Luigi Bernabò Brea (1910-1999)

Malone, C.A.T. and S.K.F. Stoddart,

Line-profile tomography of exoplanet transits - II. A gas-giant planet transiting a rapidly rotating A5 star

Most of our knowledge of extrasolar planets rests on precise radial-velocity measurements, either for direct detection or for confirmation of the planetary origin of photometric transit signals. This has limited our exploration of the parameter space of exoplanet hosts to solar- and later-type, sharp-lined stars. Here we extend the realm of stars with known planetary companions to include hot, fast-rotating stars. Planet-like transits have previously been reported in the light curve obtained by the SuperWASP survey of the A5 star HD15082 (WASP-33 V = 8.3, v sini = 86 km s-1). Here we report further photometry and time-series spectroscopy through three separate transits, which we use to confirm the existence of a gas-giant planet with an orbital period of 1.22d in orbit around HD15082. From the photometry and the properties of the planet signal travelling through the spectral line profiles during the transit, we directly derive the size of the planet, the inclination and obliquity of its orbital plane and its retrograde orbital motion relative to the spin of the star. This kind of analysis opens the way to studying the formation of planets around a whole new class of young, early-type stars, hence under different physical conditions and generally in an earlier stage of formation than in sharp-lined late-type stars. The reflex orbital motion of the star caused by the transiting planet is small, yielding an upper mass limit of 4.1MJupiter on the planet. We also find evidence of a third body of substellar mass in the system, which may explain the unusual orbit of the transiting planet. In HD 15082, the stellar line profiles also show evidence of non-radial pulsations, clearly distinct from the planetary transit signal. This raises the intriguing possibility that tides raised by the close-in planet may excite or amplify the pulsations in such stars.

Exposición Internacional 1910. Buenos Aires.: Didactic leisure and international recognition

International exhibitions were greatly responsible for the modernization of western society. The motive for these events was based on the possibility of enhancing the country’s international status abroad. The genesis of world exhibitions came from the conviction that humanity as a whole would improve the continual flow of new practical applications, the development of modern communication techniques and the social need for a medium that could acquaint the general public with changes in technology, economy and society .
Since the first national industrial exhibitions in Paris during the eighteenth century and especially starting from the first Great Exhibition in London’s Hyde Park in 1851 these international events spread steadily all over Europe and the United States, to reach Latin America in the beginnings of the twentieth century . The work of professionals such as Daniel Burnham, Werner Hegemann and Elbert Peets made the relation between exhibitions and urban transformation a much more connected one, setting a precedent for subsequent exhibitions.
In Buenos Aires, the celebration of the centennial of independence from Spain in 1910 had many meanings and repercussions. A series of factors allowed for a moment of change in the city. Official optimism, economical progress, inequality and social conflict made of this a suitable time for transformation. With the organization of the Exposición Internacional the government had, among others, one specific aim: to achieve a network of visual tools to set the feeling of belonging and provide an identity for the mixture of cultures that populated the city of Buenos Aires at the time. Another important objective of the government was to put Buenos Aires at the level of European cities.
Foreign professionals had a great influence in the conceptual and factual shaping of the exhibition and in the subsequent changes caused in the urban condition. The exhibition had an important role in the ways of thinking the city and in the leisure ideas it introduced. The exhibition, as a didactic tool, worked as a precedent for conceiving leisure spaces in the future. Urban and landscape planners such as Joseph Bouvard and Charles Thays were instrumental in great part of the design of the Exhibition, but it was not only the architects and designers who shaped the identity of the fair. Other visitors such as Jules Huret or Georges Clemenceau were responsible for giving the city an international image it did not previously have.
This paper will explore on the one hand the significance of the exhibition of 1910 for the shaping of the city and its image; and on the other hand, the role of foreign professionals and the reach these influences had.