_Hakone.png) Modelled shape ofHakone from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | O. Oikawa |
| Discovery site | Tokyo Astronomical Obs. |
| Discovery date | 5 September 1928 |
| Designations | |
| (1098) Hakone | |
| Pronunciation | Japanese:[hakone] |
Named after | Mount Hakone (Japanese volcanic mountain)[2] |
| 1928 RJ · 1926 EC 1950 QH1 · 1952 BE1 A906 RD · A917 DD | |
| Orbital characteristics[3] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 110.19 yr (40,247 days) |
| Aphelion | 3.0081AU |
| Perihelion | 2.3686 AU |
| 2.6884 AU | |
| Eccentricity | 0.1189 |
| 4.41yr (1,610 days) | |
| 13.741° | |
| 0° 13m 24.96s / day | |
| Inclination | 13.377° |
| 329.00° | |
| 80.805° | |
| Physical characteristics | |
| 24.44 km(derived)[6] 24.73±1.1 km[7] 24.90±0.57 km[8] 26.684±0.397 km[9] 29.567±0.135 km[10] | |
| 7.14±0.01 h[11] 7.14117±0.00001 h[12] 7.142±0.002 h[13] 7.16±0.050 h[14] | |
| (40.0°, 43.0°) (λ1/β1)[5] | |
| 0.1745±0.0334[10] 0.1865(derived)[6] 0.206±0.009[9] 0.2404±0.022[7] 0.245±0.013[8] | |
| SMASS =Xe[3] · M[10] · X[6] | |
| 10.20[7][8][10] · 10.350±0.120(R)[14] · 10.5[3][6] | |
1098 Hakone (prov. designation:1928 RJ) is abackground asteroid from the central regions of theasteroid belt. TheX-type asteroid has arotation period of 7.1 hours and measures approximately 25 kilometers (16 miles) in diameter. Discovered by Japanese astronomerOkuro Oikawa at Tokyo Observatory in 1928, the asteroid was later named after the volcanicMount Hakone in Japan.
Located in the orbital region of the stonyEunomia family,[6]Hakone is a non-family asteroid from the main belt'sbackground population when applying thehierarchical clustering method to its proper orbital elements.[4][5] It orbits the Sun in thecentral asteroid belt at a distance of 2.4–3.0 AU once every 4 years and 5 months (1,610 days). Its orbit has aneccentricity of 0.12 and aninclination of 13° with respect to theecliptic.[3]
Hakone was discovered by Japanese astronomerOkuro Oikawa at the old Tokyo Astronomical Observatory (389) on 5 September 1928.[1] It was independently discovered by German astronomerMax Wolf atHeidelberg Observatory and Soviet astronomerGrigory Neujmin at theSimeiz Observatory on the Crimean peninsula on 9 and 11 September 1928, respectively.[2] TheMinor Planet Center, however, only acknowledges the first discoverer.[1] The asteroid was first observed asA906 RD at Taunton Observatory (803) on 16 September 1906. The body'sobservation arc begins the following month at theU.S. Naval Observatory, almost 22 years prior to its official discovery observation at Tokyo.[1]
Thisminor planet was named after the volcanicMount Hakone, located 80 kilometers from the discovering Tokyo Astronomical Observatory and near the Japanese town ofHakone. The mountain resort is known for its hot springs,Lake Ashi and its view ofMount Fuji, after which the asteroid1584 Fuji was named. The official naming citation was prepared by astronomerKōichirō Tomita.[2]
In theSMASS classification,Hakone is a Xe-subtype, that transitions from theX-type the very brightE-type asteroids.[3] It has also been characterized as a metallicM-type asteroid, by theWide-field Infrared Survey Explorer.[10]
Several rotationallightcurves ofHakone were obtained fromphotometric observations. Analysis of the best-rated lightcurve by French amateur astronomerLaurent Bernasconi gave arotation period of 7.142 hours with a brightness amplitude of 0.35magnitude (U=3/3/2).[11][13][14]
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°) inecliptic coordinates (λ, β).[12]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA's WISE telescope,Hakone measures between 24.73 and 29.567 kilometers in diameter and its surface has analbedo between 0.1745 and 0.245.[7][8][9][10]
TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.1865 and a diameter of 24.44 kilometers based on anabsolute magnitude of 10.5.[6]
