Comment on "Stellar activity masquerading as planets in the habitable zone of the M dwarf Gliese 581"

TL;DR

This paper critiques a previous claim that stellar activity explains the Doppler signals attributed to a planet candidate, emphasizing the need for more appropriate analysis methods in exoplanet detection.

Contribution

It highlights flaws in the previous analysis and advocates for improved techniques to distinguish stellar activity from planetary signals.

Findings

Previous analysis used incorrect periodogram methods

Inadequate tools can lead to false planet detections

Calls for more rigorous analysis in exoplanet studies

Abstract

Robertson et al.(Reports, July 25 2014, p440-444)(1) claimed that activity-induced variability is responsible for the Doppler signal of the proposed planet candidate GJ 581d. We point out that their analysis using periodograms of residual data is incorrect, further promoting inadequate tools. Since the claim challenges the viability of the method to detect exo-Earths, we urge for more appropriate analyses (see appendix).