Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Direct Imaging of Planet Transit Events   Exoplanet transit events are attractive targets for the ultrahigh-resolution
capabilities afforded by optical interferometers. The intersection of two
developments in astronomy enable direct imaging of exoplanet transits: first,
improvements in sensitivity and precision of interferometric instrumentation;
and second, identification of ever-brighter host stars. Efforts are underway
for the first direct high-precision detection of closure phase signatures with
the CHARA Array and Navy Precision Optical Interferometer. When successful,
these measurements will enable recovery of the transit position angle on the
sky, along with characterization of other system parameters, such as stellar
radius, planet radius, and other parameters of the transit event. This
technique can directly determine the planet's radius independent of any outside
observations, and appears able to improve substantially upon other
determinations of that radius; it will be possible to extract wavelength
dependence of that radius determination, for connection to characterization of
planetary atmospheric composition & structure. Additional directly observed
parameters - also not dependent on transit photometry or spectroscopy - include
impact parameter, transit ingress time, and transit velocity.

31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ