Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Curious Case of the North Star: the continuing tension between
  evolution models and measurements of Polaris   Polaris is the nearest Cepheid to us and as such holds a special place in our
understanding of Cepheids in general and the Leavitt Law. In the past couple of
decades, we have learned many new things about the star as a Cepheid and as the
primary component of a multiple star system. As such, we are more precisely
measuring the mass, radius and evolution of Polaris. However, as we learn more,
it is becoming clear that we understand less. There is evidence that Polaris is
much less massive than stellar evolution models suggest and that Polaris is a
much younger star than its main sequence companion. In this work, we review
some of the recent measurements and their connections with past studies. We
then present new stellar evolution models and populations synthesis
calculations to compare with the new mass measurements by Evans et al. (2018).
We find that the mass discrepancy for Polaris is about 50\%. We also find that
there is a likely age discrepancy between Polaris and its companion, but that
there is also a very small probability that the discrepancy is not real.

15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn