Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Helium settling in F stars: constraining turbulent mixing using observed
  helium glitch signature   Recent developments in asteroseismology -- thanks to space-based missions
such as {\it CoRoT} and {\it Kepler} -- provide handles on those properties of
stars that were either completely inaccessible in the past or only poorly
measured. Among several such properties is the surface helium abundance of F
and G stars. We used the oscillatory signature introduced by the ionization of
helium in the observed oscillation frequencies to constrain the amount of
helium settling in F stars. For this purpose, we identified three promising F
stars for which the standard models of atomic diffusion predict large settling
(or complete depletion) of surface helium. Assuming turbulence at the base of
envelope convection zone slows down settling of the helium and heavy elements,
we found an envelope mixed mass of approximately $5 \times 10^{-4}$M$_\odot$
necessary to reproduce the observed amplitude of helium signature for all the
three stars. This is much larger than the mixed mass of the order of
$10^{-6}$M$_\odot$ found in the previous studies performed using the
measurements of the heavy element abundances. This demonstrates the potential
of using the helium signature together with measurements of the heavy element
abundances to identify the most important physical processes competing against
atomic diffusion, allowing eventually to correctly interpret the observed
surface abundances of hot stars, consistent use of atomic diffusion in
modelling both hot and cool stars, and shed some light on the long-standing
cosmological lithium problem.

11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph