(529366) 2009 WM1

(529366) 2009 WM₁, provisional designation 2009 WM₁, is a sub-kilometer asteroid and near-Earth object of the Apollo group, approximately 280 meters (920 feet) in diameter.^[4] After its discovery by the Catalina Sky Survey at the Catalina Station in Arizona, United States, this potentially hazardous asteroid was briefly listed at a Torino Scale of 1 and a cumulative Palermo Scale of −0.87.^[4] It was removed from the Sentry Risk Table on 26 June 2013.^[5]

(529366) 2009 WM₁

Discovery[1][2]
Discovered by	CSS
Discovery site	Catalina Stn.
Discovery date	17 November 2009
Designations
MPC designation	(529366) 2009 WM1
Alternative designations	2009 WM1
Minor planet category	NEO Apollo PHA[1][3]
Orbital characteristics[3]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 0
Observation arc	8.99 yr (3,283 d)
Aphelion	1.3798 AU
Perihelion	0.9810 AU
Semi-major axis	1.1804 AU
Eccentricity	0.1689
Orbital period (sidereal)	1.28 yr (468 d)
Mean anomaly	144.70°
Mean motion	0° 46m 6.6s / day
Inclination	25.768°
Longitude of ascending node	240.27°
Argument of perihelion	162.62°
Earth MOID	0.0001 AU (0.039 LD)
Physical characteristics
Mean diameter	280 m (est.)[4]
Mass	2.9×1010 kg[4]
Absolute magnitude (H)	20.4[1][3]

Numbering and naming

This minor planet was numbered by the Minor Planet Center on 18 May 2019 (M.P.C. 114667).^[6] As of 2019, it has not been named.^[1]

Orbit and classification

2009 WM₁ orbits the Sun at a distance of 0.98–1.38 AU once every 15 months (468 days; semi-major axis of 1.18 AU). Its orbit has an eccentricity of 0.17 and an inclination of 26° with respect to the ecliptic.^[3]

Even though 2009 WM₁ has an Earth MOID of 0.00009 AU (13,000 km; 8,400 mi), the orbit and future close approaches are well determined with an orbital uncertainty of 1.^[3]

On 23 November 2059, 2009 WM₁ will pass 0.0046 AU (690,000 km; 430,000 mi) from Earth.^[7] On 23 November 2199, it will make another close approach at a distance of 0.0005 AU (75,000 km; 46,000 mi) to 0.069 AU, but since it is a close approach and the exact distance in uncertain, future close approaches after 2199 are uncertain.^[7]

2014 passage

The 21 May 2014 Earth close approach of 0.3622 AU (54,180,000 km; 33,670,000 mi) should allow a refinement to the orbit.^[7] From 7 May 2014 until 2 June 2014 the asteroid will be brighter than apparent magnitude 20.^[8] The asteroid will come to opposition on 18 May 2014 when it will be up all night.^[8]