Notations such as Kepler 1708b-i can also be seen.[1] Kepler-1708b I is the second exomoon candidate, after Kepler-1625b I.[2]
Discovery
A survey of 70 cooler giant planets potentially hosting exomoons, discovered by the Kepler space telescope through observation of transits, was conducted; only Kepler-1708b was named as a candidate for having satellites. A paper reporting the possible discovery of Kepler-1708b I was submitted to arXiv on January 12, 2022. The false positive rate for Kepler-1708b I is only about 1%, with an even lower probability that the alleged satellite signal may be due to an unknown exoplanet other than Kepler-1708b orbiting around Kepler-1708. Although there is no evidence that Kepler-1708b I is not an exomoon at this time, it is still in the candidate stage, and future follow-up observations are required to confirm its existence. Additional Kepler-1708b I transit observations and transit-timing variations may be observable if future observations are made by the Hubble Space Telescope, James Webb Space Telescope, PLATO, etc. The last transit occurred on March 24, 2023.[1]
Characteristics
Kepler-1708b I is said to be a mini-Neptune or possibly a super-Earth with a radius of about 2.6 Earth radii. This is a much smaller size than Kepler-1625b I. Kepler-1708b I orbits at a distance of 740,000 kilometres from Kepler-1708b, with a period of about 4.6 days, in the same plane as the planet's orbit around the star.[1]
