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TOPIC: Tau Boötis b

Blobrana

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Posts: 131433

Date: Jun 28 08:10 2012

RE: Tau Boötis b	Permalink

Title: Weighing The Non-Transiting Hot Jupiter Tau BOO b Authors: Florian Rodler, Mercedes Lopez-Morales, Ignasi Ribas We report the detection of the orbital velocity of non-transiting hot Jupiter Tau Boo b. By employing high-resolution ground-based spectroscopy around 2.3 µm during one half night, we are able to detect carbon monoxide absorption lines produced in the planet atmosphere, which shift significantly in wavelength during the course of the observations due to the orbital motion of the planet. This detection of the planetary signal results in the determination of the orbital inclination being i = 47 (+7, -6) degrees and furthermore allow us to solve for the exact planetary mass being mp = 5.6 (0.7) Jupiter masses. This clearly confirms the planetary nature of the non-transiting companion to Tau Boo. Read more (46kb, PDF) __________________

Blobrana

L

Posts: 131433

Date: Jun 28 08:07 2012

tau Bootis b	Permalink

Title: The signature of orbital motion from the dayside of the planet tau Bootis b Authors: M. Brogi, I.A.G. Snellen, R.J. de Kok, S. Albrecht, J. Birkby, E.J.W. de Mooij The giant planet orbiting tau Bootis was among the first extrasolar planets to be discovered through the reflex motion of its host star. It is one of the brightest known and most nearby planets with an orbital period of just a few days. Over the course of more than a decade, measurements of its orbital inclination have been announced and refuted, and have subsequently remained elusive until now. Here we report on the detection of carbon monoxide absorption in the thermal day-side spectrum of tau Bootis b. At a spectral resolution of R~100,000, we trace the change in the radial velocity of the planet over a large range in phase, determining an orbital inclination of i=44.5±1.5 degrees and a true planet mass of 5.95±0.28 Jupiter masses. This result extends atmospheric characterisation to non-transiting planets. The strong absorption signal points to an atmosphere with a temperature that is decreasing towards higher altitudes. This is a stark contrast to the temperature inversion invoked for other highly irradiated planets, and supports models in which the absorbing compounds believed to cause such atmospheric inversions are destroyed by the ultraviolet emission from the active host star. Read more (1965kb, PDF) __________________

Blobrana

L

Posts: 131433

Date: Jun 28 00:38 2012

Tau Boötis b	Permalink

New Way of Probing Exoplanet Atmospheres For the first time a clever new technique has allowed astronomers to study the atmosphere of an exoplanet in detail - even though it does not pass in front of its parent star. An international team has used ESO's Very Large Telescope to directly catch the faint glow from the planet Tau Boötis b. They have studied the planet's atmosphere and measured its orbit and mass precisely for the first time - in the process solving a 15-year old problem. Surprisingly, the team also finds that the planet's atmosphere seems to be cooler higher up, the opposite of what was expected. The results will be published in the 28 June 2012 issue of the journal Nature. The planet Tau Boötis b was one of the first exoplanets to be discovered back in 1996, and it is still one of the closest exoplanets known. Although its parent star is easily visible with the naked eye, the planet itself certainly is not, and up to now it could only be detected by its gravitational effects on the star. Tau Boötis b is a large "hot Jupiter"planet orbiting very close to its parent star. Read more __________________

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