On the origin of stars with and without planets. Tc trends and clues to Galactic evolution.

Tc slopes versus ages for the full sample (top panel) and for the solar analogs (bottom panel). Gray solid lines provide linear fits to the data points.
Tc slopes versus ages for the full sample (top panel) and for the solar analogs (bottom panel). Gray solid lines provide linear fits to the data points.
Advertised on
References
Adibekyan et al. 2014 A&A letters, 564, L15

We explore a sample of 148 solar-like stars to search for a possible correlation between the slopes of the abundance trends versus condensation temperature (known as the Tc slope) with stellar parameters and Galactic orbital parameters in order to understand the nature of the peculiar chemical signatures of these stars and the possible connection with planet formation. We find that the Tc slope significantly correlates (at more than 4σ) with the stellar age and the stellar surface gravity (see Figure 1). We also find tentative evidence that the Tc slope correlates with the mean galactocentric distance of the stars (Rmean), suggesting that those stars that originated in the inner Galaxy have fewer refractory elements relative to the volatiles. While the average Tc slope for planet-hosting solar analogs is steeper than that of their counterparts without planets, this difference probably reflects the difference in their age and Rmean. We conclude that the age and probably the Galactic birth place are determinant to establish the star’s chemical properties. Old stars (and stars with inner disk origin) have a lower refractory-to-volatile ratio.

News type
Research news

It may interest you

  • log_n_c_n_o_bsgs_ann_groups7
    Research news
    The origin of the brightest stars in any Galaxy lies in stellar mergers
    Massive stars, those over ten times heavier than our Sun, are the conduits of most elements of the periodic table and drive the morphological and chemical makeup of their host galaxies. Yet the origin of the most luminous and hottest stars among them, called 'blue supergiants', has been debated for many decades. Blue supergiants are strange stars. First, they are observed in large numbers, despite conventional stellar physics expecting them to live only briefly. Second, they are typically found alone, despite most massive stars being born with companions. Third, the majority of them harbour
    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
  • alpha_plot_density_gamma_b
    Research news
    The universal variability of the stellar initial mass function probed by the TIMER survey
    The universality of the stellar initial mass function (IMF) is one of the most widespread assumptions in modern Astronomy and yet, it might be flawed. While observations in the Milky Way generally support an IMF that is invariant with respect to the local conditions under which stars form, measurements of massive early-type galaxies systematically point towards a non-universal IMF. To bridge the gap between both sets of evidence, in this work we measured for the first time the low-mass end of the IMF from the integrated spectra of a Milky Way-like galaxy, NGC3351. We found that the slope of
    Advertised on