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 …

We have analyzed high spatial, moderate spectral resolution observations of η Carinae (η
Car) obtained with the STIS from 1998.0 to 2004.3. The data were obtained at discrete times …

The binary η Carinae is the closest example of a very massive star, which may have formed
through a merger during its Great Eruption in the mid-19th century. We aimed to confirm and …

The periodic spectroscopic events in η Carinae are now well established and occur near the
periastron passage of two massive stars in a very eccentric orbit. Several mechanisms have …

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 …

We report the detection of the emission line He II λ4686 in η Carinae. The equivalent width
of this line is~ 100 mÅ along most of the 5.5 yr cycle and jumps to~ 900 mÅ just before …

Eta Carinae's spectroscopic events (periastron passages) in 2003, 2009, and 2014 differed
progressively. He ii λ4687 and nearby N ii multiplet 5 have special significance because …

Context. The periodicity of 5.5 years for some observational events occurring in η Carinae
manifests itself across a large wavelength range and has been associated with its binary …

We describe and analyze Hubble Space Telescope (HST) observations of transient
emission near 4680 Å in η Car, reported earlier by Steiner & Damineli. If, as seems …

A full description of the 5.5-yr low excitation events in η Carinae is presented. We show that
they are not as simple and brief as previously thought, but a combination of two components …