Bibcode
Niedzielski, A.; Nowak, G.; Adamów, M.; Wolszczan, A.
Bibliographical reference
The Astrophysical Journal, Volume 707, Issue 1, pp. 768-777 (2009).
Advertised on:
12
2009
Journal
Citations
81
Refereed citations
66
Description
We present the discovery of substellar-mass companions to three stars by
the ongoing Penn State-Toruń Planet Search conducted with the 9.2
m Hobby-Eberly Telescope. The K2-dwarf, BD+14 4559, has a 1.5
MJ minimum mass companion with the orbital period of 269 days
and shows a non-linear, long-term radial velocity (RV) trend, which
indicates a possible presence of another planet-mass body in the system.
The K3-giant, HD 240210, exhibits RV variations that require modeling
with multiple orbits, but the available data are not yet sufficient to
do it unambiguously. A tentative, one-planet model calls for a 5.2
MJ minimum mass planet in a 502 day orbit around the star.
The most massive of the three stars, the K2-giant, BD+20 2457, whose
estimated mass is 2.8 ± 1.5 M sun, has two companions
with the respective minimum masses of 21.4 MJ and 12.5
MJ and orbital periods of 380 and 622 days. Depending on the
unknown inclinations of the orbits, the currently very uncertain mass of
the star, and the dynamical properties of the system, it may represent
the first detection of two brown dwarf-mass companions orbiting a giant.
The existence of such objects will have consequences for the
interpretation of the so-called brown dwarf desert known to exist in the
case of solar-mass stars.