Paper

Spatially resolved eastward winds and rotation of HD 189733b

Louden, Tom, Wheatley, Peter J

2015

Overview

We measure wind velocities on opposite sides of the hot Jupiter HD\\(\\,\\)189733b by modeling sodium absorption in high-resolution HARPS transmission spectra. Our model implicitly accounts for the Rossiter-McLaughlin effect, which we show can explain the high wind velocities suggested by previous studies. Our results reveal a strong eastward motion of the atmosphere of HD\\(\\,\\)189733b, with a redshift of$2.3^{+1.3}_{-1.5}$ $\\,\\(km\\)\\,\\(s\\)^{-1}\\( on the leading limb of the planet and a blueshift of \\)5.3^{+1.0}_{-1.4}$ $\\,\\(km\\)\\,\\(s\\)^{-1}\\( on the trailing limb. These velocities can be understood as a combination of tidally locked planetary rotation and an eastward equatorial jet; closely matching the predictions of atmospheric circulation models. Our results show that the sodium absorption of HD\\)\\,$ 189733b is intrinsically velocity broadened and so previous studies of the average transmission spectrum are likely to have overestimated the role of pressure and thermal broadening.

• Publisher: Cornell University Library, arXiv.org
• Subject: Absorption / Atmospheric circulation / Atmospheric models / Extrasolar planets / Gas giant planets / Planetary limb / Planetary rotation / Red shift / Rotation / Sorption