1266 Tone /ˈtoʊni/ is a dark background asteroid from the outer regions of the asteroid belt, approximately 80 kilometers in diameter. Discovered by astronomer Okuro Oikawa at the Tokyo Observatory in 1927, ^[14] it was assigned the provisional designation 1927 BD. The asteroid was later named after the Tone River, one of Japan's largest rivers. ^[2]

Discovery

It was discovered by Japanese astronomer Okuro Oikawa at the Tokyo Observatory ( 389) on 23 January 1927. ^[14] On the following night, it was independently discovered by Soviet astronomer Grigory Neujmin at the Simeiz Observatory on the Crimean peninsula. ^[2] The Minor Planet Center only recognizes the first discoverer. ^[14] In August 1899, the asteroid was first identified as A899 PH at the Boyden Station of the Harvard Observatory in Arequipa, Peru. ^[14]

Orbit and classification

Tone is a non- family asteroid from the main belt's background population. ^[4] It orbits the Sun in the outer 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 an eccentricity of 0.05 and an inclination of 17 ° with respect to the ecliptic. ^[1]

The body's observation arc begins with its identification as 1933 BM at the German Heidelberg Observatory in January 1933, or four years after its official discovery observation at Tokyo. ^[14]

Physical characteristics

In the Tholen classification, Tone is a primitive and dark P-type asteroid. ^{[1] [3]}

Rotation period

In October 1999, two rotational lightcurves of Tone were obtained from photometric observations by American astronomer Brian Warner at his Palmer Divide Observatory ( 716) in Colorado. Lightcurve analysis gave two divergent rotation periods of 7.40 and 11.82 hours with a brightness variation of 0.06 and 0.12 magnitude, 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]

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Tone measures between 70.70 and 94.10 kilometers in diameter and its surface has an albedo between 0.039 and 0.0566. ^{[5] [6] [7] [8] [9] [10]}

The Collaborative 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 an absolute magnitude of 9.41. ^[3]

Naming

This minor planet was named after Tone River (Tone-gawa), Japan's second-largest river after the Shinano River. ^[2] The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 ( H 116).

Notes

References

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
• 1266 Tone at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1266 Tone at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters