HIGH PRECISION ABUNDANCES OF THE OLD SOLAR TWIN HIP 102152: INSIGHTS ON Li DEPLETION FROM THE OLDEST SUN

Author(s):Show less -

Monroe, TalaWanda R. ^[1] ; Melendez, Jorge ^[1] ; Ramirez, Ivan ^[2] ; Yong, David ^[3] ; Bergemann, Maria ^[4] ; Asplund, Martin ^[3] ; Bedell, Megan ^[5] ; Maia, Marcelo Tucci ^[1] ; Bean, Jacob ^[5] ; Lind, Karin ^[6] ; Alves-Brito, Alan ^[3] ; Casagrande, Luca ^[3] ; Castro, Matthieu ^[7] ; do Nascimento, Jose-Dias ^[7] ; Bazot, Michael ^[8] ; Freitas, Fabricio C. ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Astron IAG USP, BR-05508900 Sao Paulo - Brazil

^[2] Univ Texas Austin, McDonald Observ, Austin, TX 78712 - USA

^[3] Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611 - Australia

^[4] Max Planck Inst Astrophys, D-85741 Garching - Germany

^[5] Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 - USA

^[6] Univ Cambridge, Inst Astron, Cambridge CB3 0HA - England

^[7] Univ Fed Rio Grande do Norte, Dept Fis Teor & Expt, BR-59072970 Natal, RN - Brazil

^[8] Univ Porto, Ctr Astrofis, P-4150762 Oporto - Portugal

• Document type: Journal article
• Source: Astrophysical Journal Letters; v. 774, n. 2 SEP 10 2013.
• Web of Science Citations: 37

Abstract

We present the first detailed chemical abundance analysis of the old 8.2 Gyr solar twin, HIP 102152. We derive differential abundances of 21 elements relative to the Sun with precisions as high as 0.004 dex (<= 1%), using ultra high-resolution (R = 110,000), high S/N UVES spectra obtained on the 8.2 m Very Large Telescope. Our determined metallicity of HIP 102152 is {[}Fe/H] = -0.013 +/- 0.004. The atmospheric parameters of the star were determined to be 54 K cooler than the Sun, 0.09 dex lower in surface gravity, and a microturbulence identical to our derived solar value. Elemental abundance ratios examined versus dust condensation temperature reveal a solar abundance pattern for this star, in contrast to most solar twins. The abundance pattern of HIP 102152 appears to be the most similar to solar of any known solar twin. Abundances of the younger, 2.9 Gyr solar twin, 18 Sco, were also determined from UVES spectra to serve as a comparison for HIP 102152. The solar chemical pattern of HIP 102152 makes it a potential candidate to host terrestrial planets, which is reinforced by the lack of giant planets in its terrestrial planet region. The following non-local thermodynamic equilibrium Li abundances were obtained for HIP 102152, 18 Sco, and the Sun: log epsilon (Li) = 0.48 +/- 0.07, 1.62 +/- 0.02, and 1.07 +/- 0.02, respectively. The Li abundance of HIP 102152 is the lowest reported to date for a solar twin, and allows us to consider an emerging, tightly constrained Li-age trend for solar twin stars. (AU)

• FAPESP's process: 12/24392-2 - High precision spectroscopy: impact in the study of planets, stars, the galaxy and cosmology
• Grantee: Jorge Luis Melendez Moreno
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 10/19810-4 - Probing planet formation with chemical abundances of solar type stars
• Grantee: TalaWanda Rose Monroe
• Support Opportunities: Scholarships in Brazil - Post-Doctoral