Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Discovery of Ellipsoidal Variations in the Kepler Light Curve of
  HAT-P-7   We present an analysis of the early Kepler observations of the previously
discovered transiting planet HAT-P-7b. The light curve shows the transit of the
star, the occultation of the planet, and the orbit phase-dependent light from
the planet. In addition, phase-dependent light from the star is present, known
as "ellipsoidal variations". The very nearby planet (only 4 stellar radii away)
gravitationally distorts the star and results in a flux modulation twice per
orbit. The ellipsoidal variations can confuse interpretation of the planetary
phase curve if not self-consistently included in the modeling. We fit the light
curve using the Roche potential approximation and derive improved planet and
orbit parameters.

7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph