it is the fourth-largest planet by diameter and the third largest by mass. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times...

's. This object could be the largest known centaur.

Size

If is confirmed to have the orbit of a centaur, it will be one of the largest centaurs known. Centaurs typically have an albedo of about 0.07. With an absolute magnitude

Absolute magnitude

Absolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth...

 (H) of 6.0, and using an average centaur albedo of 0.07, could be 310 km in diameter. The two largest known centaurs are 10199 Chariklo

10199 Chariklo

10199 Chariklo is the largest known centaur. It orbits the Sun between Saturn and Uranus, grazing Uranus.Chariklo was discovered by James V. Scotti of the Spacewatch program on February 15, 1997. Chariklo is named after the nymph Chariclo , the wife of Chiron and the daughter of Apollo.A...

 (260 km / H=6.4 / albedo = 0.05) and 2060 Chiron

2060 Chiron

2060 Chiron is a minor planet in the outer Solar System. Discovered in 1977 by Charles T. Kowal , it was the first-known member of a new class of objects now known as centaurs, with an orbit between Saturn and Uranus.Although it was initially classified as an asteroid, it was later found to...

 (230 km / H=6.5 / albedo = 0.07).

Lost

was only observed 14 times over 36 days from September 20, 1995 until October 26, 1995. Due to this short observation arc, the object has a very poorly known orbit and is considered lost. (See Lost comet

Lost comet

A lost comet is a previously discovered comet that has been missed at its most recent perihelion passage, generally because there is not enough data to reliably calculate the comet's orbit and predict its location....

 or Lost asteroid.)

JPL

Jet Propulsion Laboratory

Jet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena on the border of La Cañada Flintridge and Pasadena...

 shows this object having an aphelion

Apsis

An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...

 distance of only 39.1 AU, while the Deep Ecliptic Survey

Deep Ecliptic Survey

The Deep Ecliptic Survey is a project to find Kuiper belt objects , using the facilities of the National Optical Astronomy Observatory .The principal investigator is Bob Millis....

(DES) shows it having an aphelion distance of 91 AU.

External links

• Orbital simulation from JPL (Java) / Ephemeris