| Minorplanet: | yes |
| Background: |
|
| 309 Fraternitas | |
| Discovered: | 6 April 1891 |
| Mpc Name: | (309) Fraternitas |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Eccentricity: | 0.11512 |
| Period: | 4.35 yr (1588.7 d) |
| Inclination: | 3.71999° |
| Asc Node: | 356.574° |
| Arg Peri: | 310.477° |
| Rotation: | 22.398abbr=onNaNabbr=on |
| Abs Magnitude: | 10.7 |
| Mean Motion: | / day |
| Orbit Ref: | [1] |
| Observation Arc: | 125.03 yr (45667 d) |
| Uncertainty: | 0 |
309 Fraternitas is a typical Main belt asteroid.[2] It was discovered by Johann Palisa on 6 April 1891 in Vienna. The asteroid name is Latin for 'fraternity'; it was so named in order to commemorate the 25th anniversary of the Maturitätsprüfung Fraternity.
This minor planet is orbiting the Sun at a distance of with an orbital eccentricity (ovalness) of 0.115 and a period of . The orbital plane is inclined at an angle of 3.72° of the ecliptic. Analysis of the asymmetric bimodal light curve of the asteroid from photometric data collected during 2014 provide a rotation period of with a brightness variation of in magnitude.