(242450) 2004 QY2

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(242450) 2004 QY2
Discovery [1][2]
Discovered by Siding Spring Srvy.
Discovery site Siding Spring Obs.
Discovery date 20 August 2004
MPC designation (242450) 2004 QY2
2004 QY2
Apollo · NEO · PHA[3][1]
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
1.0840 AU
Eccentricity 0.4773
1.13 yr (412 days)
0° 52m 23.88s / day
Inclination 37.026°
Earth MOID 0.0469 AU · 18.3 LD
Physical characteristics
Dimensions 2.914±0.084 km[4]
3.320 km[5]

(242450) 2004 QY2, provisional 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 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]

Orbit and classification[edit]

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[edit]

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[edit]

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[edit]

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[edit]

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


  1. ^ a b c d e "242450 (2004 QY2)". Minor Planet Center. Retrieved 19 January 2018. 
  2. ^ a b "MPEC 2004-Q27 : 2004 QY2 (K04Q02Y)". IAU Minor Planet Center. 2004-08-22. Retrieved 2012-06-17. 
  3. ^ a b c d e f g h "JPL Small-Body Database Browser: 242450 (2004 QY2)" (2016-04-01 last obs.). Jet Propulsion Laboratory. Retrieved 19 January 2018. 
  4. ^ a b c Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522Freely accessible. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. Retrieved 19 January 2018. 
  5. ^ a b Mainzer, A.; Bauer, J.; Cutri, R. M.; Grav, T.; Masiero, J.; Beck, R.; et al. (September 2014). "Initial Performance of the NEOWISE Reactivation Mission" (PDF). The Astrophysical Journal. 792 (1): 14. arXiv:1406.6025Freely accessible. Bibcode:2014ApJ...792...30M. doi:10.1088/0004-637X/792/1/30. Retrieved 19 January 2018. 
  6. ^ a b "List of the Potentially Hazardous Asteroids (PHAs)". Minor Planet Center. Retrieved 19 January 2018. 
  7. ^ "JPL Small-Body Database Search Engine: PHAs and H < 15 (mag)". JPL Solar System Dynamics. Retrieved 19 January 2018. 
  8. ^ "Major News about Minor Objects". hohmanntransfer. 22 August 2004. Retrieved 19 January 2018. 
  9. ^ "Sentry: Earth Impact Monitoring – Removed Objects". NASA/JPL CNEOS – Center for Near-Earth Object Studies. Retrieved 19 January 2018. 
  10. ^ a b "LCDB Data for (242450)". Asteroid Lightcurve Database (LCDB). Retrieved 19 January 2018. 
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 25 February 2018. 

External links[edit]