Three small transiting planets around the M dwarf host star LP 358-499

TL;DR

This paper reports the discovery of three small transiting planets around the low-mass M dwarf star LP 358-499 using Kepler-K2 data, highlighting their potential for future atmospheric characterization.

Contribution

First detection of three small transiting planets around LP 358-499, with additional candidate, providing targets for follow-up studies and atmospheric analysis.

Findings

Three confirmed planets with orbital periods of 3, 4.9, and 11 days.

Planet candidate at 26.6 days possibly in habitable zone.

Innermost planet likely rocky based on transit and stellar data.

Abstract

We report on the detection of three transiting small planets around the low-mass star LP 358-499 (K2-133), using photometric data from the Kepler-K2 mission. Using multiband photometry, we determine the host star to be an early M dwarf with an age likely older than a Gigayear. The three detected planets K2-133 b, c, and d have orbital periods of ca. 3, 4.9 and 11 days and transit depths of ca. 700, 1000 and 2000 ppm, respectively. We also report a planetary candidate in the system (EPIC 247887989.01) with a period of 26.6 days and a depth of ca. 1000 ppm, which may be at the inner edge of the stellar habitable zone, depending on the specific host star properties. Using the transit parameters and the stellar properties, we estimate that the innermost planet may be rocky. The system is suited for follow-up observations to measure planetary masses and JWST transmission spectra of planetary atmospheres.