Amplitude Modulation of Cepheid Radial Velocity Curves as a Systematic Source of Uncertainty for Baade-Wesselink Distances

TL;DR

This paper reports the discovery of amplitude modulation in Cepheid radial velocity curves, which could reduce systematic uncertainties in Baade-Wesselink distance measurements, improving their accuracy.

Contribution

It introduces a new systematic source of uncertainty in Cepheid distance measurements and suggests a method to improve accuracy.

Findings

Discovered amplitude modulation in four classical Cepheids

Identified a previously unconsidered systematic uncertainty

Potential to enhance the precision of Baade-Wesselink distances

Abstract

I report on the recent discovery of modulation in the radial velocity curves in four classical Cepheids. This discovery may enable significant improvements in the accuracy of Baade-Wesselink distances by revealing a not previously considered systematic source of uncertainty.