9524 O'Rourke

9524 O'Rourke
Discovery [1]
Discovered byS. J. Bus
Discovery siteSiding Spring Obs.
Discovery date2 March 1981
(9524) O'Rourke
Named after
Laurence O'Rourke
(ESAC researcher)[2]
1981 EJ5 · 1975 NU
main-belt · (inner)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc41.90 yr (15,305 days)
Aphelion2.6928 AU
Perihelion1.7027 AU
2.1978 AU
3.26 yr (1,190 days)
0° 18m 9s / day
Physical characteristics
Dimensions2.920±0.662 km[3]

9524 O'Rourke, provisionally designated 1981 EJ5, is an asteroid from the inner regions of the asteroid belt, approximately 3 kilometers in diameter. It was discovered on 2 March 1981, by American astronomer Schelte Bus at the Siding Spring Observatory in New South Wales, Australia. The asteroid was named after Laurence O'Rourke, a researcher at the European Space Astronomy Centre.[2]

Orbit and classification[]

O'Rourke orbits the Sun in the inner main-belt at a distance of 1.7–2.7 AU once every 3 years and 3 months (1,190 days). Its orbit has an eccentricity of 0.23 and an inclination of 5° with respect to the ecliptic.[1] It was first observed as 1975 NU at Crimea–Nauchnij in 1975, extending the asteroid's observation arc by 6 years prior to its official discovery observation.[2]

Physical characteristics[]

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid measures 2.920 kilometers in diameter and its surface has an albedo of 0.273.[3]

As of 2017, O'Rourke's spectral type, as well as its rotation period and shape remain unknown.[1][4]


This minor planet was named after Laurence O'Rourke (born 1970), a researcher at the European Space Astronomy Centre in Madrid, Spain, and a coordinator of ESA's Rosetta mission.[2][5] The approved naming citation was published by the Minor Planet Center on 12 July 2014 (M.P.C. 89078).[6]


  1. ^ a b c d e "JPL Small-Body Database Browser: 9524 O'Rourke (1981 EJ5)" (2017-06-05 last obs.). Jet Propulsion Laboratory. Retrieved 22 June 2017.
  2. ^ a b c d "9524 O'Rourke (1981 EJ5)". Minor Planet Center. Retrieved 10 March 2017.
  3. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 10 March 2017.
  4. ^ "LCDB Data for (9524) O'Rourke". Asteroid Lightcurve Database (LCDB). Retrieved 10 March 2017.
  5. ^ "Asteroids Named After ESA Rosetta Scientists". ESA. Retrieved 18 August 2014.
  6. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 10 March 2017.

External links[]