Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: HD 5388 b is a 69 M_Jup companion instead of a planet   We examined six exoplanet host stars with non-standard Hipparcos astrometric
solution, which may be indicative of unrecognised orbital motion. Using
Hipparcos intermediate astrometric data, we detected the astrometric orbit of
HD 5388 at a significance level of 99.4 % (2.7 sigma). HD 5388 is a
metal-deficient star and hosts a planet candidate with a minimum mass of 1.96
M_J discovered in 2010. We determined its orbit inclination to be i = 178.3
+0.4/-0.7 deg and the corresponding mass of its companion HD 5388 b to be M_2 =
69 +/- 20 M_J. The orbit is seen almost face-on and the companion mass lies at
the upper end of the brown-dwarf mass range. A mass lower than 13 M_J was
excluded at the 3-sigma level. The astrometric motions of the five other stars
had been investigated by other authors revealing two planetary companions, one
stellar companion, and two statistically insignificant orbits. We conclude that
HD 5388 b is not a planet but most likely a brown-dwarf companion. In addition,
we find that the inclinations of the stellar rotation axis and the companion's
orbital axis differ significantly.

26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin