Radial velocities and transit times for KOI 4

However, a major challenge has been the confirmation of Kepler planet candidates, many of which still await confirmation. One of the most enigmatic examples is KOI 4.01, Kepler's first discovered planet candidate detection (as KOI 1.01, 2.01, and 3.01 were known prior to launch).

Here we present the confirmation and characterization of KOI 4.01 (now Kepler-1658), using a combination of asteroseismology and radial velocities. Kepler-1658 is a massive, evolved subgiant (M_*_=1.45+/-0.06 M_{sun}_, R_*_=2.89+/-0.12 R_{sun}_) hosting a massive (M_p_=5.88+/-0.47 M_J_, R_p_=1.07+/-0.05 R_J_) hot Jupiter that orbits every 3.85 days. Kepler-1658 joins a small population of evolved hosts with short-period (~<100 days) planets and is now the closest known planet in terms of orbital period to an evolved star.