6025 Naotosato, provisional designation 1992 YA3, is an Eoan asteroid from the outer region of the asteroid belt, approximately 19 kilometers in diameter. It was discovered on 30 December 1992, by Japanese astronomer Takeshi Urata at the Nihondaira Observatory in Oohira, Japan.[9] The asteroid was named after Japanese amateur astronomer Naoto Satō.[2]

6025 Naotosato
Discovery [1]
Discovered byT. Urata
Discovery siteNihondaira Obs.
Discovery date30 December 1992
MPC designation(6025) Naotosato
Named after
Naoto Satō
(Japanese astronomer)[2]
1992 YA3 · 1954 SG1
1965 UO · 1977 BK
1983 EE1 · 1986 TL11
1987 YS2 · 1990 HF2
1991 RS29
main-belt · Eos[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc62.68 yr (22,895 days)
Aphelion3.2334 AU
Perihelion2.8116 AU
3.0225 AU
5.25 yr (1,919 days)
0° 11m 15.36s / day
Physical characteristics
Dimensions17.80 km (calculated)[3]
19.90±0.91 km[5]
19.968±0.172 km[6]
10 h[7]
0.14 (assumed)[3]
11.2[5][6] · 11.5[1][3] · 11.70±0.28[8]

Orbit and classificationEdit

Naotosato is a member of the Eos family (606), the largest asteroid family in the outer main belt, consisting of nearly 10,000 asteroids.

It orbits the Sun at a distance of 2.8–3.2 AU once every 5 years and 3 months (1,919 days). Its orbit has an eccentricity of 0.07 and an inclination of 9° with respect to the ecliptic.[1] The first observation was made at Goethe Link Observatory in 1954, extending the asteroid's observation arc by 38 years prior to its discovery.[9]

Physical characteristicsEdit

Rotation periodEdit

In September 2009, a rotational lightcurve of Naotosato was obtained from photometric observations by French astronomer René Roy. The fragmentary lightcurve gave a longer-than average rotation period of 10 hours with a brightness amplitude of 0.20 in magnitude (U=1).[7]

Diameter and albedoEdit

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Naotosato measures between 18.4 and 20.0 kilometers in diameter and its surface has an albedo between 0.148 and 0.188,[4][5][6] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.14 and calculates a diameter of 17.8 kilometers with an absolute magnitude of 11.5.[3]


This minor planet was named after Japanese amateur astronomer Naoto Satō (born 1953), by profession a junior high school science teacher and a prolific discoverer of minor planets from his private Chichibu Observatory himself. He has also prediscovered C/1989 Y2, a parabolic comet credited to McKenzie–Russell.[2] The official naming citation was published by the Minor Planet Center on 2 February 1999 (M.P.C. 33786).[10]


  1. ^ a b c d "JPL Small-Body Database Browser: 6025 Naotosato (1992 YA3)" (2017-06-03 last obs.). Jet Propulsion Laboratory. Retrieved 21 June 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(6025) Naotosato". Dictionary of Minor Planet Names – (6025) Naotosato. Springer Berlin Heidelberg. p. 504. doi:10.1007/978-3-540-29925-7_5598. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f "LCDB Data for (6025) Naotosato". Asteroid Lightcurve Database (LCDB). Retrieved 27 July 2016.
  4. ^ a b c Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 5 December 2016.
  5. ^ a b c d Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. Retrieved 17 October 2019. (online, AcuA catalog p. 153)
  6. ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
  7. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (6025) Naotosato". Geneva Observatory. Retrieved 27 July 2016.
  8. ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 27 July 2016.
  9. ^ a b "6025 Naotosato (1992 YA3)". Minor Planet Center. Retrieved 27 July 2016.
  10. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 27 July 2016.

External linksEdit