| Orbital characteristics 1 | |
|---|---|
| Orbit type | Main belt |
| Semimajor axis | 2.448 AU |
| Perihelion distance | 2.052 AU |
| Aphelion distance | 2.845 AU |
| Orbital period | 3.83 years |
| Inclination | 3.21° |
| Eccentricity | 0.162 |
| Physical characteristics 1 | |
| Diameter | 45.5 km |
| Rotation period | 10.103 hours |
| Spectral class 5 | S |
| Abs. magnitude | 8.75 |
| Albedo 4 | 0.270 |
| History 2 | |
| Discoverer | J. Perrotin, 1874 |
138 Tolosa (to-loe'-za, Latin Tolōsa) is a brightly coloured, stony Main belt asteroid.
It was discovered by Henri Joseph Perrotin on May 19 1874 and named after the Latin for Toulouse, France.