Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonradial and radial period changes in the Delta Scuti star 4 CVn I.
  700+ nights of photometry   The nature of period and amplitude changes in nonradial pulsators is
presently unknown. It is therefore important to examine the correlations
between these changes in stars with a large number of simultaneously excited
pulsation modes. However, the small amplitudes require extensive high-precision
photometry covering many years. We present 702 nights of high-precision
photometry of the evolved Delta Scuti variable 4 CVn obtained from 2005 - 2012
with a dedicated telescope. We detected 64 frequencies, of which 38 can be
identified as combinations and harmonics. The relative amplitudes of the
combination frequencies are similar to those found in 44 Tau and show no
evidence for resonant mode coupling. Significant period and amplitude changes
are detected for the dominant modes. The known prograde and retrograde modes
show period changes with opposite signs, while the radial mode exhibits only
small, cyclical period changes. For each mode, the period changes are constant
over the eight years and range from (1/P)dP/dt = -16 to +13 parts per million.
On the other hand, the amplitude variations show no systematic behavior between
different pulsation modes. The behavior of the prograde, axisymmetric, and
retrograde modes indicates a constant decrease in the rotational splitting over
the eight years.

31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc