Astronomy:(152680) 1998 KJ9
| Discovery[1] | |
|---|---|
| Discovered by | LINEAR (704) 1.0-m Reflector |
| Discovery site | Lincoln Lab's ETS |
| Discovery date | 27 May 1998 |
| Designations | |
| (152680) 1998 KJ9 | |
| Minor planet category | NEO · PHA · Apollo[2] |
| Orbital characteristics[2] | |
| Epoch 13 January 2016 (JD 2457400.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 7706 days (21.10 yr) |
| |{{{apsis}}}|helion}} | 2.3742 astronomical unit|AU (355.18 Gm) (Q) |
| |{{{apsis}}}|helion}} | 0.52125 AU (77.978 Gm) (q) |
| 1.4477 AU (216.57 Gm) (a) | |
| Eccentricity | 0.63995 (e) |
| Orbital period | 1.74 yr (636.25 d) |
| Mean anomaly | 6.2670° (M) |
| Mean motion | 0° 33m 56.952s / day (n) |
| Inclination | 10.932° (i) |
| Longitude of ascending node | 98.675° (Ω) |
| 259.95° (ω) | |
| Earth MOID | 0.00552 AU (826,000 km) |
| Physical characteristics | |
| Dimensions | ~500 meters[3] |
| Mass | 7.87×1010 kg[4] |
| Absolute magnitude (H) | 19.4[2] |
(152680) 1998 KJ9 is a sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group.[2] Based on absolute magnitude, it is the third largest asteroid known to have passed closer than the Moon.[5]
Description
It was discovered on 27 May 1998, by astronomers of the Lincoln Near-Earth Asteroid Research (LINEAR) at Lincoln Laboratory's ETS near Socorro, New Mexico, at an apparent magnitude of 17.6 using a 1.0-meter (39 in) reflector.[1] It was tracked through 9 June 1998.[6] It was recovered on 28 December 2003 which extended the observation arc by 5 years.[7] Two precovery images from January 1990 extended the observation arc by 8 years.[6]
Based on an absolute magnitude of 19.4,[2] the asteroid has an estimated diameter of about 500 metres (1,600 ft).[3] (152680) 1998 KJ9 is noted for a close approach to the Earth on 31 December 1914 at a distance of 0.00155 astronomical unit|AU (232,000 km; 144,000 mi).[8] 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.[9]
References
- ↑ 1.0 1.1 "MPEC 1998-K31 : 1998 KJ9". IAU Minor Planet Center. 1998-05-29. https://www.minorplanetcenter.net/iau/mpec/J98/J98K31.html. Retrieved 2011-11-15. (J98K09J)
- ↑ 2.0 2.1 2.2 2.3 2.4 "JPL Small-Body Database Browser: 152680 (1998 KJ9)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=1998KJ9. Retrieved 7 April 2016.
- ↑ 3.0 3.1 "Near Earth Asteroids (NEAs)". International Astronomical Union. 13 October 2011. http://neo.ssa.esa.int/web/guest/neo-chronology. Retrieved 2011-10-30.
- ↑ "Asteroid General Data - 1998 KJ9 (152680)". Catalogue of the Solar System Small Bodies Orbital Evolution. http://smallbodies.ru/en/asteroids/info/general/1998_KJ9/. Retrieved 2011-11-15.
- ↑ NEO Earth Close Approaches @ JPL CNEOS
Select "Nominal dist <= 1 LD", "Past only", Sort by "H (mag)" - ↑ 6.0 6.1 "(152680) = 1998 KJ9 Orbit". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=152680. Retrieved 2013-09-24.
- ↑ "MPEC 2003-Y87 : 1998 KJ9". IAU Minor Planet Center. 2003-12-29. https://www.minorplanetcenter.net/iau/mpec/J98/J98K31.html. Retrieved 2013-09-24.
- ↑ "JPL Close-Approach Data: 152680 (1998 KJ9)". https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=1998KJ9;cad=1#cad. Retrieved 2011-11-15.
- ↑ "1998KJ9 Ephemerides for 31 December 1914". NEODyS (Near Earth Objects - Dynamic Site). http://newton.spacedys.com/neodys/index.php?pc=1.1.3.1&n=152680&oc=500&y0=1914&m0=12&d0=31&h0=0&mi0=0&y1=1915&m1=1&d1=2&h1=0&mi1=0&ti=1&tiu=hours. Retrieved 2011-11-15.
External links
- (152680) 1998 KJ9 at NeoDyS-2, Near Earth Objects—Dynamic Site
- Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
- (152680) 1998 KJ9 at ESA–space situational awareness
- (152680) 1998 KJ9 at the JPL Small-Body Database
| Preceded by |
Large NEO Earth close approach (inside the orbit of the Moon) 31 December 1914 |
Succeeded by (163132) 2002 CU11 |
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