1098 Hakone

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1098 Hakone
Discovery [1]
Discovered byO. Oikawa
Discovery siteTokyo Astronomical Obs.
Discovery date5 September 1928
MPC designation(1098) Hakone
Named after
Mount Hakone
(Japanese volcanic mountain)[2]
1928 RJ · 1926 EC
1950 QH1 · 1952 BE1
A906 RD · A917 DD
main-belt · (middle)
Eunomia[3] · background[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc110.19 yr (40,247 days)
Aphelion3.0081 AU
Perihelion2.3686 AU
2.6884 AU
4.41 yr (1,610 days)
0° 13m 24.96s / day
Physical characteristics
Dimensions24.44 km (derived)[3]
24.73±1.1 km[5]
24.90±0.57 km[6]
26.684±0.397 km[7]
29.567±0.135 km[8]
7.14±0.01 h[9]
7.14117±0.00001 h[10]
7.142±0.002 h[11]
7.16±0.050 h[12]
0.1865 (derived)[3]
SMASS = Xe [1] · M[8] · X[3]
10.20[5][6][8] · 10.350±0.120 (R)[12] · 10.5[1][3]

1098 Hakone, provisional designation 1928 RJ, is a Eunomian asteroid from the central regions of the asteroid belt, approximately 25 kilometers in diameter. Discovered by Japanese astronomer Okuro Oikawa at Tokyo Observatory in 1928, the asteroid was later named after the volcanic Mount Hakone in Japan.


Hakone was discovered by Japanese astronomer Okuro Oikawa at the old Tokyo Astronomical Observatory (389) on 5 September 1928.[13] It was independently discovered by German astronomer Max Wolf at Heidelberg Observatory and Soviet astronomer Grigory Neujmin at the Simeiz Observatory on the Crimean peninsula on 9 and 11 September 1928, respectively.[2] The Minor Planet Center, however, only acknowledges the first discoverer.[13]

The asteroid was first identified as A906 RD at Taunton Observatory (806) in September 1906. The body's observation arc begins the following month at the U.S. Naval Observatory, almost 22 years prior to its official discovery observation at Tokyo.[13]

Orbit and classification[edit]

Based on its orbital parameters, Hakone is a member of the Eunomia family (502),[3] a prominent family of stony S-type asteroid and the largest one in the intermediate main belt with more than 5,000 members. However, Hakone turns out to be a non-family asteroid from the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[4]

It orbits the Sun in the central main-belt at a distance of 2.4–3.0 AU once every 4 years and 5 months (1,610 days). Its orbit has an eccentricity of 0.12 and an inclination of 13° with respect to the ecliptic.[1]

Physical characteristics[edit]

In the SMASS classification, Hakone is a Xe-subtype, that transitions from the X-type the very bright E-type asteroids.[1] It has also been characterized as a metallic M-type asteroid, by the Wide-field Infrared Survey Explorer.[8]

Rotation period[edit]

Several rotational lightcurves of Hakone were obtained from photometric observations. Analysis of the best-rated lightcurve by French amateur astronomer Laurent Bernasconi gave a rotation period of 7.142 hours with a brightness amplitude of 0.35 magnitude (U=3/3/2).[9][11][12]

Spin axis[edit]

A 2016-published lightcurve, using modeled photometric data from the Lowell Photometric Database (LPD), gave a concurring period of 7.14117 hours, as well as a spin axis of (40.0°, 43.0°) in ecliptic coordinates (λ, β).[10]

Diameter and albedo[edit]

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's WISE telescope, Hakone measures between 24.73 and 29.567 kilometers in diameter and its surface has an albedo between 0.1745 and 0.245.[5][6][7][8]

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1865 and a diameter of 24.44 kilometers based on an absolute magnitude of 10.5.[3]


This minor planet was named after the volcanic Mount Hakone, located 80 kilometers from the discovering Tokyo Astronomical Observatory and near the Japanese town of Hakone. The mountain resort is known for its hot springs, Lake Ashi and its view of Mount Fuji, after which the asteroid 1584 Fuji was named. The official naming citation was prepared by astronomer Kōichirō Tomita.[2]


  1. ^ a b c d e f "JPL Small-Body Database Browser: 1098 Hakone (1928 RJ)" (2016-12-21 last obs.). Jet Propulsion Laboratory. Retrieved 25 September 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1098) Hakone". Dictionary of Minor Planet Names – (1098) Hakone. Springer Berlin Heidelberg. p. 93. doi:10.1007/978-3-540-29925-7_1099. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f g "LCDB Data for (1098) Hakone". Asteroid Lightcurve Database (LCDB). Retrieved 25 September 2017.
  4. ^ a b "Asteroid 1098 Hakone – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 28 October 2019.
  5. ^ a b c d Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 22 October 2019.
  6. ^ 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)
  7. ^ 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 25 September 2017.
  8. ^ a b c d e f 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.
  9. ^ a b Lecrone, Crystal; Addleman, Don; Butler, Thomas; Hudson, Erin; Mulvihill, Alex; Reichert, Chris; et al. (September 2005). "2004–2005 winter observing campaign at Rose-Hulman Institute: results for 1098 Hakone, 1182 Ilona, 1294 Antwerpia, 1450 Raimonda, 2251 Tikhov, and 2365 Interkosmos". The Minor Planet Bulletin. 32 (3): 46–48. Bibcode:2005MPBu...32...46L. ISSN 1052-8091. Retrieved 25 September 2017.
  10. ^ a b Durech, J.; Hanus, J.; Oszkiewicz, D.; Vanco, R. (March 2016). "Asteroid models from the Lowell photometric database". Astronomy and Astrophysics. 587: 6. arXiv:1601.02909. Bibcode:2016A&A...587A..48D. doi:10.1051/0004-6361/201527573. Retrieved 25 September 2017.
  11. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1098) Hakone". Geneva Observatory. Retrieved 25 September 2017.
  12. ^ a b c Chang, Chan-Kao; Ip, Wing-Huen; Lin, Hsing-Wen; Cheng, Yu-Chi; Ngeow, Chow-Choong; Yang, Ting-Chang; et al. (August 2015). "Asteroid Spin-rate Study Using the Intermediate Palomar Transient Factory". The Astrophysical Journal Supplement Series. 219 (2): 19. arXiv:1506.08493. Bibcode:2015ApJS..219...27C. doi:10.1088/0067-0049/219/2/27. Retrieved 25 September 2017.
  13. ^ a b c "1098 Hakone (1928 RJ)". Minor Planet Center. Retrieved 25 September 2017.

External links[edit]