Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: CK Aqr time keeping. Evidence for a third body   Photometric measurements of the contact binary system CK Aqr are presented.
49 new times of minimum were obtained between 2005 and 2020. Along with already
published observations, this allows the derivation of an improved ephemeris.
The resulting O-C diagram shows oscillations which are interpreted as the light
time travel effect due to a third component, with a period of 8.2 years.

16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics