Final answer:
The most detected size planets from Kepler data as of early 2013 were small to medium-sized planets, specifically labeled as super-Earths and mini-Neptunes, which range from 1.4 to 4 times the size of Earth.
Step-by-step explanation:
The main answer to the question of which size planets were most detected from the orbital periods and radii of all planet candidates identified from Kepler data as of early 2013 is: small to medium-sized planets, specifically those with radii between 1.4 and 2.8 times that of Earth, known as super-Earths, as well as those between 2.8 and 4 times that of Earth, often called mini-Neptunes. The discoveries of the Kepler mission showed a significant number of these super-Earths and mini-Neptunes, which do not have analogs in our own solar system, indicating a bias in the earlier Doppler observations which detected more massive, Jupiter-sized planets due to ease of discovery.Explanation in more than 100 words: The data collected by the Kepler telescope has shown that larger planets and those with shorter orbital periods are easier to detect due to limitations in observational technology and mission duration. Kepler's sensitivity was such that it could mostly detect planets with orbital periods less than 400 days and larger than Mars. Despite these constraints, Kepler was particularly successful in discovering a vast number of Earth-sized and slightly larger planets, suggesting that nearly one such planet exists per star for stars with planets of orbital periods less than 2 years.Conclusion: Based on the data from Kepler discoveries, the most common planet sizes of are those of Earths and super-Earths, indicating a prevalence of smaller to medium-sized planets in contrast to the larger, gas giants initially discovered by Doppler techniques. These findings underscore the diversity of planetary systems beyond our own and the influence of observational methods on our understanding of planetary prevalence.