7336 Saunders

7336 Saunders
Discovery [1]
Discovered byE. F. Helin
Discovery sitePalomar Obs.
Discovery date6 September 1989
(7336) Saunders
Named after
R. Stephen Saunders
(JPL scientist)[2]
1989 RS1
NEO · Amor[1][3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc34.63 yr (12,647 days)
Aphelion3.4148 AU
Perihelion1.1956 AU
2.3052 AU
3.50 yr (1,278 days)
0° 16m 53.76s / day
Earth MOID0.1908 AU · 74.3 LD
Physical characteristics
Dimensions0.467 km (derived)[4]
6 h[5]
6.423±0.004 h[a]
0.20 (assumed)[4]
SMASS = Sq[1] · S[4]
18.0[5] · 18.45±0.2 (R)[a] · 18.8[1] · 19.02±0.112[4][6]

7336 Saunders, provisional designation 1989 RS1, is a stony asteroid and near-Earth object of the Amor group, approximately 0.5 kilometers in diameter.

The asteroid was discovered on 6 September 1989, by American astronomer Eleanor Helin at Palomar Observatory in California, United States.[3] It was named for JPL-project scientist R. Stephen Saunders.[2]

Orbit and classification[]

Saunders orbits the Sun at a distance of 1.2–3.4 AU once every 3 years and 6 months (1,278 days). Its orbit has an eccentricity of 0.48 and an inclination of 7° with respect to the ecliptic.[1]

A first precovery was taken at the Australian Siding Spring Observatory in 1982, extending the body's observation arc by 7 years prior to its official discovery at Palomar.[3] It has a minimum orbital intersection distance with Earth of 0.1908 AU (28,500,000 km), which corresponds to 74.3 lunar distances.[4]

Physical characteristics[]

In the SMASS classification, Saunders is a Sq-type, which transitions from the common S-type to the Q-type asteroids.[1] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and derives a diameter of 467 meters, based on an absolute magnitude of 19.02.[4]


In October 1989, the first photometric observations of Saunders were made with the ESO 1-metre telescope at La Silla in Chile.[5] It gave a rotation period of 6 hours with a brightness variation of 0.3 magnitude (U=2). Another rotational lightcurve was obtained by Czech astronomer Petr Pravec at Ondřejov Observatory in August 2003, giving a period of 6.423±0.004 and an amplitude of 0.2 magnitude (U=n.a.).[a]


This minor planet was named in honor of JPL-project scientist R. Stephen Saunders (born 1940), director of the RPIF and head scientist of the Solar System Exploration Office. He worked on the Mars Surveyor 2001/03 program and on the Magellan spacecraft, that visited and mapped Venus in 1990.[2] The official naming citation was published by the Minor Planet Center on 26 July 2000 (M.P.C. 41028).[7]


  1. ^ a b c Pravec (2003): rotation period 6.423±0.004 hours with a brightness amplitude of 0.2 mag. Summary figures for (7336) Saunders at Collaborative Asteroid Lightcurve Link (CALL) and Pravec, P.; Wolf, M.; Sarounova, L. (2003)


  1. ^ a b c d e f g "JPL Small-Body Database Browser: 7336 Saunders (1989 RS1)" (2017-06-05 last obs.). Jet Propulsion Laboratory. Retrieved 22 June 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(7336) Saunders". Dictionary of Minor Planet Names – (7336) Saunders. Springer Berlin Heidelberg. p. 591. doi:10.1007/978-3-540-29925-7_6435. ISBN 978-3-540-00238-3.
  3. ^ a b c "7336 Saunders (1989 RS1)". Minor Planet Center. Retrieved 26 September 2016.
  4. ^ a b c d e f "LCDB Data for (7336) Saunders". Asteroid Lightcurve Database (LCDB). Retrieved 26 September 2016.
  5. ^ a b c Hoffmann, Martin; Rebhan, Helge; Neukum, Gerhard; Geyer, Edward H. (January 1993). "Photometric observations of four near-earth asteroids". Acta Astronomica. 43: 61–67. Bibcode:1993AcA....43...61H. ISSN 0001-5237. Retrieved 26 September 2016.
  6. ^ Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026. Retrieved 26 September 2016.
  7. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 26 September 2016.

External links[]