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arXiv · 0908.3032

The spin-orbit angle of the transiting hot jupiter CoRoT-1b

F. Pont·M. Endl·W. D. Cochran·S. I. Barnes·C. Sneden·P. J. MacQueen·C. Moutou·S. Aigrain·R. Alonso·A. Baglin·F. Bouchy·M. Deleuil·M. Fridlund·G. Hebrard·A. Hatzes.·T. Mazeh·A. Shporer
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Abstract

We measure the angle between the planetary orbit and the stellar rotation axis in the transiting planetary system CoRoT-1, with new HIRES/Keck and FORS/VLT high-accuracy photometry. The data indicate a highly tilted system, with a projected spin-orbit angle lambda = 77 +- 11 degrees. Systematic uncertainties in the radial velocity data could cause the actual errors to be larger by an unknown amount, and this result needs to be confirmed with further high-accuracy spectroscopic transit measurements. Spin-orbit alignment has now been measured in a dozen extra-solar planetary systems, and several show strong misalignment. The first three misaligned planets were all much more massive than Jupiter and followed eccentric orbits. CoRoT-1, however, is a jovian-mass close-in planet on a circular orbit. If its strong misalignment is confirmed, it would break this pattern. The high occurence of misaligned systems for several types of planets and orbits favours planet-planet scattering as a mechanism to bring gas giants on very close orbits.

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F. Pont, M. Endl, W. D. Cochran, S. I. Barnes, C. Sneden, P. J. MacQueen, C. Moutou, S. Aigrain, R. Alonso, A. Baglin, F. Bouchy, M. Deleuil, M. Fridlund, G. Hebrard, A. Hatzes., T. Mazeh, A. Shporer. 2009-11-27. The spin-orbit angle of the transiting hot jupiter CoRoT-1b. https://doi.org/10.1111/j.1745-3933.2009.00785.x

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