High-precision measurements challenge our understanding of Cepheids

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

"Classical Cepheids" are a type of pulsating star that rhythmically brighten and dim over time. These pulsations help astronomers measure vast distances across space, which makes Cepheids crucial "standard candles" that help us understand the size and scale of our universe.

Despite their importance, studying Cepheids is challenging. Their pulsations and potential interactions with companion stars create complex patterns that are difficult to measure accurately. Different instruments and methods used over the years have led to inconsistent data, complicating our understanding of these stars.

"Tracing Cepheid pulsations with high-definition velocimetry gives us insights into the structure of these stars and how they evolve," says Richard I. Anderson, an astrophysicist at EPFL. "In particular, measurements of the speed at which the stars expand and contract along the line of sight—so-called radial velocities—provide a crucial counterpart to precise brightness measurements from space. However, there has been an urgent need for high-quality radial velocities because they are expensive to collect and because few instruments are capable of collecting them."

Leave a Comment