Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Stellar Obliquities in Long-period Exoplanet Systems (SOLES) I: The
  Spin-Orbit Alignment of K2-140 b   Obliquity measurements for stars hosting relatively long-period giant planets
with weak star-planet tidal interactions may play a key role in distinguishing
between formation theories for shorter-period hot Jupiters. Few such obliquity
measurements have been made to date due to the relatively small sample of known
wide-orbiting, transiting Jovian-mass planets and the challenging nature of
these targets, which tend to have long transit durations and orbit faint stars.
We report a measurement of the Rossiter-McLaughlin effect across the transit of
K2-140 b, a Jupiter-mass planet with period $P=6.57$ days orbiting a $V=12.6$
star. We find that K2-140 is an aligned system with projected spin-orbit angle
$\lambda=0.5\pm9.7$ degrees, suggesting a dynamically cool formation history.
This observation builds towards a population of tidally detached giant planet
spin-orbit angles that will enable a direct comparison with the distribution of
close-orbiting hot Jupiter orbital configurations, elucidating the prevalent
formation mechanisms of each group.

26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an