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Atmospheric mass loss plays a major role in the evolution of exoplanets. This process is driven by the stellar high-energy irradiation, especially in the first hundreds of millions of years after dissipation of the proto-planetary disk. A major source of uncertainty in modeling atmospheric photoevaporation and photochemistry is due to the lack of direct measurements of the stellar flux at extreme-UV (EUV) wavelengths. Several empirical relationships have been proposed in the past to link EUV fluxes to emission levels in X-rays, but the stellar samples employed for this aim are heterogeneous, and the available scaling laws provide significantly different predictions, especially for very active stars. We present new far-UV and X-ray observations of V1298 Tau with Hubble Space Telescope/Cosmic Origins Spectrograph and XMM-Newton, aimed to determine more accurately the high-energy emission of this solar-mass pre-main-sequence star, which hosts four exoplanets. Spectroscopic data were employed to derive the plasma emission measure distribution versus temperature, from the chromosphere to the corona, and the possible variability of this irradiation on short and year-long timescales, due to magnetic activity. As a side result, we have also measured the chemical abundances of several elements in the outer atmosphere of V1298 Tau. We employ our results as a new benchmark point for the calibration of the X-ray to EUV scaling laws, and hence to predict the time evolution of the irradiation in the EUV band, and its effect on the evaporation of exo-atmospheres.

O artigo relata o entendimento atual do conjunto de textos conhecido como Economia e sociedade, procurando esclarecer em que consistia originalmente; como foi organizado nas edições anteriores por Marianne Weber e Johannes Winckelmann; como foi tratado no âmbito da nova edição da MWG. Para tanto, procura indicar como Max Weber situava os diversos textos, as diversas versões e fases de concepção e composição desses escritos. A partir daí, sistematiza os principais aspectos dos textos evidenciados na MWG, assim como os principais campos de discussão que se abrem para a pesquisa, em especial a sociologia econômica.The article reviews the current understanding of the set of texts known as Economy and Society, looking to identify the original content, how these texts were edited in previous editions by Marianne Weber and Johannes Winckelmann, and how they have been dealt with in the new edition of the MWG. These aims in mind, the text looks to show how Max Weber himself situated the various texts, including the different versions and phases of conception and composition of the writings. The article then summarizes the main aspects of the works, as evinced in the MWG, as well as the principal fields of discussion opened up for research, especially in economic sociology.