Jason W. Barnes 2009 ApJ 705 683 doi:10.1088/0004-637X/705/1/683
Jason W. Barnes1
Show affiliationsMain-sequence stars earlier than spectral-type ~F6 or so are expected to rotate rapidly due to their radiative exteriors. This rapid rotation leads to an oblate stellar figure. It also induces the photosphere to be hotter (by up to several thousand kelvin) at the pole than at the equator as a result of a process called gravity darkening that was first predicted by von Zeipel. Transits of extrasolar planets across such a non-uniform, oblate disk yield unusual and distinctive lightcurves that can be used to determine the relative alignment of the stellar rotation pole and the planet orbit normal. This spin-orbit alignment can be used to constrain models of planet formation and evolution. Orderly planet formation and migration within a disk that is coplanar with the stellar equator will result in spin-orbit alignment. More violent planet-planet scattering events should yield spin-orbit misaligned planets. Rossiter-McLaughlin measurements of transits of lower-mass stars show that some planets are spin-orbit aligned, and some are not. Since Rossiter-McLaughlin measurements are difficult around rapid rotators, lightcurve photometry may be the best way to determine the spin-orbit alignment of planets around massive stars. The Kepler mission will monitor ~104 of these stars within its sample. The lightcurves of any detected planets will allow us to probe the planet formation process around high-mass stars for the first time.
eclipses; stars: individual (Altair); techniques: photometric
Issue 1 (2009 November 1)
Received 2009 July 22, accepted for publication 2009 September 17
Published 2009 October 14
Jason W. Barnes 2009 ApJ 705 683
Francisco Barradas-Solas 2007 Phys. Educ. 42 9
A Lamacraft et al 2004 J. Phys. A: Math. Gen. 37 L447
M Dragoman et al 2009 Nanotechnology 20 375203
Woo-Sung Jung et al 2008 EPL 81 48005
Carlos F Tolmasky and Andreas Wiegmann 1999 Inverse Problems 15 465
R Z Zhdanov 1994 J. Phys. A: Math. Gen. 27 L291
N Ryde and B Andersson 1955 Proc. Phys. Soc. B 68 1117
T R Overton and P R J Burch 1966 Phys. Med. Biol. 11 47
M Boiti et al 2001 Inverse Problems 17 515