Evidence of a massive planet candidate orbiting the young active K5V star BD+20 1790

Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory (ESO). DOI: 10.1051/0004-6361/200811000Context. BD+20 1790 is a young active, metal-rich, late-type K5Ve star. We have undertaken a study of stellar activity and kinematics for this star over the past few years. Previous results show a high level of stellar activity, with the presence of prominence-like structures, spots on the surface, and strong flare events, despite the moderate rotational velocity of the star. In addition, radial velocity variations with a semi-amplitude of up to 1 km s-1 were detected. Aims. We investigate the nature of these radial velocity variations, in order to determine whether they are due to stellar activity or the reflex motion of the star induced by a companion. Methods. We have analysed high-resolution echelle spectra by measuring stellar activity indicators and computing radial velocity (RV) and bisector velocity spans. Two-band photometry was also obtained to produce the light curve and determine the photometric period. Results. Based upon the analysis of the bisector velocity span, as well as spectroscopic indices of chromospheric indicators, Ca ii H & K, Hα, and taking the photometric analysis into account, we report that the best explanation for the RV variation is the presence of a substellar companion. The Keplerian fit of the RV data yields a solution for a close-in massive planet with an orbital period of 7.78 days. The presence of the close-in massive planet could also be an interpretation for the high level of stellar activity detected. Since the RV data are not part of a planet search programme, we can consider our results as a serendipitous evidence of a planetary companion. To date, this is the youngest main sequence star for which a planetary candidate has been reported.Peer reviewe

Large-scale iterated singing experiments reveal oral transmission mechanisms underlying music evolution

Speech and song have been transmitted orally for countless human generations, changing over time under the influence of biological, cognitive, and cultural pressures. Cross-cultural regularities and diversities in hu- man song are thought to emerge from this transmission process, but testing how underlying mechanisms contribute to musical structures remains a key challenge. Here, we introduce an automatic online pipeline that streamlines large-scale cultural transmission experiments using a sophisticated and naturalistic modal- ity: singing. We quantify the evolution of 3,424 melodies orally transmitted across 1,797 participants in the United States and India. This approach produces a high-resolution characterization of how oral transmission shapes melody, revealing the emergence of structures that are consistent with widespread musical features observed cross-culturally (small pitch sets, small pitch intervals, and arch-shaped melodic contours). We show how the emergence of these structures is constrained by individual biases in our participants—vocal constraints, working memory, and cultural exposure—which determine the size, shape, and complexity of evolving melodies. However, their ultimate effect on population-level structures depends on social dynamics taking place during cultural transmission. When participants recursively imitate their own productions (indi- vidual transmission), musical structures evolve slowly and heterogeneously, reflecting idiosyncratic musical biases. When participants instead imitate others’ productions (social transmission), melodies rapidly shift to- ward homogeneous structures, reflecting shared structural biases that may underpin cross-cultural variation. These results provide the first quantitative characterization of the rich collection of biases that oral transmis- sion imposes on music evolution, giving us a new understanding of how human song structures emerge via cultural transmission

Linfoma de tejido linfoide asociado al bronquio (BALT)

Se presentan dos casos de linfoma no hodgkiniano endobronquial o de tejido linfoide asociado al bronquio (BALT), dado que se trata de una entidad extremadamente rara o infraestimada. Se hace hincapié en la necesidad de realizar un estudio endoscópico en aquellos pacientes diagnosticados de linfoma con clínica que haga pensar en la presencia de enfermedad bronquia

Possible Atmospheric Diversity of Low Mass Exoplanets – Some Central Aspects

Exoplanetary science continues to excite and surprise with its rich diversity. We discuss here some key aspects potentially influencing the range of exoplanetary terrestrial-type atmospheres which could exist in nature. We are motivated by newly emerging observations, refined approaches to address data degeneracies, improved theories for key processes affecting atmospheric evolution and a new generation of atmospheric models which couple physical processes from the deep interior through to the exosphere and consider the planetary-star system as a whole. Using the Solar System as our guide we first summarize the main processes which sculpt atmospheric evolution then discuss their potential interactions in the context of exoplanetary environments. We summarize key uncertainties and consider a diverse range of atmospheric compositions discussing their potential occurrence in an exoplanetary context