Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Final Report for SAG 21: The Effect of Stellar Contamination on
  Space-based Transmission Spectroscopy   Study Analysis Group 21 (SAG21) of the Exoplanet Exploration Program Analysis
Group (ExoPAG) was organized to study the effect of stellar contamination on
space-based transmission spectroscopy, a method for studying exoplanetary
atmospheres by measuring the wavelength-dependent radius of a planet as it
transits its star. Transmission spectroscopy relies on a precise understanding
of the spectrum of the star being occulted. However, stars are not homogeneous,
constant light sources but have temporally evolving photospheres and
chromospheres with inhomogeneities like spots, faculae, and plages. This SAG
has brought together an interdisciplinary team of more than 100 scientists,
with observers and theorists from the heliophysics, stellar astrophysics,
planetary science, and exoplanetary atmosphere research communities, to study
the current needs that can be addressed in this context to make the most of
transit studies from current NASA facilities like HST and JWST. The analysis
produced 14 findings, which fall into three Science Themes encompassing (1) how
the Sun is used as our best laboratory to calibrate our understanding of
stellar heterogeneities ("The Sun as the Stellar Benchmark"), (2) how stars
other than the Sun extend our knowledge of heterogeneities ("Surface
Heterogeneities of Other Stars") and (3) how to incorporate information
gathered for the Sun and other stars into transit studies ("Mapping Stellar
Knowledge to Transit Studies").

5
The categories of this paper are: gr-qc
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The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: cs
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The categories of this paper are: nucl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-alg
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The categories of this paper are: acc-phys
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The categories of this paper are: plasm-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: quant-ph
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The categories of this paper are: physics