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 by	Indiana University (Indiana Asteroid Program)
Discovery site	Goethe Link Obs.
Discovery date	14 September 1955
Designations
MPC designation	(1971) Hagihara
Named after	Yusuke Hagihara (astronomer)[2]
Alternative designations	1955 RD1 · 1971 TZ2
Minor planet category	main-belt · (outer) Eos[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	59.65 yr (21,787 days)
Aphelion	3.2479 AU
Perihelion	2.7370 AU
Semi-major axis	2.9924 AU
Eccentricity	0.0854
Orbital period (sidereal)	5.18 yr (1,891 days)
Mean anomaly	294.31°
Mean motion	0° 11m 25.44s / day
Inclination	8.6990°
Longitude of ascending node	300.12°
Argument of perihelion	120.50°
Physical characteristics
Dimensions	12.289±0.156[1][4] 15±7 km (converted)[5]
Geometric albedo	0.135±0.028[1][4]
Absolute magnitude (H)	12.3[6][1]

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 classification

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 characteristics

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]

Naming

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]

References

1. "JPL Small-Body Database Browser: 1971 Hagihara (1955 RD1)" (2015-05-09 last obs.). Jet Propulsion Laboratory. Retrieved 1 July 2017.
2. Schmadel, Lutz D. (2007). "(1971) Hagihara". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 159. doi:10.1007/978-3-540-29925-7_1972. ISBN 978-3-540-00238-3.
3. "Asteroid 1971 Hagihara – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 26 October 2019.
4. 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. "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 978-0-8165-3213-1.
8. "LCDB Data for (1971) Hagihara". Asteroid Lightcurve Database (LCDB). Retrieved 4 April 2017.
9. Schmadel, Lutz D. (2009). "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 links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 1971 Hagihara at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1971 Hagihara at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters