Accounting for velocity jitter in planet search surveys

TL;DR

This paper introduces improved statistical algorithms for radial velocity data analysis in exoplanet searches that automatically account for velocity jitter, revealing potential systematic errors affecting planet detection reliability.

Contribution

The paper develops maximum likelihood-based algorithms that incorporate jitter estimation, enhancing accuracy in planetary parameter determination and identifying systematic errors in RV surveys.

Findings

Many RV surveys have systematic errors increasing jitter

The planet candidate HD74156 d may be a false detection

Algorithms improve reliability of exoplanet detection

Abstract

The role of radial velocity (RV) jitter in extrasolar planet search surveys is discussed. Based on the maximum likelihood principle, improved statistical algorithms for RV fitting and period search are developed. These algorithms incorporate a built-in jitter determination, so that resulting estimations of planetary parameters account for this jitter automatically. This approach is applied to RV data for several extrasolar planetary systems. It is shown that many RV planet search surveys suffer from periodic systematic errors which increase effective RV jitter and can lead to erroneous conclusions. For instance, the planet candidate HD74156 d may be a false detection made due to annual systematic errors.