Related papers: Eta Carinae across the 2003.5 minimum: Spectroscop…

We have monitored the massive binary star $\eta$ Carinae with the CTIO/SMARTS 1.5~m telescope and CHIRON spectrograph from the previous apastron passage of the system through the recent 2014.6 periastron passage. Our monitoring has resulted…

$\eta$ Carinae is an extremely luminous and energetic colliding-wind binary. The combination of its orbit and orientation, with respect to our line of sight, enables direct investigation of the conditions and geometry of the colliding…

The highly eccentric binary system Eta Carinae shows numerous time-variable emission and absorption features. These observational signatures are the result of interactions between the complex three-dimensional (3D) wind-wind collision…

In order to study the distribution of gas and ionizing radiation around eta Car and their implications for its likely companion star, we have examined high-excitation emission lines of [Ne III], [Fe III], etc., in spectra obtained with the…

We report new HST/STIS observations that map the high-ionization forbidden line emission in the inner arcsecond of Eta Car, the first that fully image the extended wind-wind interaction region of the massive colliding wind binary. These…

We report near-IR spectroscopic observations of the Eta Carinae massive binary system during 2008-2009 using VLT/CRIRES. We detect a strong, broad absorption wing in He I 10833 extending up to -1900 km/s across the 2009.0 spectroscopic…

The Homunculus reflection nebula around eta Carinae provides a rare opportunity to observe the spectrum of a star from multiple latitudes. We present STIS spectra of several positions in the Homunculus, showing directly that eta Car has an…

Aims. Every 5.5 years eta Car's light curve and spectrum change remarkably across all observed wavelength bands. We compare the recent spectroscopic event in mid-2014 to the events in 2003 and 2009 and investigate long-term trends. Methods.…

We report the detection of the emission line He II 4686 A in eta Carinae. The equivalent width of this line is ~100 mA along most of the 5.5-yr cycle and jumps to ~900 mA just before phase 1.0, followed by a brief disappearance. The…

The massive binary system Eta Carinae and the surrounding HII complex, the Carina Nebula, are potential particle acceleration sites from which very-high-energy (VHE; E > 100 GeV) \gamma-ray emission could be expected. This paper presents…

We propose an explanation to the puzzling appearance of a wide blue absorption wing in the He I 10830A P-Cygni profile of the massive binary star Eta Carinae several months before periastron passage. Our basic assumption is that the…

We report on H-alpha spectroscopy of the 2009.0 spectroscopic event of eta Carinae collected via SMARTS observations using the CTIO 1.5 m telescope and echelle spectrograph. Our observations were made almost every night over a two month…

{\eta} Carinae is an extremely massive binary system in which rapid spectrum variations occur near periastron. Most notably, near periastron the He II $\lambda 4686$ line increases rapidly in strength, drops to a minimum value, then…

The 6307A emission line in the spectrum of Eta Car (Martin et al. 2006) is blue-shifted [S III] 6313A emission originating from the outer wind structures of the massive binary system. We realized the identification while analyzing multiple…

FUV spectra of Eta 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 has increased nearly ten-fold which has led to increased…

The {\eta} Carinae binary system hosts the most massive stars with the highest known mass-loss rate. Its dense wind encounters the faster wind expelled by the companion, dissipating mechanical energy in the shock, accelerating particles up…

Stellar wind-emission features in the spectrum of eta Carinae have decreased by factors of 1.5-3 relative to the continuum within the last 10 years. We investigate a large data set from several instruments (STIS, GMOS, UVES) obtained…

Using the high dispersion NUV mode of the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST) to observe Eta Carinae, we have resolved and identified over 500 sharp, circumstellar absorption lines of…

Eta Carinae ($\eta$\,Car) exhibits a unique set of P Cygni profiles with both broad and narrow components. Over many decades, the spectrum has changed -- there has been an increase in observed continuum fluxes and a decrease in FeII and HI…

Eta Car is one of the most intriguing luminous blue variables in the Galaxy. Observations and models at different wavelengths suggest a central binary with a 5.54 yr period residing in its core. 2D and 3D radiative transfer and hydrodynamic…