| Minorplanet: | yes |
| Background: |
|
| 103 Hera | |
| Discovered: | 7 September 1868 |
| Mpc Name: | (103) Hera |
| Alt Names: | A868 RA, 1927 CV 1950 CM |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Semimajor: | 2.70109AU |
| Perihelion: | 2.48175AU |
| Aphelion: | 2.92042abbr=onNaNabbr=on |
| Eccentricity: | 0.0812034 |
| Period: | 4.44 yr (1621.5 d) |
| Inclination: | 5.41957° |
| Asc Node: | 136.186° |
| Arg Peri: | 188.361° |
| Avg Speed: | 18.09 km/s |
| Mass: | 7.9 kg |
| Surface Grav: | 0.0255 m/s² |
| Escape Velocity: | 0.0482 km/s |
| Rotation: | 23.74abbr=onNaNabbr=on 0.9892 d |
| Abs Magnitude: | 7.66 |
| Mean Motion: | / day |
| Observation Arc: | 144.99 yr (52958 d) |
| Uncertainty: | 0 |
| Moid: | 1.46898AU |
| Jupiter Moid: | 2.32392AU |
| Tisserand: | 3.356 |
103 Hera is a moderately large main-belt asteroid with an orbital period of 1621.5days. It was discovered by Canadian-American astronomer James Craig Watson on September 7, 1868, and named after Hera, queen and fifth in power of the Olympian gods in Greek mythology. This is a stony S-type asteroid with a silicate surface composition.
Photometric observations made in 2010 at the Organ Mesa Observatory at Las Cruces, New Mexico, and the Hunters Hill Observatory at Ngunnawal, Australian Capital Territory, give a synodic rotation period of . The bimodal light curve shows a maximum brightness variation of 0.45 ± 0.03 in magnitude.
Measurements made with the IRAS observatory give a diameter of and a geometric albedo of . By comparison, the MIPS photometer on the Spitzer Space Telescope gives a diameter of and a geometric albedo of . When the asteroid was observed occulting a star, the chords showed a diameter of .