7336 Saunders, provisional designation 1989 RS1, is a stony asteroid and near-Earth object of the Amor group, approximately 0.5 kilometers in diameter.
| Discovery [1] | |
|---|---|
| Discovered by | E. F. Helin |
| Discovery site | Palomar Obs. |
| Discovery date | 6 September 1989 |
| Designations | |
MPC designation | (7336) Saunders |
Named after | R. Stephen Saunders (JPL scientist)[2] |
Alternative designations | 1989 RS1 |
Minor planet category | NEO · Amor [1][3] |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 34.63 yr (12,647 days) |
| Aphelion | 3.4148 AU |
| Perihelion | 1.1956 AU |
Semi-major axis | 2.3052 AU |
| Eccentricity | 0.4813 |
Orbital period (sidereal) | 3.50 yr (1,278 days) |
Mean anomaly | 353.72° |
Mean motion | 0° 16m 53.76s / day |
| Inclination | 7.1958° |
Longitude of ascending node | 174.49° |
Argument of perihelion | 181.51° |
| Earth MOID | 0.1908 AU · 74.3 LD |
| Physical characteristics | |
| Dimensions | 0.467 km (derived)[4] |
Synodic rotation period | 6 h[5] 6.423±0.004 h[lower-alpha 1] |
Geometric albedo | 0.20 (assumed)[4] |
Spectral type | SMASS = Sq [1] · S [4] |
Absolute magnitude (H) | 18.0[5] · 18.45±0.2 (R)[lower-alpha 1] · 18.8[1] · 19.02±0.112[4][6] |
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]
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]
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.).[lower-alpha 1]
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]
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