| Minorplanet: | yes |
| 3169 Ostro | |
| Background: |
|
| Discovery Ref: |   |
| Discovered: | 4 June 1981 |
| Mpc Name: | (3169) Ostro |
| Alt Names: | 1981 LA |
| Named After: | Steven J. Ostro |
| Mp Category: | main-belt Hungaria  |
| Orbit Ref: |   |
| Epoch: | 4 September 2017 (JD 2458000.5) |
| Uncertainty: | 0 |
| Observation Arc: | 63.43 yr (23,166 days) |
| Perihelion: | 1.7652 AU |
| Semimajor: | 1.8918 AU |
| Eccentricity: | 0.0669 |
| Period: | 2.60 yr (950 days) |
| Mean Motion: | / day |
| Inclination: | 24.906° |
| Asc Node: | 96.376° |
| Arg Peri: | 32.622° |
| Dimensions: | km |
| Albedo: | |
| Spectral Type: | TS Xe B–V = 0.771 U–B = 0.306 |
| Abs Magnitude: | 12.73 |
3169 Ostro, provisional designation, is a Hungaria family asteroid from the innermost regions of the asteroid belt, approximately 5 kilometers in diameter.
The asteroid was discovered on 4 June 1981, by American astronomer Edward Bowell at Lowell's Anderson Mesa Station in Flagstaff, Arizona, and named after planetary scientist Steven J. Ostro at JPL.
Ostro is a member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun at a distance of 1.8–2.0 AU once every 2 years and 7 months (950 days). Its orbit has an eccentricity of 0.07 and an inclination of 25° with respect to the ecliptic.
In the Tholen and SMASS taxonomy, Ostro is classified as a TS-type and Xe-type asteroid, respectively. It has also been characterized as an E-type asteroid.
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Ostro measures 4.662 kilometers in diameter and its surface has an outstandingly high albedo of 0.960. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.5152 and a diameter of 5.27 kilometers with an absolute magnitude of 12.73.
In May 2012, a rotational lightcurve of Ostro was obtained from photometric observations by American astronomer Brian Warner. Lightcurve analysis gave a well-defined rotation period of 6.503 hours with a brightness amplitude of 0.79 magnitude .
This minor planet was named after American planetary scientist Steven J. Ostro at the Jet Propulsion Laboratory of the California Institute of Technology. The approved naming citation was published by the Minor Planet Center on 14 April 1987 .