(9903) 1997 NA1

9903 Leonhardt
Orbit of Leonhardt (blue), with the inner planets and Jupiter (outermost)
Discovery [1]
Discovered byP. G. Comba
Discovery sitePrescott Obs.
Discovery date4 July 1997
(9903) Leonhardt
Named after
Gustav Leonhardt
(conductor and harpsichordist)[2]
1997 NA1 · 1976 UG6
main-belt[1][3] · (outer)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc40.43 yr (14,767 days)
Aphelion3.8232 AU
Perihelion2.3527 AU
3.0880 AU
5.43 yr (1,982 days)
0° 10m 53.76s / day
Physical characteristics
Dimensions8.499±0.240 km[4]
17.8 km[5]

9903 Leonhardt, provisional designation 1997 NA1, is a dark asteroid from the outer region of the asteroid belt, approximately 10 kilometers in diameter.

The asteroid was discovered on 4 July 1997, by American amateur astronomer Paul Comba at Prescott Observatory in Arizona, United States.[3] It was named after Dutch keyboard player Gustav Leonhardt.[2]

Orbit and classification[]

Leonhardt orbits the Sun in the outer main-belt at a distance of 2.4–3.8 AU once every 5 years and 5 months (1,982 days). Its orbit has an eccentricity of 0.24 and an inclination of 2° with respect to the ecliptic.[1]

It was first identified as 1976 UG6 at Kiso Observatory in 1976, extending the body's observation arc by 21 years prior to its official discovery observation at Prescott.[3]

Physical characteristics[]

Diameter and albedo[]

According to the surveys carried out by the Infrared Astronomical Satellite IRAS and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Leonhardt measures 17.8 and 8.499 kilometers in diameter, respectively.[4][5] WISE/NEOWISE also gives an albedo of 0.042 for the body's surface.[4] It has an absolute magnitude of 14.5.[1]


As of 2017, the asteroid's rotation period and shape remain unknown.[1][6]


This minor planet was named for Gustav Leonhardt (1928–2012), a Dutch conductor and harpsichordist, who founded the Leonhardt Baroque Ensemble. He was known for his many international concert tours and for his large number of recorded baroque works.[2] The official naming citation was published by the Minor Planet Center on 2 April 1999 (M.P.C. 34356).[7]

The main-belt asteroid 12637 Gustavleonhardt, discovered during the second Palomar–Leiden Trojan survey campaign in 1973, is also named in his honor.[8]


  1. ^ a b c d e f g "JPL Small-Body Database Browser: 9903 Leonhardt (1997 NA1)" (2017-03-28 last obs.). Jet Propulsion Laboratory. Retrieved 22 June 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(9903) Leonhardt". Dictionary of Minor Planet Names – (9903) Leonhardt. Springer Berlin Heidelberg. p. 712. doi:10.1007/978-3-540-29925-7_7742. ISBN 978-3-540-00238-3.
  3. ^ a b c "9903 Leonhardt (1997 NA1)". Minor Planet Center. Retrieved 17 March 2017.
  4. ^ a b c d 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 17 March 2017.
  5. ^ a b Tedesco E.F.; Noah P.V.; Noah M.; Price S.D. "The supplemental IRAS minor planet survey (SIMPS)".
  6. ^ "LCDB Data for (9903) Leonhardt". Asteroid Lightcurve Database (LCDB). Retrieved 17 March 2017.
  7. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 17 March 2017.
  8. ^ "12637 Gustavleonhardt (1053 T-2)". Minor Planet Center. Retrieved 17 March 2017.

External links[]