| b>101 Helena |
| bgcolor="#ffc0c0" colspan="2" | Orbital characteristics 1 |
| a href="/encyclopedia/Orbit" title="Orbit">Orbit type | Main belt |
| a href="/encyclopedia/Semimajor-axis" title="Semimajor axis">Semimajor axis | 2.583 AU |
| a href="/encyclopedia/Perihelion" title="Perihelion">Perihelion distance | 2.218 AU |
| a href="/encyclopedia/Aphelion" title="Aphelion">Aphelion distance | 2.947 AU |
| a href="/encyclopedia/Orbital-period" title="Orbital period">Orbital period | 4.15 years |
| a href="/encyclopedia/Inclination" title="Inclination">Inclination | 10.20° |
| a href="/encyclopedia/Eccentricity" title="Eccentricity">Eccentricity | 0.141 |
| bgcolor="#ffc0c0" colspan="2" | Physical characteristics 1 |
| a href="/encyclopedia/Diameter" title="Diameter">Diameter | 65.8 km |
| a href="/encyclopedia/Rotation-period" title="Rotation period">Rotation period | 23.08 hours |
| a href="/encyclopedia/Spectral-class" title="Spectral class">Spectral class | S |
| a href="/encyclopedia/Absolute-magnitude" title="Absolute magnitude">Abs. magnitude | 8.33 |
| a href="/encyclopedia/Albedo" title="Albedo">Albedo 4 | 0.190 |
| bgcolor="#ffc0c0" colspan="2" | History 2 |
| iscoverer | J. C. Watson, 1868 |