* Astronomy

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Extrasolar Planets

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Title: Planets around Giant Stars
Authors: A. Quirrenbach, S. Reffert, C. Bergmann

We present results from a radial-velocity survey of 373 giant stars at Lick Observatory, which started in 1999. The previously announced planets iota Dra b and Pollux b are confirmed by continued monitoring. The frequency of detected planetary companions appears to increase with metallicity. The star nu Oph is orbited by two brown dwarf companions with masses of 22.3 M_Jup and 24.5 M_Jup in orbits with a period ratio close to 6:1. It is likely that the two companions to nu Oph formed in a disk around the star.

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Amateur astronomer discovers four new planets from his office at home

An amateur astronomer is over the moon after discovering four new planets in his spare time at home.

Peter Jalowiczor, 45, has never owned a telescope but still managed to provide scientists with enough information to establish the existence of four gaseous orbs outside the solar system.

The gas worker from Rotherham, South Yorkshire, has been officially named by the University of California's Lick-Carnegie Planet Search Team as the co-discoverer of planets HD31253b, HD218566b, HD177830c and HD99492c.

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Exoplanet Orbit Database

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RE: Extrasolar Planets

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Exoplanet atmospheres

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RE: Extrasolar Planets

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Title: The Fate of Exoplanets and the Red Giant Rapid Rotator Connection
Authors: Joleen K. Carlberg, Steven R. Majewski, Phil Arras, Verne V. Smith, Katia Cunha, Dmitry Bizyaev

We have computed the fate of exoplanet companions around main sequence stars to explore the frequency of planet ingestion by their host stars during the red giant branch evolution. Using published properties of exoplanetary systems combined with stellar evolution models and Zahn's theory of tidal friction, we modelled the tidal decay of the planets' orbits as their host stars evolve. Most planets currently orbiting within 2 AU of their star are expected to be ingested by the end of their stars' red giant branch ascent. Our models confirm that many transiting planets are sufficiently close to their parent star that they will be accreted during the main sequence lifetime of the star. We also find that planet accretion may play an important role in explaining the mysterious red giant rapid rotators, although appropriate planetary systems do not seem to be plentiful enough to account for all such rapid rotators. We compare our modelled rapid rotators and surviving planetary systems to their real-life counterparts and discuss the implications of this work to the broader field of exoplanets.

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Planets where diamonds are as common as sand may exist

New forms of life may inhabit the exotic worlds encrusted with diamonds.
The possibility is raised by a Jupiter-like planet with an atmosphere that is unusually rich in carbon.
WASP-12b, which orbits a star 1,200 light years away, is too big, hot and gassy to have a surface that supports life.
But its peculiar atmospheric make-up has introduced a completely new class of carbon-rich planets to astronomers.
Scientists believe rockier, Earth-sized planets formed around the same star - and possibly others - may also be heavily composed of carbon.
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Title: The spin-orbit angles of the transiting exoplanets WASP-1b, WASP-24b, WASP-38b and HAT-P-8b from Rossiter-McLaughlin observations
Authors: E. K. Simpson (1), D. Pollacco (1), A. Collier Cameron (2), G. Hebrard (3,4), D. R. Anderson (5), S. C. C. Barros (1), I. Boisse (3), F. Bouchy (3,4), F. Faedi (1), M. Gillon (6), L. Hebb (7), F. P. Keenan (1), G. R. M. Miller (2), C. Moutou (8), D. Queloz (9), I. Skillen (10), P. Sorensen (11), H. C. Stempels (12), A. Triaud (9), C. A. Watson (1), P. A. Wilson (11,13), ((1) Queen's University Belfast, (2) University of St Andrews, (3) Institut d'Astrophysique de Paris, (4) Observatoire de Haute-Provence, (5) Keele University, (6) Universite de Liege, (7) Vanderbilt University, (8) Laboratoire d'Astrophysique de Marseille, (9) Observatoire de Geneve, (10) Isaac Newton Group of Telescopes, (11) Nordic Optical Telescope, (12) Uppsala University, (13) University of Exeter)
(Version v2)

We present observations of the Rossiter-McLaughlin effect for the transiting exoplanet systems WASP-1, WASP-24, WASP-38 and HAT-P-8, and deduce the orientations of the planetary orbits with respect to the host stars' rotation axes. The planets WASP-24b, WASP-38b and HAT-P-8b appear to move in prograde orbits and be well aligned, having sky-projected spin orbit angles consistent with zero: {\lambda} = -4.7 ±4.0°, {\lambda} = 15 + 33°/-43° and {\lambda} = -9.7 +9.0°/-7.7°, respectively. The host stars have Teff < 6250 K and conform with the trend of cooler stars having low obliquities. WASP-38b is a massive planet on a moderately long period, eccentric orbit so may be expected to have a misaligned orbit given the high obliquities measured in similar systems. However, we find no evidence for a large spin-orbit angle. By contrast, WASP-1b joins the growing number of misaligned systems and has an almost polar orbit, {\lambda} = -79 +4.5°/-4.3°. It is neither very massive, eccentric nor orbiting a hot host star, and therefore does not share the properties of many other misaligned systems.

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