We present a review of UV observations of massive stars and their analysis. We discuss O
stars, luminous blue variables, and Wolf–Rayet stars. Because of their effective temperature …

Doppler spectroscopy is a powerful tool for discovering and characterizing exoplanets. For
decades, the standard approach to extracting radial velocities (RVs) has been to cross …

ABSTRACT Eta Carinae (η Car) is an extremely massive binary system in which rapid
spectrum variations occur near periastron. Most notably, near periastron the He ii λ4686 line …

Context. The mass loss from massive stars is not understood well. η Carinae is a unique
object for studying the massive stellar wind during the luminous blue variable phase. It is …

Aims. Every 5.5 years, η Car's light curve and spectrum change remarkably across all
observed wavelength bands. These so-called spectroscopic events are most likely caused …

Determining accurate orbits of binary stars with powerful winds is challenging. The dense
outflows increase the effective photospheric radius, precluding direct observation of the …

FUV spectra of η Car, recorded across two decades with HST/STIS, document multiple
changes in resonant lines caused by dissipating extinction in our line of sight. The FUV flux …

We have used (i) Hubble Space Telescope Advanced Camera for Surveys imaging and
Space Telescope Imaging Spectrograph spectroscopy,(ii) ground-based Precision …

Eta Carinae, the closest, active, massive binary containing a highly unstable Luminous Blue
Variable, exhibits expanding, compressed wind shells, seen in emission, that are spatially …

We have monitored the massive binary star η Carinae with the CTIO/Small and Moderate
Aperture Research Telescope System 1.5 m telescope and CHIRON spectrograph from the …