Bibcode
Niedzielski, Andrzej; Wolszczan, Alex; Nowak, G.; Zieliński, Paweł; Adamów, Monika; Gettel, Sara
Bibliographical reference
The Astrophysics of Planetary Systems: Formation, Structure, and Dynamical Evolution, Proceedings of the International Astronomical Union, IAU Symposium, Volume 276, p. 445-447
Advertised on:
11
2011
Citations
1
Refereed citations
1
Description
Searches for planets around giants represent an essential complement to
'traditional' surveys, because they furnish information about properties
of planetary systems around stars that are the descendants of the A-F
main sequence (MS) stars with masses as high as ~5 M⊙. As
the stars evolve off the MS, their effective temperatures and rotation
rates decrease to the point that their radial velocity variations can be
measured with a few ms-1 precision. This offers an excellent
opportunity to improve our understanding of the population of planets
around stars that are significantly more massive than the Sun, without
which it would be difficult to produce abroad, integrated picture of
planet formation and evolution. Since 2001, about 30 such objects have
been identified, including our five published HET detections
(Niedzielski et al. 2007; Niedzielski et al. 2009a; Niedzielski et al.
2009b). Our work has produced the tightest orbit of a planet orbiting a
K-giant identified so far (0.6 AU), and the first convincing evidence
for a multiplanet system around such as star (Niedzielski et al. 2009a).
Our most recent discoveries (Niedzielski et al. 2009b) have identified
new multiplanet systems, including a very intriguing one of two brown
dwarf-mass bodies orbiting a 2.8M⊙, K2 giant. This
particular detection challenges the standard interpretation of the
so-called brown dwarf desert known to exist in the case of solar-mass
stars. Along with discoveries supplied by other groups, our work has
substantially added to the emerging evidence that stellar mass
positively correlates with masses of substellar companions, all the way
from red dwarfs to intermediate-mass stars. We present current status
and forthcoming results from the Pennsylvania-Toruń Search for
Planets performed with the Hobby-Eberly Telescope (HET) since 2004.