5855 Yukitsuna, provisional designation 1992 UO2, is a stony Marian asteroid from the central regions of the asteroid belt, approximately 11 kilometers (7 miles) in diameter. It was discovered on 26 October 1992, by Japanese astronomers Akira Natori and Takeshi Urata at the JCPM Yakiimo Station.[1] The likely elongated S-type asteroid has a rotation period of 19 hours.[4] It was named for Minamoto no Yukitsuna, a Japanese general during the Heian era.[1]

5855 Yukitsuna
Discovery [1]
Discovered byA. Natori
T. Urata
Discovery siteJCPM Yakiimo Stn.
Discovery date26 October 1992
MPC designation(5855) Yukitsuna
Named after
Minamoto no Yukitsuna[1]
(Japanese general)
1992 UO2 · 1943 UF
1974 FQ1 · 1988 VD9
1988 XO3
main-belt[1][2] · (middle)
Maria[3] · Eunomia[4]
Orbital characteristics[2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc74.49 yr (27,207 d)
Aphelion2.9480 AU
Perihelion2.1566 AU
2.5523 AU
4.08 yr (1,489 d)
0° 14m 30.12s / day
Physical characteristics
Mean diameter
10.585±0.245 km[5]
11.03 km (calculated)[4]
11.100±0.138 km[6]
19.04±0.04 h[7]
19.2 h[8]
0.21 (assumed)[4]
S (assumed)[4]


Orbit and classificationEdit

Yukitsuna is a core member of the Maria family (506),[3] a large intermediate belt family of stony asteroids.[9] Alternatively, it has also been assigned to the stony Eunomia family (502), one of the most prominent families in the intermediate main belt with more than 5,000 members.[4]

It orbits the Sun in the central main-belt at a distance of 2.2–2.9 AU once every 4 years and 1 month (1,489 days; semi-major axis of 2.55 AU). Its orbit has an eccentricity of 0.16 and an inclination of 16° with respect to the ecliptic.[2]

The asteroid was first observed as 1943 UF at Heidelberg Observatory in October 1943. The body's observation arc begins as 1974 FQ1 at Crimea–Nauchnij in March 1974, more than 17 years prior to its official discovery observation at Yakiimo.[1]

Physical characteristicsEdit

Yukitsuna is an assumed S-type asteroid,[4] as is the overall spectral type of both the Maria and Eunomia family.[9]:23

Rotation periodEdit

In January 2006, a rotational lightcurve of Yukitsuna was obtained from photometric observations by Federico Manzini at the Sozzago Astronomical Station (A12) in Italy. Lightcurve analysis gave a rotation period of 19.2 hours with a brightness variation of 0.8 magnitude (U=2).[8] In September 2008, a more refined period of 19.04 hours and an amplitude of 0.80 magnitude was measured at the Oakley Southern Sky Observatory and Oakley Observatory (U=2+).[7] The high brightness variation of 0.8 magnitude is indicative for an elongated, non-spherical shape.

Diameter and albedoEdit

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Yukitsuna measures between 10.585 and 11.100 kilometers in diameter and its surface has an albedo between 0.273 and 0.3002.[5][6]

The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.21 – derived from 15 Eunomia, the parent body of the Eunomia family – and calculates a diameter of 11.03 kilometers based on an absolute magnitude of 12.1.[4]


This minor planet was named after Minamoto no Yukitsuna, a general of the late Heian period of Japanese history.[1] The official naming citation was published by the Minor Planet Center on 14 December 1997 (M.P.C. 31024).[10]


  1. ^ a b c d e f g "5855 Yukitsuna (1992 UO2)". Minor Planet Center. Retrieved 27 May 2018.
  2. ^ a b c d "JPL Small-Body Database Browser: 5855 Yukitsuna (1992 UO2)" (2018-04-26 last obs.). Jet Propulsion Laboratory. Retrieved 27 May 2018.
  3. ^ a b "Asteroid 5855 Yukitsuna". Small Bodies Data Ferret. Retrieved 27 May 2018.
  4. ^ a b c d e f g h i "LCDB Data for (5855) Yukitsuna". Asteroid Lightcurve Database (LCDB). Retrieved 27 May 2018.
  5. ^ 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. (catalog)
  6. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68.
  7. ^ a b Carbo, Landy; Kragh, Katherine; Krotz, Jonathan; Meiers, Andrew; Shaffer, Nelson; Torno, Steven; et al. (July 2009). "Asteroid Lightcurve Analysis at the Oakley Southern Sky Observatory and Oakley Observatory: 2008 September and October". The Minor Planet Bulletin. 36 (3): 91–94. Bibcode:2009MPBu...36...91C. ISSN 1052-8091.
  8. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (5855) Yukitsuna". Geneva Observatory. Retrieved 27 May 2018.
  9. ^ a b Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). Identification and Dynamical Properties of Asteroid Families. Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131.
  10. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 27 May 2018.

External linksEdit