2010/11/19 by Johny Setiawan, Rainer J. Klement, Thomas Henning +9
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph.EP #astro-ph.GA
paper · pdf · doi:10.1126/science.1193342
published as Science Express, 18 November 2010 · 32 pages, 9 Figures
openalex publication_date 2010/11/19 · arxiv created 2010/11/29 · arxiv updated 2010/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Stars in their late stage of evolution, such as horizontal branch stars, are still largely unexplored for planets. We detected a planetary companion around HIP 13044, a very metal-poor star on the red horizontal branch, on the basis of radial velocity observations with a high-resolution spectrograph at the 2.2-meter Max-Planck Gesellschaft-European Southern Observatory 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 times the mass of Jupiter and its orbital semimajor axis is 0.116 astronomical units. 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.