Скачать или смотреть Exoplanet Atmospheres at high spectral resolution - Matteo Brogi

After only two decades from the first discoveries, we know today about 2,000 planets orbiting stars other than the Sun. In order to truly understand the nature and the properties of these exoplanets, we need to study their atmospheres, a task performed nowadays with a range of observational techniques. In this talk I will focus on groundbased high resolution R larger than 20,000 spectroscopy, which has recently excelled in delivering robust molecular detections and estimating their relative abundances. I will review the major breakthroughs achieved in recent years, among which are the first atmospheric detections for nontransiting planets, and the unprecedented measurements of their true masses and orbital inclinations. I will then focus on the recent detection of the rotation and atmospheric winds of HD 189733b, a Jupitersize planet orbiting a K12V star in 2.2 days. We measure a combined absorption of CO and H2O lines with a confidence level of 7.6 sigma. The signal is obtained by cross correlating the data with theoretical spectra, and is maximized for a planet rotational velocity of 3.5+1.1 -2.6 km/s. This corresponds to a planet rotational period of 1.7+4.9 -0.4 days, consistent with the known planet orbital period of 2.2 days and therefore with tidal locking. Although we rule out at high confidence 3 sigma planet rotation faster than 1.1 days, norotation is only marginally excluded 1.2sigma. Finally, we detect a small 1.7 km/s daytonight side winds. Compared to previouslydetected sodium doppler shifted by 8 km/s, it likely implies a strong shear between the atmospheric pressures probed by these high dispersion observations 0.1-0.001 bar, and the outermost atmospheric layers where the core of the sodium lines is formed.