The CORALIE survey for southern extra-solar planets XI. The return of the giant planet orbiting HD192263

TL;DR

This study confirms the existence of a giant planet orbiting HD192263 through combined radial velocity, photometry, and bisector measurements, despite photometric signals that vary over time.

Contribution

The paper provides strong evidence for a planetary companion around HD192263 using multi-method observations, clarifying previous uncertainties.

Findings

Radial velocity signals are stable and indicative of a planet.

Photometric signals vary and are not linked to the planet.

A long-term trend suggests a possible additional companion.

Abstract

The presence of a planet around the K dwarf HD192263 was recently called into question by the detection of a periodic photometric signal with the same period as the one observed in radial velocity. In this paper, we investigate this possibility, using a combination of radial-velocity, photometry, and bisector measurements obtained simultaneously. The results show that while the observed radial-velocity variation is always very stable in phase, period, and amplitude, the photometric signal changes with time. The combined information strongly suggests that the observed radial-velocity variation is being produced by the presence of a planet, as firstly proposed. The photometric variations are either not connected to the planetary companion, or can eventually be induced by the interaction between the planet and the star. Finally, the radial-velocity data further show the presence of a long term trend, whose origin, still not clear, might be related to the presence of another companion to the system.