| Discovery[1] | |
|---|---|
| Discovered by | O. Oikawa |
| Discovery site | Tokyo Obs. (389) |
| Discovery date | 23 January 1927 |
| Designations | |
| (1266) Tone | |
| Pronunciation | /ˈtoʊni/ Japanese:[tone] |
Named after | Tone River[2] (Japaneseriver) |
| 1927 BD · 1933 BM 1934 EC · A899 PH | |
| main-belt · (outer)[1][3] background[4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 84.76 yr (30,958 days) |
| Aphelion | 3.5313AU |
| Perihelion | 3.1886 AU |
| 3.3600 AU | |
| Eccentricity | 0.0510 |
| 6.16yr (2,250 days) | |
| 102.82° | |
| 0° 9m 36s / day | |
| Inclination | 17.182° |
| 320.63° | |
| 298.20° | |
| Physical characteristics | |
| Dimensions | 70.70±24.76 km[5] 73.34±3.8 km[6] 75.470±0.523 km[7] 83.261±2.040 km[8] 88.82±1.33 km[9] 94.10±24.67 km[10] |
| 7.40±0.05h[11][a] 11.82±0.05 h[12] 12.9±0.1 h[13] | |
| 0.039±0.001[9] 0.0439±0.0101[8] 0.05±0.03[10] 0.05±0.04[5] 0.053±0.005[7] 0.0566±0.006[6] | |
| Tholen = P[1][3] B–V = 0.732[1] U–B = 0.317[1] | |
| 9.40[10] · 9.41[1][3][5][6][8][9] | |
1266 Tone/ˈtoʊni/ is a dark backgroundasteroid from the outer regions of theasteroid belt, approximately 80 kilometers in diameter. Discovered by astronomerOkuro Oikawa at the Tokyo Observatory in 1927,[14] it was assigned the provisional designation1927 BD. The asteroid was later named after theTone River, one of Japan's largest rivers.[2]
It was discovered by Japanese astronomerOkuro Oikawa at the Tokyo Observatory (389) on 23 January 1927.[14] On the following night, it was independently discovered by Soviet astronomerGrigory Neujmin at theSimeiz Observatory on the Crimean peninsula.[2] TheMinor Planet Center only recognizes the first discoverer.[14] In August 1899, the asteroid was first identified asA899 PH at theBoyden Station of theHarvard Observatory in Arequipa, Peru.[14]
Tone is a non-family asteroid from the main belt'sbackground population.[4] It orbits the Sun in theouter asteroid belt at a distance of 3.2–3.5 AU once every 6 years and 2 months (2,250 days;semi-major axis of 3.36 AU). Its orbit has aneccentricity of 0.05 and aninclination of 17° with respect to theecliptic.[1]
The body'sobservation arc begins with its identification as1933 BM at the GermanHeidelberg Observatory in January 1933, or four years after its official discovery observation at Tokyo.[14]
In theTholen classification,Tone is a primitive and darkP-type asteroid.[1][3]
In October 1999, two rotationallightcurves ofTone were obtained from photometric observations by American astronomerBrian Warner at his Palmer Divide Observatory (716) in Colorado. Lightcurve analysis gave two divergentrotation periods of 7.40 and 11.82 hours with a brightness variation of 0.06 and 0.12magnitude, respectively (U=2/2).[11][12][a] Observation by Italian astronomers Roberto Crippa and Federico Manzini in October 2005, gave another tentative period of 12.9 hours and an amplitude of 0.07 magnitude (U=2-).[13] The LCDB currently adopts a period of 7.40 hours.[3]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Tone measures between 70.70 and 94.10 kilometers in diameter and its surface has analbedo between 0.039 and 0.0566.[5][6][7][8][9][10]
TheCollaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0566 and a diameter of 73.34 kilometers based on anabsolute magnitude of 9.41.[3]
Thisminor planet was named afterTone River (Tone-gawa), Japan's second-largest river after theShinano River.[2] The official naming citation was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 116).
