Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exoplanets or Dynamic Atmospheres? The Radial Velocity and Line Shape
  Variations of 51 Pegasi and Tau Bootis   Because of our relatively low spectral resolution, we compare our
observations with Gray's line bisector data by fitting observed line profiles
to an expansion in terms of orthogonal (Hermite) functions. To obtain an
accurate comparison, we model the emergent line profiles from rotating and
pulsating stars, taking the instrumental point spread function into account. We
describe this modeling process in detail.
  We find no evidence for line profile or strength variations at the radial
velocity period in either 51 Peg or in Tau Boo. For 51 Peg, our upper limit for
line shape variations with 4.23-day periodicity is small enough to exclude with
10 sigma confidence the bisector curvature signal reported by Gray & Hatzes;
the bisector span and relative line depth signals reported by Gray (1997) are
also not seen, but in this case with marginal (2 sigma) confidence. We cannot,
however, exclude pulsations as the source of 51 Peg's radial velocity
variation, because our models imply that line shape variations associated with
pulsations should be much smaller than those computed by Gray & Hatzes; these
smaller signals are below the detection limits both for Gray & Hatzes' data and
for our own.
  Tau Boo's large radial velocity amplitude and v*sin(i) make it easier to test
for pulsations in this star. Again we find no evidence for periodic line-shape
changes, at a level that rules out pulsations as the source of the radial
velocity variability. We conclude that the planet hypothesis remains the most
likely explanation for the existing data.

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The categories of this paper are: hep-ph
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The categories of this paper are: econ
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The categories of this paper are: patt-sol
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The categories of this paper are: q-fin
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The categories of this paper are: alg-geom
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The categories of this paper are: q-bio
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The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: math-ph
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The categories of this paper are: math
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: adap-org