Searching for p-modes in MOST Procyon data: Another view

TL;DR

This study reanalyzes MOST satellite data of Procyon to investigate the presence of p-modes, highlighting how instrumental effects can mimic signals and finding no convincing evidence of p-modes in the data.

Contribution

It demonstrates the importance of accounting for instrumental effects in asteroseismic data analysis and provides a revised interpretation of Procyon's oscillation signals.

Findings

No convincing evidence of p-modes in the data

Instrumental effects can produce apparent signals

Reinterpretation of excess power near p-mode frequencies

Abstract

Photometry of Procyon obtained by the MOST satellite in 2004 has been searched for p modes by several groups, with sometimes contradictory interpretations. We explore two possible factors that complicate the analysis and may lead to erroneous reports of p modes in these data. Two methods are used to illustrate the role of subtle instrumental effects in the photometry: time-frequency analysis, and a search for regularly spaced peaks in a Fourier spectrum based on the echelle diagramme approach. We find no convincing evidence of a p-mode signal in the MOST Procyon data. We can account for an apparent excess of power close to the p-mode frequency range and signs of structure in an echelle diagramme in terms of instrumental effects.