Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The extreme physical properties of the CoRoT-7b super-Earth   The search for rocky exoplanets plays an important role in our quest for
extra-terrestrial life. Here, we discuss the extreme physical properties
possible for the first characterized rocky super-Earth, CoRoT-7b (R_pl = 1.58
\pm 0.10 R_Earth, Mpl = 6.9 \pm 1.2 M_Earth). It is extremely close to its star
(a = 0.0171 AU = 4.48 R_st), with its spin and orbital rotation likely
synchronized. The comparison of its location in the (Mpl, Rpl) plane with the
predictions of planetary models for different compositions points to an
Earth-like composition, even if the error bars of the measured quantities and
the partial degeneracy of the models prevent a definitive conclusion. The
proximity to its star provides an additional constraint on the model. It
implies a high extreme-UV flux and particle wind, and the corresponding
efficient erosion of the planetary atmosphere especially for volatile species
including water. Consequently, we make the working hypothesis that the planet
is rocky with no volatiles in its atmosphere, and derive the physical
properties that result. As a consequence, the atmosphere is made of rocky
vapours with a very low pressure (P \leq 1.5 Pa), no cloud can be sustained,
and no thermalisation of the planetary is expected. The dayside is very hot
(2474 \leq 71 K at the sub-stellar point) while the nightside is very cold (50
to 75 K). The sub-stellar point is as hot as the tungsten filament of an
incandescent bulb, resulting in the melting and distillation of silicate rocks
and the formation of a lava ocean. These possible features of CoRoT-7b could be
common to many small and hot planets, including the recently discovered
Kepler-10b. They define a new class of objects that we propose to name
"Lava-ocean planets".

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The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
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The categories of this paper are: chao-dyn
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The categories of this paper are: stat
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: q-alg
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The categories of this paper are: plasm-ph
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ph
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-th
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The categories of this paper are: cond-mat
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The categories of this paper are: supr-con
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The categories of this paper are: mtrl-th