(152680) 1998 KJ9

(152680) 1998 KJ9
Discovery[1]
Discovered by LINEAR (704)
1.0-m Reflector
Discovery date 27 May 1998
Designations
MPC designation (152680) 1998 KJ9
Apollo NEO,
PHA[2]
Orbital characteristics[2]
Epoch 2011-Aug-27
(Uncertainty=0)[2]
Aphelion 2.3743 AU (Q)
Perihelion 0.52157 AU (q)
1.4479 AU (a)
Eccentricity 0.63978
1.74 yr
181.06° (M)
Inclination 10.932°
98.712°
259.92°
Physical characteristics
Dimensions ~500 meters[3]
Mass 7.87×1010 kg[4]
19.4[2]

    (152680) 1998 KJ9 is a near-Earth asteroid and potentially hazardous object.[2] It has a well determined orbit with an excellent observation arc of 21 years and an Uncertainty Parameter of 0.[2]

    It was discovered on 27 May 1998 by the Lincoln Near-Earth Asteroid Research (LINEAR) at an apparent magnitude of 17.6 using a 1.0-meter (39 in) reflector.[1] It was tracked through 9 June 1998.[5] It was recovered on 28 December 2003 which extended the observation arc by 5 years.[6] Two precovery images from January 1990 extended the observation arc by 8 years.[5]

    Based on an absolute magnitude of 19.4,[2] the asteroid has an estimated diameter of about 500 metres (1,600 ft).[3] 1998 KJ9 is noted for a close approach to the Earth on 31 December 1914 at a distance of 0.00155 AU (232,000 km; 144,000 mi).[7] It is one of the largest objects known to have come inside the orbit of the moon. During the 1914 close approach the asteroid reached about apparent magnitude 7.7.[8]

    References

    1. ↑ 1.0 1.1 "MPEC 1998-K31 : 1998 KJ9". IAU Minor Planet Center. 1998-05-29. Retrieved 2011-11-15. (J98K09J)
    2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 "JPL Small-Body Database Browser: 152680 (1998 KJ9)" (last observation: 2011-02-06; arc: 21.1 years). Jet Propulsion Laboratory. Retrieved 2011-11-15.
    3. ↑ 3.0 3.1 "Near Earth Asteroids (NEAs)" (Version 20.1). International Astronomical Union. 13 October 2011. Retrieved 2011-10-30.
    4. ↑ "Asteroid General Data - 1998 KJ9 (152680)". Catalogue of the Solar System Small Bodies Orbital Evolution. Retrieved 2011-11-15.
    5. ↑ 5.0 5.1 "(152680) = 1998 KJ9 Orbit" (2011-02-06; arc=7706 days). Minor Planet Center. Retrieved 2013-09-24.
    6. ↑ "MPEC 2003-Y87 : 1998 KJ9". IAU Minor Planet Center. 2003-12-29. Retrieved 2013-09-24.
    7. ↑ "JPL Close-Approach Data: 152680 (1998 KJ9)" (last observation: 2011-02-06; arc: 21.1 years). Retrieved 2011-11-15.
    8. ↑ "1998KJ9 Ephemerides for 31 December 1914". NEODyS (Near Earth Objects - Dynamic Site). Retrieved 2011-11-15.

    External links

    Preceded by
    		 Large NEO Earth close approach
    (inside the orbit of the moon)
    31 December 1914     		Succeeded by
    (163132) 2002 CU11