Misc,
Three red giants with substellar-mass companions
(Jan 28, 2015)
Abstract
We present three giant stars from the ongoing Penn State-Toruń Planet
Search with the Hobby-Eberly Telescope, which exhibit radial velocity
variations that point to a presence of planetary --mass companions around them.
BD+49 828 is a \$M=1.52 0.22\$ \$M\_ødot\$ K0 giant with a \$m
sini\$=\$1.6^+0.4\_-0.2\$ \$M\_J\$ minimum mass companion in
\$a=4.2^+0.32\_-0.2\$ AU (\$2590^+300\_-180\$d), \$e=0.35^+0.24\_-0.10\$
orbit. HD 95127, a log\$L\$/\$L\_ødot\$=\$2.28 0.38\$, \$R = 209\$
\$R\_ødot\$, \$M=1.20 0.22\$ \$M\_ødot\$ K0 giant has a \$m
sini\$=\$5.01^+0.61\_-0.44\$ \$M\_J\$ minimum mass companion in
\$a=1.28^+0.01\_-0.01\$ AU (\$482^+5\_-5\$d), \$e=0.11^+0.15\_-0.06\$ orbit.
Finally, HD 216536, is a \$M=1.36 0.38\$ \$M\_ødot\$ K0 giant with a \$m sin
i=1.47^+0.20\_-0.12\$ \$M\_J\$ minimum mass companion in
\$a=0.609^+0.002\_-0.002\$ AU (\$148.6^+0.7\_-0.7\$d),
\$e=0.38^+0.12\_-0.10\$ orbit. Both, HD 95127 b and HD 216536 b in their
compact orbits, are very close to the engulfment zone and hence prone to
ingestion in the near future. BD+49 828 b is among the longest period planets
detected with the radial velocity technique until now and it will remain
unaffected by stellar evolution up to a very late stage of its host. We discuss
general properties of planetary systems around evolved stars and planet
survivability using existing data on exoplanets in more detail.
