K2-30b and K2-34b: two inflated hot-Jupiters around Solar-type stars

TL;DR

This paper reports the discovery and characterization of two inflated hot-Jupiters, K2-30b and K2-34b, orbiting bright, main-sequence stars, using space-based transit data and ground-based radial velocity follow-up.

Contribution

It presents the first detailed characterization of two new hot-Jupiters discovered by K2, including their physical properties and potential for further atmospheric and obliquity studies.

Findings

Both planets are bloated hot-Jupiters with radii over 1.2 R_Jup.

They orbit relatively bright, slow-rotating stars, suitable for Rossiter-MacLaughlin effect measurements.

The systems are promising for atmospheric characterization.

Abstract

We report the discovery of the two hot-Jupiters K2-30b and K2-34b. The two planets were detected transiting their main-sequence star with periods $\sim$ 4.099 and $\sim$ 2.996 days, in campaigns 4 and 5 of the extension of the Kepler mission, K2. Subsequent ground-based radial velocity follow-up with SOPHIE, HARPS-N and CAFE, established the planetary nature of the transiting objects. We analyzed the transit signal, radial velocity and spectral energy distributions of the two systems to characterize their properties. Both planets (K2-30b and K2-34b) are bloated hot-Jupiters (1.25 $R_{\rm Jup}$ and 1.33 $R_{\rm Jup}$) around relatively bright (V =13.5 and V=11.5), slow rotating main-sequence (G8 and F9) stars. Thus, these systems are good candidates for detecting the Rossiter-MacLaughlin effect to measure their obliquity and for atmospheric studies.