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Evolution of spin direction of accreting magnetic protostars and spin-orbit misalignment in exoplanetary systems

Published online by Cambridge University Press:  10 November 2011

Dong Lai
Affiliation:
Center for Space Research, Department of Astronomy, Cornell University, Ithaca, NY 14853 email: dong@astro.cornell.edu Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106
Francois Foucart
Affiliation:
Center for Space Research, Department of Astronomy, Cornell University, Ithaca, NY 14853 email: dong@astro.cornell.edu
Douglas N. C. Lin
Affiliation:
Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing, China
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Abstract

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Recent observations have shown that in many exoplanetary systems the spin axis of the parent star is misaligned with the planet's orbital axis. These have been used to argue against the scenario that short-period planets migrated to their present-day locations due to tidal interactions with their natal discs. However, this interpretation is based on the assumption that the spins of young stars are parallel to the rotation axes of protostellar discs around them. We show that the interaction between a magnetic star and its circumstellar disc can (although not always) have the effect of pushing the stellar spin axis away from the disc angular momentum axis toward the perpendicular state and even the retrograde state. Planets formed in the disc may therefore have their orbital axes misaligned with the stellar spin axis, even before any additional planet-planet scatterings or Kozai interactions take place. In general, magnetosphere–disc interactions lead to a broad distribution of the spin–orbit angles, with some systems aligned and other systems misaligned.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2011

References

Backman, D., et al. 2009, ApJ, 690, 1522Google Scholar
Chatterjee, S., et al. 2008, ApJ, 686, 580Google Scholar
Fabrycky, C. & Tremaine, S. 2007, ApJ, 669, 1298Google Scholar
Foucart, F. & Lai, D. 2011, MNRAS, 412, 2799Google Scholar
Juric, M. & Tremaine, S. 2008, ApJ, 686, 603Google Scholar
Lai, D., Foucart, F., & Lin, D. N. C. 2011, MNRAS, 412, 2790Google Scholar
Nagasawa, M., Ida, S., & Bessho, T. 2008, ApJ, 678, 498Google Scholar
Wu, Y. & Murray, N. W. 2003, ApJ, 589, 605Google Scholar
Watson, C. A., et al. 2011, MNRAS, 413, L71Google Scholar