Direct measurement of the size and shape of the present-day stellar wind of $\eta$ Carinae

  title={Direct measurement of the size and shape of the present-day stellar wind of \$\eta\$ Carinae},
  author={Roy van Boekel and Pierre Kervella and Markus Schoeller and Tom M. Herbst and Wolfgang Brandner and L. B. F. M. Waters and D. John Hillier and Francesco Paresce and Rainer Lenzen and Anne-Marie Lagrange},
  journal={Astronomy and Astrophysics},
We present new high angular resolution observations at near-IR wavelengths of the core of the Luminous Blue Variable Carinae, using NAOS-CONICA at the VLT and VINCI at the VLT Interferometer (VLTI). The latter observations provide spatial information on a scale of 5 milli-arcsec or 11 AU at the distance of Carinae. The present-day stellar wind of Carinae is resolved on a scale of several stellar radii. Assuming spherical symmetry, we find a mass loss rate of 1:610 3 M/yr and a wind clumping… 

Figures from this paper

Eta Car through the Eyes of Interferometers

The core of the nebula surrounding Eta Carinae has recently been observed with VLT/NACO, VLTI/VINCI, VLTI/MIDI and VLTI/AMBER in order to spatially and spectrally constrain the warm dusty environment

The polar wind of the fast rotating Be star Achernar. VINCI/VLTI interferometric observations of an

Be stars show evidence of mass loss and circumstellar envelopes (CSE), from UV resonance lines, near-IR excesses and the presence of episodic hydrogen emission lines. The geometry of these envelopes

Resolving the Hα-emitting Region in the Wind of η Carinae

The massive evolved star η Carinae is the most luminous star in the Milky Way and has the highest steady wind mass-loss rate of any known star. Radiative transfer models of the spectrum by Hillier et


We analyze interferometric measurements of the luminous blue variable Eta Carinae with the goal of constraining the rotational velocity of the primary star and probing the influence of the companion.

The sub-arcsecond dusty environment of Eta Carinae

The core of the nebula surrounding Eta Carinae has been observed with the VLT Adaptive Optics system NACO and with the interferometer VLTI/MIDI to constrain spatially and spectrally the warm dusty

The VLT-FLAMES survey of massive stars: mass loss and rotation of early-type stars in the SMC

We have studied the optical spectra of a sample of 31 O- and early B-type stars in the Small Magellanic Cloud, 21 of which are associated with the young massive cluster NGC 346. Stellar parameters

Interferometric observations of η Carinae with VINCI/VLTI

Context. The bright starCarinae is the most massive and luminous star in our region of the Milky Way. Though it has been extensively studied using many different techniques, its physical nature and

The empirical metallicity dependence of the mass-loss rate of O- and early B-type stars

We present a comprehensive study of the observational dependence of the mass-loss rate in stationary stellar winds of hot massive stars on the metal content of their atmospheres. The metal content of

Maximum mass-loss rates of line-driven winds of massive stars: The effect of rotation and an application to eta Carinae

We investigate the effect of rotation on the maximum mass-loss rate due to an optically-thin radiatively-driven wind according to a formalism which takes into account the possible presence of any

Near-Infrared Evidence for a Sudden Temperature Increase in Eta Carinae

Aims. Eta Car's ultra-violet, optical, and X-ray light curves and its spectrum suggest a physical change in its stellar wind over the last decade. It was proposed that the mass-loss rate decreased by



The shape of eta Carinae and LBV nebulae

Stellar winds emitted by rotating massive stars may show two main components: rstly bipolar lobes with low density and fast wind, produced by the higher Te and gravity at the poles (\ge{eect");

Discovery of a massive equatorial torus in the η Carinae stellar system

The enigmatic object η Carinae is believed to represent an important, but short-lived, unstable phase in the life of the most massive stars, occurring shortly before they explode as supernovae or

Mass and Kinetic Energy of the Homunculus Nebula around η Carinae

We examine thermal infrared images of η Car at wavelengths from 4.8 to 25 μm obtained with the MIRAC3 camera system at the Magellan Observatory, and we conclude that η Car's circumstellar Homunculus

Radiatively Driven Winds and the Shaping of Bipolar Luminous Blue Variable Nebulae

Nebulae around luminous blue variable (LBV) stars are often characterized by a bipolar, prolate form. In the standard interpretation of the generalized interacting stellar winds model, this bipolar

On the Nature of the Central Source in η Carinae

Long-slit spectroscopic observations of η Carinae and its Homunculus have recently been obtained using STIS on the Hubble Space Telescope (HST). We have extracted the spectrum of the central source

The Shape and Orientation of the Homunculus Nebula Based on Spectroscopic Velocities

Doppler velocities give information about the three-dimensional shape and orientation of the bipolar ejecta of η Car. We report slit spectroscopy obtained using the Space Telescope Imaging

Recent Changes in the Near-Infrared Structure of η Carinae

Near-infrared imaging at two phases in the 5 yr spectroscopic cycle of η Carinae reveals changes in the spatial structure of the inner core that may be related to recently reported near-infrared

Inhibition of Wind-Compressed Disk Formation by Nonradial Line Forces in Rotating Hot-Star Winds

We investigate the effects of nonradial line forces on the formation of a “wind-compressed disk” (WCD) around a rapidly rotating B star. Such nonradial forces can arise both from asymmetries in the

The homunculus of Eta Carinae: An interacting stellar winds paradigm

We simulate the origin and evolution of the bipolar nebula surrounding Eta Car using numerical two-dimensional gasdynamic models. The generalized interacting stellar winds scenario, wherein a stellar

CONICA: the high-resolution near-infrared camera for the ESO VLT

A high resolution near IR camera (CONICA) for the firs VLT unit is under development, which will provide diffraction limited spatial resolution being combined with the adaptive optics system NAOS.