We conduct a rigorous examination of the nearby red supergiant Betelgeuse by drawing on
the synthesis of new observational data and three different modeling techniques. Our …

Long secondary periods (LSPs), observed in a third of pulsating red giant stars, are the only
unexplained type of large-amplitude stellar variability known at this time. Here we show that …

We present year-long, near-infrared (NIR) Hubble Space Telescope (HST) WFC3
observations of Mira variables in the water megamaser host galaxy NGC 4258. Miras are …

We examine a century of radial velocity, visual magnitude, and astrometric observations of
the nearest red supergiant, Betelgeuse, in order to reexamine the century-old assertion that …

Aims. We present a detailed long-term study of the single M6 III giant RZ Ari to obtain direct
and simultaneous measurements of the magnetic field, activity indicators, and radial velocity …

We briefly review the phenomenon of long secondary periods (LSPs) in red giants, and the
LSP variable stars classification introduced in the All-Sky Automated Survey for Supernovae …

Red giants are unstable to radial pulsation. About a third of them also show a long
secondary period, 5 to 10 times the pulsation period. The long secondary periods were …

We conducted a benchmarking analysis of the semi-regular pulsator and red supergiant
$\alpha $ Ori. In its dimming episode last 2020, our observational results include the binned …

We have used many decades of visual observations from the AAVSO International
Database, and the AAVSO time-series analysis package VSTAR, to study the long-term …

We have used AAVSO visual and photoelectric V data, and the AAVSO time-series package
VSTAR and the Lomb-Scargle time-series algorithm to determine improved pulsation …