|Discovered by||C. H. F. Peters, 1879|
|Discovery date||21 March 1879|
|Epoch 31 July 2016 (JD 2457600.5)|
|Uncertainty parameter 0|
|Observation arc||136.76 yr (49950 d)|
|Aphelion||3.2386 AU (484.49 Gm)|
|Perihelion||1.9930 AU (298.15 Gm)|
|2.6158 AU (391.32 Gm)|
|4.23 yr (1545.3 d)|
|0° 13m 58.692s / day|
|Earth MOID||0.986917 AU (147.6407 Gm)|
|Jupiter MOID||2.15988 AU (323.113 Gm)|
|15.679 h (0.6533 d)|
Prokne (minor planet designation: 194 Prokne) is a main-belt asteroid that was discovered by German-American astronomer C. H. F. Peters on March 21, 1879, in Clinton, New York, and named after Procne, the sister of Philomela in Greek mythology. Stellar occultations by Prokne have been observed twice, in 1984 from Italy and again in 1999 from Iowa (United States).
Observations from the W. M. Keck Observatory show the asteroid to be around 151 km across, with a size ratio of 1.13±0.06 between the major and minor axes. For comparison, observations by the IRAS observatory gave a diameter of 164 km. The spectrum matches a classification of a C-type asteroid, indicating it has a primitive carbonaceous composition. Judging from radar data, the near surface solid density of the asteroid is 3.6+1.1
−0.9 g cm−3.
Based upon a light curve that was generated from photometric observations of this asteroid at Pulkovo Observatory, it has a rotation period of 15.679±0.001 hours and varies in brightness by 0.16±0.02 in magnitude.