(242450) 2004 QY2

(242450) 2004 QY₂ (prov. designation: 2004 QY₂) is an asteroid on an eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 3 kilometers (2 miles) in diameter. It was discovered on 20 August 2004 by the Siding Spring Survey at an apparent magnitude of 16.5 using the 0.5-metre (20 in) Uppsala Southern Schmidt Telescope.^[2] It is one of the largest potentially hazardous asteroids known to exist.^[6]

(242450) 2004 QY₂

Discovery[1][2]
Discovered by	SSS
Discovery site	Siding Spring Obs.
Discovery date	20 August 2004
Designations
MPC designation	(242450) 2004 QY2
Alternative designations	2004 QY2
Minor planet category	Apollo · NEO · PHA[1][3]
Orbital characteristics[3]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	11.61 yr (4,242 days)
Aphelion	1.6013 AU
Perihelion	0.5666 AU
Semi-major axis	1.0840 AU
Eccentricity	0.4773
Orbital period (sidereal)	1.13 yr (412 days)
Mean anomaly	123.98°
Mean motion	0° 52m 23.88s / day
Inclination	37.026°
Longitude of ascending node	295.31°
Argument of perihelion	104.96°
Earth MOID	0.0469 AU · 18.3 LD
Physical characteristics
Mean diameter	2.914±0.084 km[4] 3.320 km[5]
Geometric albedo	0.274±0.044[4]
Absolute magnitude (H)	14.7[1][3]

Orbit and classification

2004 QY₂ orbits the Sun at a distance of 0.6–1.6 AU once every 14 months (412 days; semi-major axis of 1.08 AU). Its orbit has an eccentricity of 0.48 and an inclination of 37° with respect to the ecliptic.^[3] The body's observation arc begins with its official discovery observation at Siding Spring.^[1]

The object is a member of the Apollo asteroids, the largest subgroup of near-Earth asteroids which cross the orbit of Earth. Unlike many other members of this dynamical group, 2004 QY₂ is not a Mars-crosser, as its aphelion is too small to cross the orbit of the Red Planet at 1.66 AU.^[3]

Close approaches

With an absolute magnitude of 14.7, 2004 QY₂ is one of the brightest potentially hazardous asteroids ever discovered (see PHA-list).^[6][7] It has an Earth minimum orbital intersection distance of 0.0469 AU (7,020,000 km), which translates into 18.3 lunar distances.^[3] On 29 July 2012, it passed Earth at a distance of 0.4314 AU (64,540,000 km; 40,100,000 mi).^[3]

Sentry Risk Table

Due to its originally estimated size of 5.5 kilometers, 2004 QY₂ was one of the largest objects to appear on the Sentry Risk Table.^[8] It was removed from the Sentry Risk Table on 25 August 2004.^[9]

Physical characteristics

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, 2004 QY₂ has an albedo of 0.274, and it measures 2.914 and 3.320 kilometers in diameter, respectively.^[4][5]

As of 2018, no rotational lightcurve of 2004 QY₂ has been obtained from photometric observations. The body's rotation period, shape and spin axis remain unknown.^[10] In addition, the body's spectral type has never been assessed.^[3][10]

Numbering and naming

This minor planet was numbered by the Minor Planet Center on 26 June 2006.^[11] As of 2018, it has not been named.^[1]