is a small, unusually spectrally red asteroid estimated to be around in size. Its orbit crosses Earth's, and is therefore classified as an Apollo asteroid and a near-Earth object (NEO). It was discovered on 9 September 2015 by the Pan-STARRS survey at the Haleakalā Observatory in Hawaii, United States, during one of its close encounters with Earth.
Discovery and observations was discovered on 9 September 2015 by the Pan-STARRS 1 telescope as the asteroid passed within 0.1907 astronomical units (AU) from Earth. Further observations were conducted to establish and refine the asteroid's orbit. These observations extended to March 2016, and once again in March 2018 , it has not yet been numbered or named by the Minor Planet Center.
passed within from Earth on 15 December 2022. This encounter permitted the Goldstone Observatory, alongside the Australia-based Canberra Deep Space Communication Complex and Australia Telescope Compact Array, to conduct radar imaging of the asteroid.
Orbit
is classified as a near-Earth object (NEO) and an Apollo asteroid (as its orbit crosses the Earth's). It has an orbital period of around 1.791 Earth years. Its orbit is moderately elliptical, with an orbital eccentricity of 0.3475. It has a semi-major axis of 1.4746 AU, with its distance from the Sun varying from 0.962 AU at perihelion to 1.987 AU at aphelion. Its orbital inclination with respect to the ecliptic plane (the orbital plane of the Earth around the Sun) is very small, at 0.2343°.
Physical characteristics The size of has not been directly measured, but it can be estimated from its brightness (absolute magnitude) and how reflective its surface is (geometric albedo). Using an absolute magnitude value of and assuming 's geometric albedo is , 's estimated diameter is .
During the December 2022 close encounter, 's lightcurve data was taken. Using the observed data, several teams of astronomers calculated its rotation period from fluctuations in the asteroid's observed brightness. Initial calculations gave a period of about , with irregularities in its lightcurve possibly indicating chaotic rotation. Later analysis in a 2023 study led by Jin Beniyama revealed an additional, shorter long period in 's lightcurve. The presence of both suggests precession, though which period corresponds to the rotation period and precession period remains unclear.
Unusually, 's visible spectrum suggests that it is strongly red. It is nearly as red as the visible spectrum of 269 Justitia, a similarly extremely red object located in the main asteroid belt. 's spectrum also agrees well with that of rare A-type asteroids and Z-type asteroids, the latter classification having been recently proposed in a 2022 study led by Max Mahlke.
Exploration serves as a potential target for a future spacecraft mission due to its proximity and unusual spectral properties. For a launch window between 2030 and 2035, a mission would need a delta-v budget of 11.801 km/s. is on NASA's automated Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) list of mission-accessible target asteroids.
See also 203 Pompeja – Another very red main belt asteroid
References
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External links