6980 Kyusakamoto

6980 Kyusakamoto, provisional designation 1993 SV₁, is a stony Koronis asteroid from the outer region of the asteroid belt, approximately 9 kilometers in diameter. It was discovered by Japanese astronomers Kin Endate and Kazuro Watanabe at Kitami Observatory on 16 September 1993.^[8] The asteroid was named after Japanese singer Kyu Sakamoto.^[2]

6980 Kyusakamoto

Discovery[1]
Discovered by	K. Endate K. Watanabe
Discovery site	Kitami Obs.
Discovery date	16 September 1993
Designations
MPC designation	(6980) Kyusakamoto
Named after	Kyu Sakamoto (Japanese singer)[2]
Alternative designations	1993 SV1 · 1979 WH7 1988 RU13
Minor planet category	main-belt · Koronis[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	36.98 yr (13,508 days)
Aphelion	2.9663 AU
Perihelion	2.7030 AU
Semi-major axis	2.8347 AU
Eccentricity	0.0464
Orbital period (sidereal)	4.77 yr (1,743 days)
Mean anomaly	62.052°
Mean motion	0° 12m 23.4s / day
Inclination	3.2909°
Longitude of ascending node	97.461°
Argument of perihelion	211.58°
TJupiter	3.3080
Physical characteristics
Dimensions	8.791±0.081 km[4][5] 8.98 km (calculated)[3]
Synodic rotation period	3.2526±0.0042 h (R)[6] 3.2529±0.0042 h (S)[6]
Geometric albedo	0.24 (assumed)[3] 0.301±0.037[4][5]
Spectral type	S[3]
Absolute magnitude (H)	12.2[4] · 12.367±0.002 (R)[6] · 12.4[1][3] · 12.45±0.07[7] · 12.966±0.003 (S)[6]

Orbit and classification

Kyusakamoto is a member of the Koronis family, which is named after 158 Koronis and consists of about 300 known bodies with nearly ecliptical orbits. It orbits the Sun in the outer main-belt at a distance of 2.7–3.0 AU once every 4 years and 9 months (1,743 days). Its orbit has an eccentricity of 0.05 and an inclination of 3° with respect to the ecliptic.^[1]

In November 1979, it was first identified as 1979 WH₇ at Crimea–Nauchnij, extending the body's observation arc by 14 years prior to its official discovery observation at Kitami.^[8]

Physical characteristics

Rotation period

In August 2012, a rotational lightcurve of Kyusakamoto was obtained through photometric observations at the Palomar Transient Factory, California. The lightcurve showed a period of 3.2529±0.0042 hours with a brightness amplitude of 0.40 in magnitude (U=2). In the Mould-R filter (R), a different photometric band, the observations rendered a nearly identical period of 3.2526±0.0042 hours with an amplitude of 0.41 (U=2).^[6]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, Kyusakamoto measures 8.8 kilometers in diameter and its surface has a high albedo of 0.30,^[4][5] while the Collaborative Asteroid Lightcurve Link assumes a stony albedo of 0.24 and calculates a slightly larger diameter of 9.0 kilometers.^[3]

Naming

This minor planet was named in memory of Japanese popular singer Kyu Sakamoto (1941–1985), who died in the crash of Japan Air Lines Flight 123, the deadliest single-aircraft accident in history. Adored as "Kyu-chan", he is best known for his hit, I Look Up As I Walk ("Sukiyaki"), which became a worldwide bestseller. The naming also refers to his collaborators Rokusuke Ei and Hachidai Nakamura, songwriter and pianist, respectively.^[2] The official naming citation was published by the Minor Planet Center on 5 October 1998 (M.P.C. 32789).^[9]