2,228 research outputs found

    Glory revealed in disk-integrated photometry of Venus

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    Context. Reflected light from a spatially unresolved planet yields unique insight into the overall optical properties of the planet cover. Glories are optical phenomena caused by light that is backscattered within spherical droplets following a narrow distribution of sizes; they are well known on Earth as localised features above liquid clouds. Aims. Here we report the first evidence for a glory in the disk-integrated photometry of Venus and, in turn, of any planet. Methods. We used previously published phase curves of the planet that were reproduced over the full range of phase angles with model predictions based on a realistic description of the Venus atmosphere. We assumed that the optical properties of the planet as a whole can be described by a uniform and stable cloud cover, an assumption that agrees well with observational evidence. Results. We specifically show that the measured phase curves mimic the scattering properties of the Venus upper-cloud micron-sized aerosols, also at the small phase angles at which the glory occurs, and that the glory contrast is consistent with what is expected after multiple scattering of photons. In the optical, the planet appears to be brighter at phase angles of 11-13 deg than at full illumination; it undergoes a maximum dimming of up to 10 percent at phases in between. Conclusions. Glories might potentially indicate spherical droplets and, thus, extant liquid clouds in the atmospheres of exoplanets. A prospective detection will require exquisite photometry at the small planet-star separations of the glory phase angles.Comment: In press. Astronomy & Astrophysics. Letter to the Editor; 201

    ReconstrucciĂłn de la dinĂĄmica del sistema barrera-lagoon del Parque Nacional de las Islas CĂ­es a partir de su registro sedimentario

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    XV lnternational A.P.L.E. Symposium of Palynolog

    InquisiciĂłn, poder y escritura femenina en tiempos del conde-duque de Olivares (1621-1643): el caso de Teresa Valle de la Cerda

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    This thesis examines the importance of women in political and cultural life at the Spanish court through the case of Teresa Valle, spiritual counsellor of Olivares, the favourite of King Philip IV (1621–1643). Scholars have assumed that women in Golden Age Spain played only a minor role in high Baroque politics and culture; my research demonstrates this to be a partial and insufficient view. Through an analysis of diverse primary sources such as letters, literary writings, and Inquisition records I show how relations between noblemen and religious women formed a key aspect of Baroque patronage and exchange, forming an essential tool of publicity and power for the former, and a way of access to the literary domain for the latter. Teresa Valle founded a convent in Madrid with the help of her patrons. The fame as visionary achieved by her aroused the wrath of some of the nuns of her convent, who denounce her to the Holy Office. She was condemned and the enemy factions of her powerful friends used the scandal to destruct their public image. In order to defence her honour and the moral integrity of her patrons Teresa addressed three treatises to the inquisitors and one confessional writing to the King. At the heart of the thesis there is a study of the writings that Teresa produced during this period, revealing her emerging literary identity, which I tried to elucidate and analyse. The nun®s trip into literature also allows me to define new paths of understanding female writing in Golden Age Spain and clarify the discursive strategies that religious women negotiated

    Yellowtail Flounder Length at Maturity in the Grand Bank (1995-98)

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    In this paper yellowtail length at maturity estimates based data collected in the spring Spanish surveys in the Regulatory Area of Divisions 3NO are presented. Female length at 50 % maturity decreased from 35 cm in 1995 to 23 cm in 1998. In males, this parameter decreased from 23 cm in 1995 to 19 cm in 1998. The differences in L50 estimates in females were significant between 1997 and the previous years , and between 1998 and both 1996 and 1995, and were not significant between 1997 and 1998. In males, differences were significant between all the years, except between 1997 and 1998. The covariance analysis between the linearized maturity curves were highly significant in both sexes

    Bandgap and effective mass of epitaxial cadmium oxide

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    The bandgap and band-edge effective mass of single crystal cadmium oxide, epitaxially grown by metal-organic vapor-phase epitaxy, are determined from infrared reflectivity, ultraviolet/visible absorption, and Hall effect measurements. Analysis and simulation of the optical data, including effects of band nonparabolicity, Moss-Burstein band filling and bandgap renormalization, reveal room temperature bandgap and band-edge effective mass values of 2.16±0.02 eV and 0.21±0.01m0 respectively
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