... A self-consistent model for a thin accretion disk with turbulent convection is presented. ... In the gas pressure region, two distinct solutions are obtained. ... R : radiation pressure region, strong convection. ... It is interesting to note that the trend of convection to stabilize the radiation pressure dominated region, is evident even in models in which the disk viscosity is described by an parameter and the convective flux by the mixing length approach (Milsom, Chen, & Taam 1994). ...

... Mass loss Recipes | ... Mass Loss is the most important "driver" of stellar evolution in massive stars. ... The final goal is to predict mass loss over the entire evolution of a massive star at all cosmological epochs. ... Very Massive Stars are objects up to 300 times the mass of the Sun. ... Mass-loss rates increase dramatically when objects cross a critical Eddington Gamma factor (Vink et al. ... I have recently edited a book on "Very Massive Stars" including a mass-loss "chapter" . ...

... I note that "Z" plays an important role in what the ALFA surveys will look for: . ... low Z . nearby low mass . ... Arecibo . ... ADBS (Arecibo Dual Beam Survey): Rosenberg & Schneider 2002. ... A few sources with unobvious optical counterparts. ... Coverage wins for volume, but if you do a shallow survey you are sampling only the nearby volume at low masses. ... So need artificial test sources to find completeness. ... Total volume within survey in which source could have been detected. ...

... Tonight's Sky . ... Behemoth black hole found in an unlikely place . Gravitational wave search provides insights into galaxy evolution and mergers . ... galaxies . ... Mysterious quasar sequence explained . ... A growing black hole, called a quasar, can be seen at the center of a faraway galaxy in this artist's concept. ... Quasars are supermassive black holes that live at the centers of distant massive galaxies. ... Only registered members of Astronomy.com are allowed to comment on this article. ...

... Recherche dans le site : . Ciel Espace, le magazine qui vous guide toujours plus loin . ... Ciel Espace, nouvelle formule, c'est . des actualitУ?s . ... Accueil Lire/Voir/Ecouter Lire/Voire/Ecouter . ... Lire/Voir/Ecouter . ... Mais il s'emploie autant que possible Уљ intУ?grer des У?lУ?ments terrestres dans ses compositions photographiques. ... Nous ne saurions donc que trop recommander ce livre aux amateurs d'images du ciel qui veulent dУ?couvrir une pratique hors des sentiers battus. ...

... Stars, in many ways, are just like people. ... Once, people regarded the Sun as a different sort of object than the stars. ... But over the past few centuries astronomers have come to recognize that the Sun is just one middle-aged member of the vast family of stars. ... By studying the Sun, the closest star, scientists have learned about all stars. ... Though we weren't around to witness the birth of our provider, we can read its early life history in the stars. ... The Sun was born. ...

... ЗЕМЛЯ, третья от Солнца большая планета Солнечной системы. ... Вращение Земли вокруг собственной оси происходит со средней угловой скоростью 7,292115ћ10-5рад/с, что примерно соответствует периоду в 23 ч 56 мин 4,1 с. Линейная скорость поверхности Земли на экваторе -около 465 м/с. Ось вращения наклонена к плоскости эклиптики под углом 66њ 33' 22''. ... На глубину примерно от 35 до 2885 км простирается мантия Земли, которую называют также силикатной оболочкой. ... Над поверхностью Земли . ...