A Giant Planet Around a Metal-poor Star of Extragalactic Origin
  Stars in their late stage of evolution, such as Horizontal Branch stars, are
still largely unexplored for planets. We report the detection of a planetary
companion around HIP 13044, a very metal-poor star on the red Horizontal
Branch, based on radial velocity observations with a high-resolution
spectrograph at the 2.2-m MPG/ESO telescope. The star's periodic radial
velocity variation of P=16.2 days caused by the planet can be distinguished
from the periods of the stellar activity indicators. The minimum mass of the
planet is 1.25 Jupiter masses and its orbital semi-major axis 0.116 AU. Because
HIP 13044 belongs to a group of stars that have been accreted from a disrupted
satellite galaxy of the Milky Way, the planet most likely has an extragalactic
origin.
