, provisional designation , is a stony, sub-kilometer sized asteroid and fast rotator, classified as a

near-Earth object A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...

and

potentially hazardous asteroid A potentially hazardous object (PHO) is a near-Earth object – either an asteroid or a comet – with an orbit that can make close approaches to the Earth and is large enough to cause significant regional damage in the event of impact. They are ...

of the Apollo group. It had been one of the objects with the highest impact threat on the

Palermo Technical Impact Hazard Scale The Palermo Technical Impact Hazard Scale is a logarithmic scale used by astronomers to rate the potential hazard of impact of a near-Earth object (NEO). It combines two types of data—probability of impact and estimated kinetic yield— ...

Discovery

It was discovered on 24 January 2011, by a team of astronomers at

Pan-STARRS 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 ...

, the ''Panoramic Survey Telescope and Rapid Response System'' at Haleakala Observatory on Hawaii, United States. The discovery was made using a 1.8-meter Ritchey–Chrétien telescope. At the time of discovery, the object had 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.

Orbit

Before the 2013 recovery it had an observation arc of 41 days with an

uncertainty parameter The uncertainty parameter ''U'' is introduced by the Minor Planet Center (MPC) to quantify the uncertainty of a perturbed orbital solution for a minor planet. The parameter is a logarithmic scale from 0 to 9 that measures the anticipated longit ...

of 7. Due to precovery images from 2007 it now has an observation arc of more than 5 years. It makes close approaches to Earth and Mars. On 28 December 2013, it passed from Earth. The December 2013 passage was studied by the Goldstone Deep Space Network and further refined the orbit.

Impact risk

While listed on the Sentry Risk Table, virtual clones of the asteroid that fit the uncertainty region in the known trajectory showed a 1 in 71,000 chance that the asteroid could

impact Impact may refer to: * Impact (mechanics), a high force or shock (mechanics) over a short time period * Impact, Texas, a town in Taylor County, Texas, US Science and technology * Impact crater, a meteor crater caused by an impact event * Impac ...

Earth on 5 January 2080. In 2013 it had the 5th highest impact threat on the

. It was removed from the

Sentry Risk Table Sentry is a highly automated impact prediction system operated by the JPL Center for NEO Studies (CNEOS) since 2002. It continually monitors the most up-to-date asteroid catalog for possibilities of future impact with Earth over the next 100+ y ...

on 17 June 2013. With a 2080 Palermo Technical Scale of −3.58, the odds of impact by in 2080 were about 3800 times less than the background hazard level of Earth impacts which is defined as the average risk posed by objects of the same size or larger over the years until the date of the potential impact.

JPL Horizons JPL Horizons On-Line Ephemeris System provides access to key Solar System data and flexible production of highly accurate ephemerides for Solar System objects. Osculating elements at a given epoch (such as produced by the JPL Small-Body Databas ...

shows that the

nominal Nominal may refer to: Linguistics and grammar * Nominal (linguistics), one of the parts of speech * Nominal, the adjectival form of "noun", as in "nominal agreement" (= "noun agreement") * Nominal sentence, a sentence without a finite verb * Nou ...

pass will be on 17 January 2080 at a distance of from Earth.

Physical characteristics

This near-Earth object is characterized as a common, stony

S-type asteroid S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the secon ...

by the ''Collaborative Asteroid Lightcurve Link'' (CALL).

Fast rotator

In January 2014, a rotational

lightcurve In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular freq ...

of was obtained from photometric observations by American astronomer Brian Warner at the CS3-Palmer Divide Station () in California. Lightcurve analysis gave a well-defined rotation period of 0.109138 hours (393 seconds) with a brightness amplitude of 0.61

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

().

Diameter and albedo

According to the CALL and JPL's impact-risk table, this near-Earth object measures 136 and 150 meters, respectively. For its size estimate, CALL uses a standard for stony asteroids of 0.20 with an

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it ...

of 21.7.

Naming

As of 2017, this

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''mino ...

remains unnamed.

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend * * * {{DEFAULTSORT:2011 BT15 471240 471240 471240 471240 471240 471240 20110124