Changes in R Leonis over Two Centuries: Period evolution and dust shell development
Abstract
The AAVSO-based historical light curve of the oxygen-rich Mira variable R Leonis is used to determine and analyse the properties of the star's maxima and minima. The pulsation period is found to have shortened by about 3 days over the past two centuries. Superimposed on the mean period are clear modulations on timescales of approximately 35 and 98 years. The depths of extrema show non-random behaviour: minima in particular display strong similarity in depth over extended intervals, with a mean depth difference of 0.26 magnitude for adjacent minima compared to a 0.38 magnitude difference for random pairs. Depth coherence persists for up to about 43 years. Examination of extrema depths over the full observational history of the star reveals gradual long-term changes, consistent with evolution of the circumstellar dust environment.
Keywords
Cite
@article{arxiv.2512.21296,
title = {Changes in R Leonis over Two Centuries: Period evolution and dust shell development},
author = {Mike Goldsmith},
journal= {arXiv preprint arXiv:2512.21296},
year = {2025}
}