Seismic constraints on rotation of Sun-like star and mass of exoplanet.

Constraints on stellar rotation and planet mass. The dark-red and light-red regions are the 1-σ and 2- σ seismic constraints on stellar rotation in the plane (Ω / ΩSun) - (sin i), where Ω is the bulk angular velocity, ΩSun / 2 π= 0.424 μHz is the solar Ca
Constraints on stellar rotation and planet mass. The dark-red and light-red regions are the 1-σ and 2- σ seismic constraints on stellar rotation in the plane (Ω / ΩSun) - (sin i), where Ω is the bulk angular velocity, ΩSun / 2 π= 0.424 μHz is the solar Ca
Advertised on
References
Proceedings of the National Academy of Sciences, vol. 110, issue 33, pp. 13267-13271

Rotation is thought to drive cyclic magnetic activity in the Sun and Sun-like stars. Stellar dynamos, however, are poorly understood owing to the scarcity of observations of rotation and magnetic fields in stars. Here, inferences are drawn on the internal rotation of a distant Sun-like star by studying its global modes of oscillation. We report asteroseismic constraints imposed on the rotation rate and the inclination of the spin axis of the Sun-like star HD52265, a CoRoT prime target known to host a planetary companion. These seismic inferences are remarkably consistent with an independent spectroscopic observation (rotational line broadening) and with the observed rotation period of starspots. Further, asteroseismology constrains the mass of exoplanet HD52265b. Under the standard assumption that the stellar spin axis and the axis of the planetary orbit coincide, the minimum spectroscopic mass of the planet can be converted into a true mass of 1.85 +0.52- 0.42MJupiter which implies that it is a planet, not a brown dwarf.

News type
Research news

It may interest you

  • MaNGA galaxies
    Research news
    Constraints on the in situ and ex situ stellar masses in nearby galaxies obtained with artificial intelligence
    The hierarchical model of galaxy evolution suggests that mergers have a substantial impact on the intricate processes that drive stellar assembly within a galaxy. However, accurately measuring the contribution of accretion to a galaxy's total stellar mass and its balance with in situ star formation poses a persistent challenge, as it is neither directly observable nor easily inferred from observational properties. Using data from MaNGA, we present theory-motivated predictions for the fraction of stellar mass originating from mergers in a statistically significant sample of nearby galaxies
    Advertised on
  • Research news
    Scientific results with the QUIJOTE-MFI wide survey: The anomalous microwave emission in our Galaxy and M31
    In the 90s, the COBE satellite discovered that not all the microwave emission from our Galaxy behaved as expected. Part of this signal was later assigned to a fresh new emission component, spatially correlated with the Galactic dust emission, which showed greater importance in the microwave range of frequencies. It has been named since as “anomalous microwave emission”, or AME. The current main hypothesis to explain the AME origin is that it is emitted by small dust particles which undergo fast spinning movements. In Fernández-Torreiro et al. (2023), we study the observational properties of
    Advertised on
  • Action space (normalized to the sum of the three actions of motion, Jtot) of Gaia RVS stars
    Research news
    The Metal-Poor Edge of the Milky Way’s Thin Disk
    The formation and evolution of the disk of our Galaxy, the Milky Way, remains an enigma in astronomy. In particular, the relationship between the thick disk and the thin disk —two key components of the Milky Way— is still unclear. Understanding the chemical and dynamical properties of the stars within these disks is crucial, especially in the parameter spaces where their characteristics overlap, such the metallicity regime around [Fe/H] ~ -0.7, which marks the metal-poor end of the thin disk, higher than that of the thick disk. This is often interpreted as an indication that the thin disk
    Advertised on