Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cepheid investigations in the era of space photometric missions   Cepheid stars are crucial objects for a variety of topics that range from
stellar pulsation and the evolution of intermediate-mass stars to the
understanding the structure of the Galaxy and the Universe through the distance
measurements they provide. The developments in hydrodynamical calculations, the
release of large ground-based surveys, and the advent of continuous,
space-based photometry revealed many puzzling phenomena about these stars in
the last few years. In this paper I collected some important and new results in
the topics of distance measurements and binarity investigations. I also
summarize the most recent discoveries in their light variations, such as period
doubling, modulation, low-amplitude additional modes, period jitter and the
signs of granulation, and discuss the new opportunities that current and future
space missions will offer for us.

4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph