6489 Golevka

6489 Golevka is an Apollo, Mars-crosser, and Alinda asteroid discovered in 1991 by Eleanor F. Helin.

6489 Golevka

Computer-generated model of Golevka based on Arecibo radar data
Discovery
Discovered by	Eleanor F. Helin
Discovery date	10 May 1991
Designations
MPC designation	(6489) Golevka
Alternative designations	1991 JX
Minor planet category	Alinda Apollo PHA [1] Mars-crosser
Orbital characteristics[1]
Epoch 6 November 2001 (JD 2452219.5)
Uncertainty parameter 0
Observation arc	8968 days (24.55 yr)
Aphelion	4.021663 AU (601.6322 Gm)
Perihelion	0.992813 AU (148.5227 Gm)
Semi-major axis	2.507238 AU (375.0775 Gm)
Eccentricity	0.604021
Orbital period	3.97 yr (1450.1 d)
Mean anomaly	213.841234°
Mean motion	0° 14m 53.744s / day
Inclination	2.278065°
Longitude of ascending node	211.596909°
Argument of perihelion	65.939347°
Earth MOID	0.0288423 AU (4.31475 Gm)
Jupiter MOID	1.13922 AU (170.425 Gm)
TJupiter	3.181
Physical characteristics
Dimensions	0.53 km[1]
Mean radius	0.265±0.015 km
Mass	2.10×1011 kg
Mean density	2.7+0.4 −0.6 g/cm3
Rotation period	6.026 h (0.2511 d)[1]
Geometric albedo	0.151 ± 0.023[1]
Spectral type	Q
Absolute magnitude (H)	19.2[1]

Its name has a complicated origin. In 1995, Golevka was studied simultaneously by three radar observatories across the world: Goldstone in California, Yevpatoria RT-70 radio telescope in Ukraine (Yevpatoria is sometimes romanized as Evpatoria) and Kashima in Japan. 'Golevka' comes from the first few letters of each observatory's name; it was proposed by the discoverer following a suggestion by Alexander L. Zaitsev.

Golevka is a small object, measuring 0.6 × 1.4 km. The radar observations revealed that it has a very strange, angular shape that looks different depending on the direction. In 2003 the Yarkovsky effect was first observed at work by high-precision radar observations of Golevka.[2] Between 1991 and 2003, the small force of the Yarkovsky effect caused a shift of 15 kilometers (9.3 mi) from what would be expected based on only gravitational interactions.[2] This helped evaluate the asteroid's bulk density (2.7 ± 0.5 g/cm³) and mass (2.10×10¹¹ kg).

Golevka approaches Earth to 0.05 AU (7,500,000 km; 4,600,000 mi) in 2046, 0.10 AU in 2069, and 0.11 AU in 2092.[3] On the other hand, Golevka's collision probability with any planet is negligible for at least the next nine centuries.[4] Its orbit is strikingly similar to that of 4179 Toutatis in eccentricity, semi-major axis, and inclination. However, Toutatis is better known due to a close approach to Earth in 2004.