Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The mass of Beta Pictoris c from Beta Pictoris b orbital motion   We aim to demonstrate that the presence and mass of an exoplanet can now be
effectively derived from the astrometry of another exoplanet. We combined
previous astrometry of $\beta$ Pictoris b with a new set of observations from
the GRAVITY interferometer. The orbital motion of $\beta$ Pictoris b is fit
using Markov chain Monte Carlo simulations in Jacobi coordinates. The inner
planet, $\beta$ Pictoris c, was also reobserved at a separation of 96\,mas,
confirming the previous orbital estimations. From the astrometry of planet b
only, we can (i) detect the presence of $\beta$ Pictoris c and (ii) constrain
its mass to $10.04^{+4.53}_{-3.10}\,M_{\rm Jup}$. If one adds the astrometry of
$\beta$ Pictoris c, the mass is narrowed down to $9.15^{+1.08}_{-1.06}\,M_{\rm
Jup}$. The inclusion of radial velocity measurements does not affect the
orbital parameters significantly, but it does slightly decrease the mass
estimate to $8.89^{+0.75}_{-0.75}\,M_{\rm Jup}$. With a semimajor axis of
$2.68\pm0.02$\,au, a period of $1221\pm15$ days, and an eccentricity of
$0.32\pm0.02$, the orbital parameters of $\beta$ Pictoris c are now constrained
as precisely as those of $\beta$ Pictoris b. The orbital configuration is
compatible with a high-order mean-motion resonance (7:1). The impact of the
resonance on the planets' dynamics would then be negligible with respect to the
secular perturbations, which might have played an important role in the
eccentricity excitation of the outer planet.

31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
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The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
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The categories of this paper are: cs
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The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
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The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th