Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Characterization of the variability in the O+B eclipsing binary HD
  165246   O-stars are known to experience a wide range of variability mechanisms
originating at both their surface and their near-core regions. Characterization
and understanding of this variability and its potential causes are integral for
evolutionary calculations. We use a new extensive high-resolution spectroscopic
data set to characterize the variability observed in both the spectroscopic and
space-based photometric observations of the O+B eclipsing binary HD~165246. We
present an updated atmospheric and binary solution for the primary component,
involving a high level of microturbulence ($13_{-1.3}^{+1.0}\,$km\,s$^{-1}$)
and a mass of $M_1=23.7_{-1.4}^{+1.1}$~M$_{\odot}$, placing it in a sparsely
explored region of the Hertzsprung-Russell diagram. Furthermore, we deduce a
rotational frequency of $0.690\pm 0.003\,$d$^{-1}$ from the combined
photometric and line-profile variability, implying that the primary rotates at
40\% of its critical Keplerian rotation rate. We discuss the potential
explanations for the overall variability observed in this massive binary, and
discuss its evolutionary context.

24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom