2 papers
astro-ph.SR2025
The elderly among the oldest: new evidence for extremely metal-poor RR Lyrae stars
Valentina D'Orazi, Vittorio F. Braga, Giuseppe Bono +21
We performed a detailed spectroscopic analysis of three extremely metal-poor RR Lyrae stars, exploring uncharted territories at these low metallicities for this class of stars. Usi…
astro-ph.SR2024
Period modulations of the long secondary periods on the AGB stars
Masaki Takayama
30--50 of the luminous pulsating red-giant stars show light variations of a longer period than the pulsation periods. Those periods are called long secondary periods (LSP).…