A Giant Planet Around a Metal-poor Star of Extragalactic Origin
arXiv:1011.6376 · doi:10.1126/science.1193342
Abstract
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.
32 pages, 9 Figures
References in corpus (11)
- The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
- The On/Off Nature of Star-Planet Interactions
- The sdB+M Eclipsing System HW Virginis and its Circumbinary Planets
- Falling Transiting Extrasolar Giant Planets
- Halo Star Streams in the Solar Neighborhood
- The Role of Planet Accretion in Creating the Next Generation of Red Giant Rapid Rotators
- Discovery of a planet around the K giant star 4 UMa
- Rotation and Macroturbulence in Metal-poor Field Red Giant and Red Horizontal Branch Stars
- Line Broadening in Field Metal-poor Red Giant and Red Horizontal Branch Stars
- Solar-like oscillations in a metal-poor globular cluster with the HST
- Orbital evolution with white-dwarf kicks
Cited by in corpus (8)
- Foretellings of Ragnarök: World-engulfing Asymptotic Giants and the Inheritance of White Dwarfs
- An ancient extrasolar system with five sub-Earth-size planets
- A planetary system and a highly eccentric brown dwarf around the giant stars HIP67851 and HIP97233
- Planet Traps and First Planets: the Critical Metallicity for Gas Giant Formation
- An Extreme-AO Search for Giant Planets around a White Dwarf --VLT/SPHERE performance on a faint target GD 50
- Modeling gravitational instabilities in self-gravitating protoplanetary disks with adaptive mesh refinement techniques
- Planetary companions around the metal-poor star HIP 11952
- Precision Astrometry of the Exoplanet Host Candidate GD 66