Qatar-2: A K dwarf orbited by a transiting hot Jupiter and a more massive companion in an outer orbit

TL;DR

This paper reports the discovery of Qatar-2b, a hot Jupiter transiting a K dwarf star, and identifies an additional outer companion, revealing a system architecture different from typical Kepler multi-planet systems.

Contribution

It presents the initial characterization of Qatar-2b and the detection of an outer companion, highlighting a new system architecture with a hot Jupiter and a distant massive companion.

Findings

Qatar-2b is a hot Jupiter with a 1.34-day orbit.

An outer companion with a period of about a year was detected.

The system architecture differs from Kepler's multi-transiting systems.

Abstract

We report the discovery and initial characterization of Qatar-2b, a hot Jupiter transiting a V = 13.3 mag K dwarf in a circular orbit with a short period, P_ b = 1.34 days. The mass and radius of Qatar-2b are M_p = 2.49 M_j and R_p = 1.14 R_j, respectively. Radial-velocity monitoring of Qatar-2 over a span of 153 days revealed the presence of a second companion in an outer orbit. The Systemic Console yielded plausible orbits for the outer companion, with periods on the order of a year and a companion mass of at least several M_j. Thus Qatar-2 joins the short but growing list of systems with a transiting hot Jupiter and an outer companion with a much longer period. This system architecture is in sharp contrast to that found by Kepler for multi-transiting systems, which are dominated by objects smaller than Neptune, usually with tightly spaced orbits that must be nearly coplanar.