Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The connection between missing AGB stars and extended horizontal
  branches   Recent surveys confirm early results about a deficiency or even absence of
CN-strong stars on the asymptotic giant branch (AGB) of globular clusters
(GCs), although with quite large cluster-to-cluster variations. In general,
this is at odds with the distribution of CN band strengths among first ascent
red giant branch (RGB) stars. Norris et al. proposed that the lack of CN-strong
stars in some clusters is a consequence of a smaller mass of these stars that
cannot evolve through the full AGB phase. In this short paper we found that the
relative frequency of AGB stars can change by a factor of two between different
clusters. We also find a very good correlation between the minimum mass of
stars along the horizontal branch (Gratton et al. 2010) and the relative
frequency of AGB stars, with a further dependence on metallicity. We conclude
that indeed the stars with the smallest mass on the HB cannot evolve through
the full AGB phase, being AGB-manque'. These stars likely had large He and N
content, and large O-depletion. We then argue that there should not be AGB
stars with extreme O depletion, and few of them with a moderate one.

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The categories of this paper are: hep-ph
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The categories of this paper are: physics
14
The categories of this paper are: math-ph
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The categories of this paper are: eess
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The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
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The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
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The categories of this paper are: supr-con