Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Amplitude Modulation of Cepheid Radial Velocity Curves as a Systematic
  Source of Uncertainty for Baade-Wesselink Distances   I report on the recent discovery of modulation in the radial velocity curves
in four classical Cepheids. This discovery may enable significant improvements
in the accuracy of Baade-Wesselink distances by revealing a not previously
considered systematic source of uncertainty.

20
The categories of this paper are: acc-phys
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The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
10
The categories of this paper are: q-bio