Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The prevalence of dust on the exoplanet HD 189733b from Hubble and
  Spitzer observations   The hot Jupiter HD189733b is the most extensively observed exoplanet. Its
atmosphere has been detected and characterised in transmission and eclipse
spectroscopy, and its phase curve measured at several wavelengths. This paper
brings together results of our campaign to obtain the complete transmission
spectrum of the atmosphere of this planet from UV to IR with HST, using STIS,
ACS and WFC3. We provide a new tabulation of the transmission spectrum across
the entire visible and IR range. The radius ratio in each wavelength band was
rederived to ensure a consistent treatment of the bulk transit parameters and
stellar limb-darkening. Special care was taken to correct for, and derive
realistic estimates of the uncertainties due to, both occulted and unocculted
star spots. The combined spectrum is very different from the predictions of
cloud-free models: it is dominated by Rayleigh scattering over the whole
visible and near infrared range, the only detected features being narrow Na and
K lines. We interpret this as the signature of a haze of condensate grains
extending over at least 5 scale heights. We show that a dust-dominated
atmosphere could also explain several puzzling features of the emission
spectrum and phase curves, including the large amplitude of the phase curve at
3.6um, the small hot-spot longitude shift and the hot mid-infrared emission
spectrum. We discuss possible compositions and derive some first-order
estimates for the properties of the putative condensate haze/clouds. We finish
by speculating that the dichotomy between the two observationally defined
classes of hot Jupiter atmospheres, of which HD189733b and HD209458b are the
prototypes, might not be whether they possess a temperature inversion, but
whether they are clear or dusty. We also consider the possibility of a
continuum of cloud properties between hot Jupiters, young Jupiters and L-type
brown dwarfs.

28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc