Interferometric observations of eta Carinae with VINCI/VLTI

Abstract

Context: The bright star eta Carinae 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 mechanism that led to the creation of the Homunculus nebula are still debated. Aims: We aimed at resolving the central engine of the eta Carinae complex in the near-infrared on angular scales of a few milliarcseconds. Methods: We used the VINCI instrument of the VLTI to recombine coherently the light from two telescopes in the K band. Results: We report a total of 142 visibility measurements of eta Car, part of which were analyzed by Van Boekel et al. (2003). These observations were carried out on projected baselines ranging from 8 to 112 meters in length, using either two 0.35 m siderostats or two 8-meter Unit Telescopes. These observations cover the November 2001 - January 2004 period. Conclusions: The reported visibility data are in satisfactory agreement with the recent results obtained with AMBER/VLTI by Weigelt et al. (2006), asuming that the flux of eta Car encircled within 70 mas reaches 56% of the total flux within 1400 mas, in the K band. We also confirm that the squared visibility curve of eta Car as a function of spatial frequency follows closely an exponential model.

arXiv commentAccepted for publication in A&A as a Research note

References in corpus (10)

• The Structure of the Homunculus: I. Shape and Latitude Dependence from H2 and [Fe II] Velocity Maps of Eta Carinae
• Latitude-dependent effects in the stellar wind of Eta Carinae
• The diameters of Alpha Centauri A and B - A comparison of the asteroseismic and VINCI/VLTI views
• Near-Infrared interferometry of Eta Carinae with high spatial and spectral resolution using the VLTI and the AMBER instrument
• Direct measurement of the size and shape of the present-day stellar wind of Eta Carinae
• The UV Scattering Halo of the Central Source Associated with Eta Carinae
• Data reduction methods for single-mode optical interferometry - Application to the VLTI two-telescopes beam combiner VINCI
• The sub-arcsecond dusty environment of Eta Carinae
• Wide field interferometric imaging with single-mode fibers
• The Chrysalis Opens? Photometry from the Eta Carinae HST Treasury Project, 2002-2006

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• Observing and modeling the dynamic atmosphere of the low mass-loss C-star R Sculptoris at high angular resolution
• Is Eta Carinae a fast rotator, and how much does the companion influence the inner wind structure?
• Mid-infrared circumstellar emission of the long-period Cepheid l Carinae resolved with VLTI/MATISSE
• Grown-up stars physics with MATISSE