| Discovered by LONEOS MPC designation (219774) 2001 YY145 Observation arc 14.50 yr (5,297 days) Discovery site Anderson Mesa Station | Discovery date 18 December 2001 Minor planet category main-belt · (middle) Discovered 18 December 2001 | |
| Alternative names 2001 YY145 · 2005 TA170 Discoverer Lowell Observatory Near-Earth-Object Search | ||
(219774) 2001 YY145 is a stony asteroid and exceptionally slow rotator from the middle region of the asteroid belt, approximately 1.5 kilometers in diameter. It was discovered on 18 December 2001, by the U.S. Lowell Observatory Near-Earth-Object Search (LONEOS) at Anderson Mesa Station near Flagstaff, Arizona.
The S-type asteroid orbits the Sun at a distance of 2.2–2.9 AU once every 4 years and 2 months (1,514 days). Its orbit has an eccentricity of 0.13 and an inclination of 10° with respect to the ecliptic. The first precovery was taken at Lincoln Lab's ETS in October 2001, extending the asteroid's observation arc by 2 months prior to its discovery observation.
A rotational light-curve was obtained for this asteroid from photometric observations at the Californian Palomar Transient Factory in October 2013. It gave a rotation period of 1007.7 hours with an estimated error margin of ±86 hours. According to the Light Curve Data Base, it is the 11th slowest rotating minor planet known to exist. Due to its high brightness variation of 0.86 magnitude, the body is likely to have a non-spheroidal shape (U=2).
The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 1.54 kilometers, based on an absolute magnitude of 16.43.