1971 Hagihara

1971 Hagihara, provisional designation 1955 RD1, is an Eoan asteroid from the outer region of the asteroid belt, approximately 12 kilometers in diameter.

1971 Hagihara
Discovery [1]
Discovered byIndiana University
(Indiana Asteroid Program)
Discovery siteGoethe Link Obs.
Discovery date14 September 1955
(1971) Hagihara
Named after
Yusuke Hagihara
1955 RD1 · 1971 TZ2
main-belt · (outer)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc59.65 yr (21,787 days)
Aphelion3.2479 AU
Perihelion2.7370 AU
2.9924 AU
5.18 yr (1,891 days)
0° 11m 25.44s / day
Physical characteristics
15±7 km (converted)[5]

It was discovered on 14 September 1955, by the Indiana Asteroid Program at the Goethe Link Observatory near Brooklyn, Indiana, United States.[6] It was later named after Japanese astronomer Yusuke Hagihara.[2]

Orbit and classificationEdit

Hagihara is a member of the Eos family (606), the largest asteroid family in the outer main belt consisting of nearly 10,000 asteroids.[3][7]:23 It orbits the Sun in the outer main-belt at a distance of 2.7–3.2 AU once every 5 years and 2 months (1,891 days). Its orbit has an eccentricity of 0.09 and an inclination of 9° with respect to the ecliptic.[1] The asteroid's observation arc begins with its discovery observation at Goethe in September 1955.[6]

Physical characteristicsEdit

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Hagihara measures 12.3 kilometers in diameter and its surface has an albedo of 0.135, which is neither typical for stony nor for carbonaceous bodies.[1][4] As of 2017, the asteroid's composition and spectral type, as well as its rotation period and shape remain unknown.[8]


This minor planet was named in honour of Yusuke Hagihara (1897–1979) on the occasion of his 81st birthday. He was professor of astronomy at the University of Tokyo and director of the Tokyo Observatory. He also served as vice-president of the International Astronomical Union and was the president of its Commission VII.

Hagihara is best known for the discussion of stability problems in celestial mechanics and his theory of libratory motions, as well as for important contributions to the study of the velocity distribution of free electrons in planetary nebulae, and his important five-volume treatise on celestial mechanics.[2] The official naming citation was published by the Minor Planet Center on 1 August 1978 (M.P.C. 4419).[9]


  1. ^ a b c d e f g "JPL Small-Body Database Browser: 1971 Hagihara (1955 RD1)" (2015-05-09 last obs.). Jet Propulsion Laboratory. Retrieved 1 July 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1971) Hagihara". Dictionary of Minor Planet Names – (1971) Hagihara. Springer Berlin Heidelberg. p. 159. doi:10.1007/978-3-540-29925-7_1972. ISBN 978-3-540-00238-3.
  3. ^ a b "Asteroid 1971 Hagihara – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 26 October 2019.
  4. ^ 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. Retrieved 29 August 2016.
  5. ^ "Asteroid Size Estimator". CNEOS NASA/JPL. Retrieved 12 November 2017.
  6. ^ a b c "1971 Hagihara (1955 RD1)". Minor Planet Center. Retrieved 29 August 2016.
  7. ^ 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.
  8. ^ "LCDB Data for (1971) Hagihara". Asteroid Lightcurve Database (LCDB). Retrieved 4 April 2017.
  9. ^ Schmadel, Lutz D. "Appendix – Publication Dates of the MPCs". Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008). Springer Berlin Heidelberg. p. 221. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7.

External linksEdit