R. P. Kudritzki

TL;DR: In this article, the authors obtained a high quality ROSAT PSPC spectrum of the bright O4 f star ζ Pup and matched the observed X-ray spectrum (0.1 to 2.5 keV) under the assumption that the X-rays arise from shocks distributed throughout the wind.

TL;DR: In this article, the authors collected more than 1130 high-resolution optical spectra for more than 250 Galactic classical Cepheids and used them to estimate the variation of both surface gravity and microturbulent velocity along the pulsation cycle.

TL;DR: In this article, the authors analyse four extreme active galactic nuclei (AGN) transients to explore the possibility that they are caused by rare, high-amplitude microlensing events.

TL;DR: In this paper, the authors presented a sample of M31 beat Cepheids from the Pan-STARRS 1 PAndromeda campaign and used the relation between fundamental mode period and the ratio of fundamental to first overtone period to derive the metallicity at the position of the beat Cepsheids using the relations from the model of Buchler.