The metallicity signature of evolved stars with planets

被引：0

作者：

机构：

[1] Maldonado, J.

[2] Villaver, E.

[3] Eiroa, C.

来源：

| 1600年 / EDP Sciences卷 / 554期

关键词：

Context; Currently; the core accretion model has its strongest observational evidence on the chemical signature of mostly main sequence stars with planets. Aims.We aim to test whether the well-established correlation between the metallicity of the star and the presence of giant planets found for main sequence stars still holds for the evolved and generally more massive giant and subgiant stars. Although several attempts have been made so far; the results are not conclusive since they are based on small or inhomogeneous samples. Methods.We determine in a homogeneous way the metallicity and individual abundances of a large sample of evolved stars; with and without known planetary companions; and discuss their metallicity distribution and trends. Our methodology is based on the analysis of high-resolution échelle spectra (R ≥ 67 000) from 2-3 m class telescopes. It includes the calculation of the fundamental stellar parameters (Teff; logg; microturbulent velocity; and metallicity) by applying iron ionisation and excitation equilibrium conditions to several isolated Fe i and Fe ii lines; as well as; calculating individual abundances of different elements such as Na; Mg; Si; Ca; Ti; Cr; Co; or Ni. Results.The metallicity distributions show that giant stars hosting planets are not preferentially metal-rich because they have similar abundance patterns to giant stars without known planetary companions. We have found; however; a very strong relation between the metallicity distribution and the stellar mass within this sample. We show that while the less massive giant stars with planets (M* ≥ 1.5 M·) are not metal rich; the metallicity of the sample of massive (M* 1.5 M·); young (age * ≥ 1.5 M· show similar abundance patterns. However; planet and non-planet hosts with masses M* 1.5 M· show differences in the abundances of some elements; specially Na; and Ni. In addition; we find the sample of subgiant stars with planets to be metal rich; showing similar metallicities to main-sequence planet hosts. Conclusions. While the metallicity distribution of planet-hosting subgiant stars and giant stars with stellar masses M* 1.5 M· fits well in the predictions of current core-accretion models; the fact that giant planet hosts in the mass domain M* ≥ 1.5 M· do not show metal enrichment is difficult to explain. Given that these stars have similar stellar parameters to subgiants and main-sequence planet hosts; the lack of the metal-rich signature in low-mass giants could be explained by a pollution scenario in the main sequence that gets erased as the star becomes fully convective. However; there is no physical reason why it should play a role for giants with masses M* ≥ 1.5 M· yet not be observed for giants with M * > 1.5 M·. © 2013 ESO;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

Journal article (JA)

引用

共 50 条

[21] Spitzer spectra of evolved stars in ω Centauri and their low-metallicity dust production
McDonald, I.
van Loon, J. Th.
Sloan, G. C.
Dupree, A. K.
Zijlstra, A. A.
Boyer, M. L.
Gehrz, R. D.
Evans, A.
Woodward, C. E.
Johnson, C. I.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2011, 417 (01) : 20 - 31
[22] Evolved massive stars at low metallicity: II. Red supergiant stars in the Small Magellanic Cloud
Yang, Ming
Bonanos, Alceste Z.
Jiang, Bi-Wei
Gao, Jian
Gavras, Panagiotis
Maravelias, Grigoris
Wang, Shu
Chen, Xiao-Dian
Tramper, Frank
Ren, Yi
Spetsieri, Zoi T.
Xue, Meng-Yao
ASTRONOMY & ASTROPHYSICS, 2020, 639
[23] On the possible correlation between the orbital periods of extrasolar planets and the metallicity of the host stars
Sozzetti, A
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2004, 354 (04) : 1194 - 1200
[24] The PennState/Torun Center for Astronomy Search for Planets around Evolved Stars.
Niedzielski, Andrzej
Wolszczan, Aleksander
EXTREME SOLAR SYSTEMS, 2008, 398 : 71 - 74
[25] Four new planets around giant stars and the mass-metallicity correlation of planet-hosting stars
Jones, M. I.
Jenkins, J. S.
Brahm, R.
Wittenmyer, R. A.
Olivares E., F.
Melo, C. H. F.
Rojo, P.
Jordan, A.
Drass, H.
Butler, R. P.
Wang, L.
ASTRONOMY & ASTROPHYSICS, 2016, 590
[26] A correlation between the heavy element content of transiting extrasolar planets and the metallicity of their parent stars
Guillot, T
Santos, NC
Pont, F
Iro, N
Melo, C
Ribas, I
ASTRONOMY & ASTROPHYSICS, 2006, 453 (02) : L21 - L24
[27] EFFECT OF THE ROTATION, TIDAL DISSIPATION HISTORY AND METALLICITY OF STARS ON THE EVOLUTION OF CLOSE-IN PLANETS
Bolmont, E.
Gallet, F.
Mathis, S.
Charbonnel, C.
Amard, L.
ASTRO FLUID 2016, 2019, 82 : 71 - 79
[28] Do Close-in Giant Planets Orbiting Evolved Stars Prefer Eccentric Orbits?
Grunblatt, Samuel K.
Huber, Daniel
Gaidos, Eric
Lopez, Eric D.
Barclay, Thomas
Chontos, Ashley
Sinukoff, Evan
Van Eylen, Vincent
Howard, Andrew W.
Isaacson, Howard T.
ASTROPHYSICAL JOURNAL LETTERS, 2018, 861 (01)
[29] Metallicity, debris discs and planets
Greaves, JS
Fischer, DA
Wyatt, MC
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2006, 366 (01) : 283 - 286
[30] A metallicity recipe for rocky planets
Dawson, Rebekah I.
Chiang, Eugene
Lee, Eve J.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2015, 453 (02) : 1471 - 1483

← 1 2 3 4 5 →