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Title: On the age of Gliese 86

Gliese 86 is a nearby planet hosting a visual binary consisting of a K-type primary, Gl 86 A, and a white dwarf secondary, Gl 86 B. In this work, we present a model atmosphere analysis of the M {sub A} = 0.83 M {sub ☉} primary, whose chemistry unambiguously identifies it as a 10 Gyr old disk star. For the secondary, this gives rise to a progenitor mass M {sub prog} = 1.11 ± 0.05 M {sub ☉}, and—by inference with its local sibling o {sup 2} Eri—a white dwarf mass M {sub B} = 0.49 ± 0.02 M {sub ☉}. The discrepancy with the 2-3 Gyr chromospheric age of Gl 86 A, as first noted by Rocha-Pinto, Castilho and Maciel, is thus most plausibly the result of a former accretion of mass and angular momentum from the distant degenerate. In consequence, this also implies that with respect to shorter-period systems, like Sirius or Procyon, one must expect significant wind accretion when they evolve through the planetary nebula phase, such that the system ages cannot be reliably determined from their currently bright primaries.
Authors:
; ; ;  [1]
  1. Astronomisches Institut, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum (Germany)
Publication Date:
OSTI Identifier:
22357151
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 785; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANGULAR MOMENTUM; ATMOSPHERES; BINARY STARS; MASS TRANSFER; PLANETARY NEBULAE; PLANETS; STELLAR WINDS; WHITE DWARF STARS