3425 Hurukawa

3425 Hurukawa, provisional designation 1929 BD, is a stony Eoan asteroid from the outer region of the asteroid belt, approximately 25 kilometers in diameter. It was discovered by German astronomer Karl Reinmuth at Heidelberg Observatory on 29 January 1929, and named after Japanese astronomer Kiichirō Furukawa.^[2][10]

3425 Hurukawa

Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	29 January 1929
Designations
MPC designation	(3425) Hurukawa
Named after	Kiichirō Furukawa (Japanese astronomer)[2]
Alternative designations	1929 BD · 1951 GB 1971 DJ1 · 1978 PN 1979 SG1 · 1981 DW3 A903 CB
Minor planet category	main-belt · Eos[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	114.16 yr (41,697 days)
Aphelion	3.2541 AU
Perihelion	2.7470 AU
Semi-major axis	3.0006 AU
Eccentricity	0.0845
Orbital period (sidereal)	5.20 yr (1,898 days)
Mean anomaly	66.235°
Mean motion	0° 11m 22.56s / day
Inclination	9.2123°
Longitude of ascending node	291.51°
Argument of perihelion	135.02°
Physical characteristics
Dimensions	21.21±0.38 km[4] 25.25 km (derived)[3] 25.36±2.8 km[5] 25.4 km[1] 27.81±0.54 km[6]
Synodic rotation period	16 h[7] 24.8158±0.0402 h[8] 24.84±0.01 h[7]
Geometric albedo	0.100±0.004[6] 0.1103 (derived)[3] 0.1315[5] 0.171±0.026[4]
Spectral type	S[3]
Absolute magnitude (H)	10.75±0.27[9] · 10.8[5] · 10.837±0.002 (R)[8] · 10.9[4][6] · 11.0[1][3]

Orbit and classification

Hurukawa is a member of the Eos family (606), the largest asteroid family in the outer main belt consisting of nearly 10,000 asteroids.. It orbits the Sun at a distance of 2.7–3.3 AU once every 5 years and 2 months (1,898 days). Its orbit has an eccentricity of 0.08 and an inclination of 9° with respect to the ecliptic.^[1] In 1903, a first precovery was taken at the discovering observatory, extending the asteroid's observation arc by 26 years prior to its official discovery.^[10]

Physical characteristics

Hurukawa has been characterized as a common S-type asteroid.^[3]

Rotation period

In September 2005, a rotational lightcurve of Hurukawa was obtained from photometric observations by French astronomer Raymond Poncy. It gave a well-defined, slightly longer-than-average rotation period of 24.84±0.01 hours with a brightness variation of 0.47 in magnitude (U=3-).^[7] The period was confirmed by observations taken at the U.S. Palomar Transient Factory in August 2010, which rendered a period of 24.8158±0.0402 hours and an amplitude of 0.17 (U=2),^[8] superseding a third period of 16 hours from a fragmentary lightcurve obtained by French astronomer René Roy in 2007 (U=1).^[7]

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Hurukawa measures between 21.3 and 27.8 kilometers in diameter and its surface has an untypically low albedo between 0.10 and 0.17.^[4][5][6] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.11 and a diameter of 25.3 kilometers.^[3]

Naming

This minor planet was named in honor of Japanese Kiichirō Furukawa (1929–2016), who was an astronomer at Tokyo Astronomical Observatory and an observer and discoverer of minor planets himself.^[2] The official naming citation was published by the Minor Planet Center on 16 December 1986 (M.P.C. 11443).^[11]