# The radii and limb darkenings of α Centauri A and B . Interferometric measurements with VLTI/PIONIER

@article{Kervella2016TheRA,
title={The radii and limb darkenings of $\alpha$ Centauri A and B . Interferometric measurements with VLTI/PIONIER},
author={Pierre Kervella and Lionel Bigot and Alexandre Gallenne and Fr'ed'eric Th'evenin},
journal={Astronomy and Astrophysics},
year={2016},
volume={597}
}
• Published 19 October 2016
• Physics
• Astronomy and Astrophysics
The photospheric radius is one of the fundamental parameters governing the radiative equilibrium of a star. We report new observations of the nearest solar-type stars α  Centauri A (G2V) and B (K1V) with the VLTI/PIONIER optical interferometer. The combination of four configurations of the VLTI enable us to measure simultaneously the limb darkened angular diameter θ LD and the limb darkening parameters of the two solar-type stars in the near-infrared H band ( λ = 1.65 μ m). We obtain…

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## References

SHOWING 1-10 OF 75 REFERENCES

### The limb darkening of $\mathsf{\alpha}$ Centauri B - Matching 3D hydrodynamical models with interferometric measurements

• Physics, Geology
• 2006
For the nearby dwarf star α  Cen B (K1 V), we present limb-darkening predictions from a 3D hydrodynamical radiative transfer model of its atmosphere. We first compared the results of this model to a

### The diameter of the CoRoT target HD 49933 - Combining the 3D limb darkening, asteroseismology, and interferometry

• Physics, Geology
• 2011
Context. The interpretation of stellar pulsations in terms of internal structure depends on the knowledge of the fundamental stellar parameters. Long-base interferometers permit us to determine very

### Interferometric radius and limb darkening of the asteroseismic red giant η Serpentis with the CHARA Array

• Physics
• 2010
Context. The radius of a star is a very important constraint to evolutionary models, particularly when combined with asteroseismology. Diameters can now be measured interferometrically with great

### The diameters of $\alpha$ Centauri A and B - A comparison of the asteroseismic and VINCI/VLTI views

• Physics
• 2003
We compare the first direct angular diameter measurements obtained on our closest stellar neighbour, Centauri, to recent model diameters constrained by asteroseismic observations. Using the VINCI

### The angular sizes of dwarf stars and subgiants (Research Note) Non-linear surface brightness relations in BVRcIc from interferometry

• Physics
• 2008
Context. The prediction of stellar angular diameters from broadband photometry plays an important role in different applications. In particular, long-baseline interferometry, gravitational

### Gravity and limb-darkening coefficients for the Kepler, CoRoT, Spitzer, uvby, UBVRIJHK, and Sloan photometric systems

• Physics, Geology
• 2011
Aims. The complex physics of close binary stars is made even more challenging by the proximity effects that affect it. Understanding the influence of these proximity effects is one of the most

### New limb-darkening coefficients for Phoenix/1d model atmospheres - II. Calculations for 5000 K ≤ Teff ≤ 10 000 K Kepler, CoRot, Spitzer, uvby, UBVRIJHK, Sloan, and 2MASS photometric systems

• Physics
• 2012
Aims. The knowledge of how the specific intensity is distributed over the stellar disk is crucial for interpreting the light curves of extrasolar transiting planets, double-lined eclipsing binaries,

### ALMA observations of α Centauri - First detection of main-sequence stars at 3 mm wavelength

• Physics
• 2015
Context. The precise mechanisms that provide the non-radiative energy for heating the chromosphere and the corona of the Sun and those of other stars constitute an active field of research. By

### THE FAR-ULTRAVIOLET UPS AND DOWNS OF ALPHA CENTAURI

Four years (2010–2014) of semiannual pointings by the Hubble Space Telescope Imaging Spectrograph (STIS) on nearby Alpha Centauri have yielded a detailed time history of far-ultraviolet (FUV:

### THE UPS AND DOWNS OF α CENTAURI

The following is a progress report on the long-term coronal (T ∼ 1 MK) activity of α Centauri A (HD 128620: G2 V) and B (HD 128621: K1 V). Since 2005, Chandra X-Ray Observatory has carried out