Vigorous atmospheric motion in the red supergiant star Antares

Abstract

Red supergiant stars represent a late stage of the evolution of stars more massive than about nine solar masses, in which they develop complex, multi-component atmospheres. Bright spots have been detected in the atmosphere of red supergiants using interferometric imaging. Above the photosphere of a red supergiant, the molecular outer atmosphere extends up to about two stellar radii. Furthermore, the hot chromosphere (5,000 to 8,000 kelvin) and cool gas (less than 3,500 kelvin) of a red supergiant coexist at about three stellar radii. The dynamics of such complex atmospheres has been probed by ultraviolet and optical spectroscopy. The most direct approach, however, is to measure the velocity of gas at each position over the image of stars as in observations of the Sun. Here we report the mapping of the velocity field over the surface and atmosphere of the nearby red supergiant Antares. The two-dimensional velocity field map obtained from our near-infrared spectro-interferometric imaging reveals vigorous upwelling and downdrafting motions of several huge gas clumps at velocities ranging from about -20 to +20 kilometres per second in the atmosphere, which extends out to about 1.7 stellar radii. Convection alone cannot explain the observed turbulent motions and atmospheric extension, suggesting that an unidentified process is operating in the extended atmosphere.

27 pages, 8 figures, published in Nature

References in corpus (5)

• Interferometric data reduction with AMBER/VLTI.Principle,estimators and illustration
• Atmospheric dynamics and the mass loss process in red supergiant stars
• What causes the large extensions of red-supergiant atmospheres? Comparisons of interferometric observations with 1-D hydrostatic, 3-D convection, and 1-D pulsating model atmospheres
• Properties of the CO and H${}_2$O MOLsphere of the red supergiant Betelgeuse from VLTI/AMBER observations
• CHARA/MIRC observations of two M supergiants in Perseus OB1: temperature, Bayesian modeling, and compressed sensing imaging

Cited by in corpus (18)

• The close circumstellar environment of Betelgeuse - V. Rotation velocity and molecular envelope properties from ALMA
• Analytic, dust-independent mass-loss rates for red supergiant winds initiated by turbulent pressure
• An extensive grid of DARWIN models for M-type AGB stars I. Mass-loss rates and other properties of dust-driven winds
• The evolution of DARWIN: current status of wind models for AGB stars
• Tomography of cool giant and supergiant star atmospheres II. Signature of convection in the atmosphere of the red supergiant star $\mu$ Cep
• Establishing a mass-loss rate relation for red supergiants in the Large Magellanic Cloud
• Is Betelgeuse Really Rotating? Synthetic ALMA Observations of Large-scale Convection in 3D Simulations of Red Supergiants
• ALMA and VLA reveal the lukewarm chromospheres of the nearby red supergiants Antares and Betelgeuse
• The VLT/SPHERE view of the ATOMIUM cool evolved star sample. I. Overview: Sample characterization through polarization analysis
• The inner circumstellar dust of the red supergiant Antares as seen with VLT/SPHERE/ZIMPOL
• Optical interferometry and Gaia measurement uncertainties reveal the physics of asymptotic giant branch stars
• Investigating the metallicity dependence of the mass-loss rate relation of red supergiants
• Why Chromatic Imaging Matters
• MAGIS (Measuring Abundances of red super Giants with Infrared Spectroscopy) project I. Establishment of an abundance analysis procedure for red supergiants and its evaluation with nearby stars
• MOLsphere and pulsations of the Galactic Center's red supergiant GCIRS 7 from VLTI/GRAVITY
• On the optical properties of Resonant Drag Instabilities: Variability of Asymptotic Giant Branch and R Coronae Borealis stars
• First images of Antares photosphere from spectropolarimetry
• Precision Analysis of Evolved Stars