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The visitor from an ancient galaxy: A planetary companion around an old, metal-poor red horizontal branch star

Published online by Cambridge University Press:  10 November 2011

Rainer J. Klement ,
Johny Setiawan ,
Thomas Henning ,
Hans-Walter Rix ,
Boyke Rochau ,
Jens Rodmann  and
Tim Schulze-Hartung
Rainer J. Klement
Affiliation:
Max-Planck-Institute for Astronomy Königstuhl 17, D-69121 Heidelberg, Germany email: [email protected]
Johny Setiawan
Affiliation:
Max-Planck-Institute for Astronomy Königstuhl 17, D-69121 Heidelberg, Germany email: [email protected]
Thomas Henning
Affiliation:
Max-Planck-Institute for Astronomy Königstuhl 17, D-69121 Heidelberg, Germany email: [email protected]
Hans-Walter Rix
Affiliation:
Max-Planck-Institute for Astronomy Königstuhl 17, D-69121 Heidelberg, Germany email: [email protected]
Boyke Rochau
Affiliation:
Max-Planck-Institute for Astronomy Königstuhl 17, D-69121 Heidelberg, Germany email: [email protected]
Jens Rodmann
Affiliation:
European Space Agency, Space Environment and Effects Section, ESTEC
Tim Schulze-Hartung
Affiliation:
Max-Planck-Institute for Astronomy Königstuhl 17, D-69121 Heidelberg, Germany email: [email protected]
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Abstract

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We report the detection of a planetary companion around HIP 13044, a metal-poor red horizontal branch star belonging to a stellar halo stream that results from the disruption of an ancient Milky Way satellite galaxy. The detection is based on radial velocity observations with FEROS at the 2.2-m MPG/ESO telescope. The periodic radial velocity variation of P = 16.2 days can be distinguished from the periods of the stellar activity indicators. We computed a minimum planetary mass of 1.25 Mjup and an orbital semimajor axis of 0.116 AU for the planet. This discovery is unique in three aspects: First, it is the first planet detection around a star with a metallicity much lower than few percent of the solar value; second, the planet host star resides in a stellar evolutionary stage that is still unexplored in the exoplanet surveys; third, the planetary system HIP 13044 most likely has an extragalactic origin in a disrupted former satellite of the Milky Way.

Keywords

galaxy: solar neighborhoodplanetary systems: formationstars: horizontal-branchstars: individual (HIP 13044)techniques: radial velocities
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 6 , Symposium S276: The Astrophysics of Planetary Systems: Formation, Structure, and Dynamical Evolution , October 2010 , pp. 121 - 125
Copyright
Copyright © International Astronomical Union 2011

References

Beers, T. C., Kage, J. A., Preston, G. W., & Shectman, S. A. 1990, AJ, 100, 849CrossRefGoogle Scholar
Bellazzini, M., Ibata, R., Monaco, L., Martin, N., Irwin, M. J., & Lewis, G. F. 2004, MNRAS, 354, 1263CrossRefGoogle Scholar
Belokurov, V., Zucker, D. B., Evans, N. W., Gilmore, G., Vidrih, S., et al. 2006, ApJL, 642, L137CrossRefGoogle Scholar
Binney, J. & Tremaine, S. 2008, Galactic Dynamics (Princeton University Press)CrossRefGoogle Scholar
Carlberg, J. K., Majewski, S. R., & Arras, P. 2009, ApJ, 700, 832CrossRefGoogle Scholar
Carney, B. W., Latham, D. W., Stefanik, R. P., Laird, J. B., & Morse, J. A. 2003, ApJ, 125, 293CrossRefGoogle Scholar
Carney, B. W., Latham, D. W., Stefanik, R. P., & Laird, J. B. 2008, AJ, 135, 196CrossRefGoogle Scholar
Carney, B. W., Gray, D. F., Yong, D., Latham, D. W., Manset, N., Zelman, R., & Laird, J. B. 2008, AJ, 135, 892CrossRefGoogle Scholar
Chiba, M. & Beers, T. C. 2000, AJ, 119, 2843CrossRefGoogle Scholar
Currie, T. 2009, ApJL, 694, L171CrossRefGoogle Scholar
Gregory, P. C. 2005, Bayesian Logical Data Analysis for the Physical Sciences: A Comparative Approach with ‘Mathematica’ Support (Cambridge University Press)CrossRefGoogle Scholar
Hatzes, A. P. 1996, PASP, 108, 839CrossRefGoogle Scholar
Helmi, A., White, S. D. M., de Zeeuw, P. T., & Zhao, H. 1999, Nature, 402, 53CrossRefGoogle Scholar
Heyl, J. 2007, MNRAS, 382, 915CrossRefGoogle Scholar
Ingrosso, G., Calchi Novati, S., De Paolis, F., Jetzer, Ph., Nucita, A. A., & Zakharov, A. F. 2009, MNRAS, 399, 219CrossRefGoogle Scholar
Kaufer, A., Stahl, O., Tubbesing, S., Norregaard, P., Avila, G., et al. 2000, in: Iye, M. & Moorwood, A. F. (eds.), Proc. SPIE, 4008, 459CrossRefGoogle Scholar
Kepley, A. A., Morrison, H. L., Helmi, A., Kinman, T. D., Van Duyne, J., et al. 2007, AJ, 134, 1579CrossRefGoogle Scholar
Klement, R., Rix, H.-W., Flynn, C., Fuchs, B., Beers, T. C., et al. 2009, ApJ, 698, 865CrossRefGoogle Scholar
Klement, R. J. 2010, A&AR, 18, 567Google Scholar
Marchi, S. 2007, ApJ, 666, 475CrossRefGoogle Scholar
Martin, N. F., Ibata, R. A., Bellazzini, M., Irwin, M. J., Lewis, G. F., & Dehnen, W. 2004, MNRAS, 348, 12CrossRefGoogle Scholar
Re Fiorentin, P., Helmi, A., Lattanzi, M. G., & Spagna, A. 2005, A&A, 439, 551Google Scholar
Roederer, I. U., Sneden, C., Thompson, I. B., Preston, G. W., & Shectman, S. A. 2010, ApJ, 711, 573CrossRefGoogle Scholar
Santos, N. C., Mayor, M., Benz, W., Bouchy, F., Figueira, P., et al. 2010, A&A, 512, A47Google Scholar
Sato, B., Izumiura, H., Toyota, E., et al. 2008, PASJ, 60, 539CrossRefGoogle Scholar
Soker, N. 1998, AJ, 116, 1308CrossRefGoogle Scholar
Sozzetti, A., Torres, G., Latham, D. W., et al. 2009, ApJ, 697, 544CrossRefGoogle Scholar
Stello, D. & Gilliland, R. L. 2009, AJ, 700, 949CrossRefGoogle Scholar
Xiong, D. R., Cheng, Q. L., & Deng, L. 1998, ApJ, 500, 449CrossRefGoogle Scholar
Zechmeister, M. & Kürster, M. 2009, A&A, 496, 577Google Scholar