Glory revealed in disk-integrated photometry of Venus

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

Symmetry limit properties of a priori mixing amplitudes for non-leptonic and weak radiative decays of hyperons

We show that the so-called parity-conserving amplitudes predicted in the a priori mixing scheme for non-leptonic and weak radiative decays of hyperons vanish in the strong-flavor symmetry limit

The complex structure of HH 110 as revealed from Integral Field Spectroscopy

HH 110 is a rather peculiar Herbig-Haro object in Orion that originates due to the deflection of another jet (HH 270) by a dense molecular clump, instead of being directly ejected from a young stellar object. Here we present new results on the kinematics and physical conditions of HH 110 based on Integral Field Spectroscopy. The 3D spectral data cover the whole outflow extent (~4.5 arcmin, ~0.6 pc at a distance of 460 pc) in the spectral range 6500-7000 \AA. We built emission-line intensity maps of H$\alpha$, [NII] and [SII] and of their radial velocity channels. Furthermore, we analysed the spatial distribution of the excitation and electron density from [NII]/H$\alpha$, [SII]/H$\alpha$, and [SII] 6716/6731 integrated line-ratio maps, as well as their behaviour as a function of velocity, from line-ratio channel maps. Our results fully reproduce the morphology and kinematics obtained from previous imaging and long-slit data. In addition, the IFS data revealed, for the first time, the complex spatial distribution of the physical conditions (excitation and density) in the whole jet, and their behaviour as a function of the kinematics. The results here derived give further support to the more recent model simulations that involve deflection of a pulsed jet propagating in an inhomogeneous ambient medium. The IFS data give richer information than that provided by current model simulations or laboratory jet experiments. Hence, they could provide valuable clues to constrain the space parameters in future theoretical works.Comment: 12 pages, 15 figures Accepted in MNRA

Isocausal spacetimes may have different causal boundaries

We construct an example which shows that two isocausal spacetimes, in the sense introduced by Garc\'ia-Parrado and Senovilla, may have c-boundaries which are not equal (more precisely, not equivalent, as no bijection between the completions can preserve all the binary relations induced by causality). This example also suggests that isocausality can be useful for the understanding and computation of the c-boundary.Comment: Minor modifications, including the title, which matches now with the published version. 12 pages, 3 figure

Algunos métodos para la prosprección de estaño

[Resumen] Se hace una síntesis de datos, fundamentalmente bibliográficos, en relación con la geoquímica del Sn en áreas graníticas mineralizadas y con fines primordialmente prácticos para su uso en prospección. El trabajo se divide en dos partes: por un lado se estudian las aureolas de dispersión primarias del Sn en los propios granitoides, y por otro las aureolas de dispersión secundaria en los productos de su denudación[Abstract] In this work a synthesis of bibliographic information concerning to the granitoides geochemistry relation with tin deposits is made for practical purposes in their use in prospection. On the other hand the tin primary dispersion aureoles in the granitic rocks are studied, on the another hand the tin secundary dispersion aureoles are considered in their denudation products

Integral Field Spectroscopy of HH 262: The Spectral Atlas

HH 262 is a group of emitting knots displaying an "hour-glass" morphology in the Halpha and [SII] lines, located 3.5' to the northeast of the young stellar object L1551-IRS5, in Taurus. We present new results of the kinematics and physical conditions of HH 262 based on Integral Field Spectroscopy covering a field of 1.5'x3', which includes all the bright knots in HH 262. These data show complex kinematics and significant variations in physical conditions over the mapped region of HH 262 on a spatial scale of <3". A new result derived from the IFS data is the weakness of the [NII] emission (below detection limit in most of the mapped region of HH 262), including the brightest central knots. Our data reinforce the association of HH 262 with the redshifted lobe of the evolved molecular outflow L1551-IRS5. The interaction of this outflow with a younger one, powered by L1551 NE, around the position of HH 262 could give rise to the complex morphology and kinematics of HH 262.Comment: Accepted for publication in MNRA

Anderson localization in a periodic photonic lattice with a disordered boundary

We investigate experimentally the light evolution inside a two-dimensional finite periodic array of weakly- coupled optical waveguides with a disordered boundary. For a completely localized initial condition away from the surface, we find that the disordered boundary induces an asymptotic localization in the bulk, centered around the initial position of the input beam.Comment: 3 pages, 4 figure

Multilayer hazes over Saturn’s hexagon from Cassini ISS limb images

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Predicting grower choices in a regulated environment

The analysis of farmers’ decision making process in the framework of agricultural policy is particularly complex as they take action within a structure of interacting opportunities, preferences, benefits and social factors which ultimately account for their behavior. This paper will study viticulturists’ behaviour vis-à-vis this scenario. Their decisions in the face of different possible alternatives are analysed using a multinomial logit model and a sample of 74,502 plots in Castilla-La Mancha (Spain). The conclusion is that viticulturists from this region are more prone to maintaining the status quo in their plots due to the current public support security issues, uncertain scenarios and their natural risk aversion