In this paper, we report a refined determination of the orbital parameters and the detection of the Rossiter-McLaughlin effect of the recently discovered transiting exoplanet HD 147506b (HAT-P-2b). The large orbital eccentricity at the short orbital period of this exoplanet is unexpected and is distinguishing from other known transiting exoplanets. We performed high-precision radial velocity spectroscopic observations of HD 147506 (HAT-P-2) with the new spectrograph SOPHIE, mounted on the 1.93 m telescope at the Haute-Provence observatory (OHP). We obtained 63 new measurements, including 35 on May 14 and 20 on June 11, when the planet was transiting its parent star. The radial velocity (RV) anomaly observed illustrates that HAT-P-2b orbital motion is set in the same direction as its parent star spin. The sky-projected angle between the normal of the orbital plane and the stellar spin axis, λ = 0.2 +12.2 −12.5• , is consistent with zero. The planetary and stellar radii were re-determined, yielding R p = 0.951 +0.039 −0.053 R Jup , R s = 1.416 +0.040 −0.062 R . The mass (M p = 8.62 +0.39 −0.55 M Jup ) and radius of HAT-P-2b indicate a density of 12.5 +2.6 −3.6 g cm −3 , suggesting an object in between the known close-in planets with typical density of the order of 1 g cm −3 , and the very low-mass stars, with density greater than 50 g cm −3 .
This paper presents a new algorithm, trimor, to analyse multi‐order spectra of triple systems. The algorithm is an extension of tricor, the three‐dimensional correlation technique that derives the radial velocities of triple stellar systems from single‐order spectra. The combined correlation derived from many orders enables the detection and the measurement of radial velocities of faint tertiary companions. The paper applied trimor to the already available spectra of HD 188753, a well‐known triple system, yielding the radial velocities of the faintest star in the system. This rendered the close pair of the triple system a double‐lined spectroscopic binary, which led to a precise mass ratio and an estimate of its inclination. The close‐pair inclination is very close to the inclination of the wide orbit, consistent with the assertion that this triple system has a close to coplanar configuration.
This paper presents the case of CoRoT LRa02_E2_0121, which was initially classified as a Neptune-size transiting-planet candidate on a relatively wide orbit of 36.3 days. Follow-up observations were performed with UVES, Sandiford, SOPHIE, and HARPS. These observations revealed a faint companion in the spectra. To find the true nature of the system we derived the radial velocities of the faint companion using TODMOR -a two-dimensional correlation technique, applied to the SOPHIE spectra. Modeling the lightcurve with EBAS we discovered a secondary eclipse with a depth of ∼0.07%, indicating a diluted eclipsing binary. Combined MCMC modeling of the lightcurve and the radial velocities suggested that CoRoT LRa02_E2_0121 is a hierarchical triple system with an evolved G-type primary and an A-type:F-type grazing eclipsing binary. Such triple systems are difficult to discover.
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