(219774) 2001 YY145

(219774) 2001 YY145
Discovery [1]
Discovered byLONEOS
Discovery siteAnderson Mesa Stn.
Discovery date18 December 2001
(219774) 2001 YY145
2001 YY145 · 2005 TA170
main-belt[1][2] · (middle)
Orbital characteristics[2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc15.92 yr (5,815 d)
Aphelion2.9215 AU
Perihelion2.2404 AU
2.5810 AU
4.15 yr (1,515 d)
0° 14m 15.72s / day
Physical characteristics
Mean diameter
1.54 km (calculated)[5]
1007.6706±86.3718 h[4][6]
0.20 (assumed)[5]
S (assumed)[5]
15.977±0.011 (R)[6]

(219774) 2001 YY145, provisional designation 2001 YY145 is a stony background asteroid and exceptionally slow rotator from the central region of the asteroid belt, approximately 1.5 kilometers (0.9 miles) in diameter. It was discovered on 18 December 2001, by astronomers with the Lowell Observatory Near-Earth-Object Search at Anderson Mesa Station near Flagstaff, Arizona, in the United States.[1] The assumed S-type asteroid is likely elongated and has a rarely seen rotation period of 1007 hours, making it the 13th slowest rotator.[5]

Orbit and classification[]

2001 YY145 is a non-family asteroid from the main belt's background population.[3][4] It orbits the Sun in the central main-belt at a distance of 2.2–2.9 AU once every 4 years and 2 months (1,515 days; semi-major axis of 2.58 AU). Its orbit has an eccentricity of 0.13 and an inclination of 10° with respect to the ecliptic.[2] A first precovery was taken at Lincoln Lab's ETS in October 2001, extending the asteroid's observation arc by 2 months prior to its official discovery observation at Anderson Mesa.[1]

Physical characteristics[]

The object is an assumed, common S-type asteroid.[5]

Slow rotator[]

In October 2013, a rotational lightcurve was obtained of this asteroid from photometric observations in the R-band by astronomers at the Palomar Transient Factory in California. It gave a rotation period of 1007.7 hours – or nearly 42 days – with an assigned error margin of ±86 hours. According to the Light Curve Data Base, it is the 13th slowest rotating minor planet known to exist among more than 15,000 observed small Solar System bodies. Due to its high brightness variation of 0.86 magnitude, the body is likely to have a non-spheroidal shape (U=2).[6] As of 2018, no follow-up observation have been published.[5]

Diameter and albedo[]

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.[5]

Numbering and naming[]

This minor planet was numbered by the Minor Planet Center on 4 October 2009.[7] As of 2018, it has not been named.[1]


  1. ^ a b c d e f "219774 (2001 YY145)". Minor Planet Center. Retrieved 6 June 2018.
  2. ^ a b c d "JPL Small-Body Database Browser: 219774 (2001 YY145)" (2017-09-26 last obs.). Jet Propulsion Laboratory. Retrieved 6 June 2018.
  3. ^ a b "Asteroid (219774) – Proper elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 25 May 2018.
  4. ^ a b c "Asteroid (219774) 2001 YY145". Small Bodies Data Ferret. Retrieved 6 June 2018.
  5. ^ a b c d e f g h "LCDB Data for (219774)". Asteroid Lightcurve Database (LCDB). Retrieved 13 September 2016.
  6. ^ a b c Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75.
  7. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 24 February 2018.

External links[]