Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Masses for the seven planets in K2-32 and K2-233. Four diverse planets
  in resonant chain and the first young rocky worlds   High-precision planetary densities are key to derive robust atmospheric
properties for extrasolar planets. Measuring precise masses is the most
challenging part, especially in multi-planetary systems. We measure the masses
and densities of a four-planet near resonant chain system (K2-32), and a young
($\sim400$ Myr old) planetary system consisting of three close-in small planets
(K2-233). We obtained 199 new HARPS observations for K2-32 and 124 for K2-233
covering a more than three year baseline. We find that K2-32 is a compact
scaled-down version of the Solar System's architecture, with a small rocky
inner planet (M$_e=2.1^{+1.3}_{-1.1}$~M$_{\oplus}$, P$_e\sim4.35$~days)
followed by an inflated Neptune-mass planet
(M$_b=15.0^{+1.8}_{-1.7}$~M$_{\oplus}$, P$_b\sim8.99$~days) and two external
sub-Neptunes (M$_c=8.1\pm2.4$~M$_{\oplus}$, P$_c\sim20.66$~days;
M$_d=6.7\pm2.5$~M$_{\oplus}$, P$_d\sim31.72$~days). K2-32 becomes one of the
few multi-planetary systems with four or more planets known with measured
masses and radii. Additionally, we constrain the masses of the three planets in
K2-233. For the two inner Earth-size planets we constrain their masses to be
smaller than M$_b<11.3$ M$_{\oplus}$ (P$_b\sim2.47$~days), M$_c<12.8$
M$_{\oplus}$ (P$_c\sim7.06$~days). The outer planet is a sub-Neptune size
planet with an inferred mass of M$_d=8.3^{+5.2}_{-4.7}$ M$_{\oplus}$
(M$_d<21.1$ M$_{\oplus}$, P$_d\sim24.36$~days). Our observations of these two
planetary systems confirm for the first time the rocky nature of two planets
orbiting a young star, with relatively short orbital periods ($<7$ days). They
provide key information for planet formation and evolution models of telluric
planets. Additionally, the Neptune-like derived masses of the three planets
K2-32 b, c, d puts them in a relatively unexplored regime of incident flux and
planet mass, key for transmission spectroscopy studies.

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The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
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The categories of this paper are: cond-mat
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The categories of this paper are: quant-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: math
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-th
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-th