N-body U and K matrix program

Computer program was devised to compute free-fall trajectories of satellites, allowing for injection errors and midcourse velocity perturbations. Program consists of trajectory perturbing program and N-body integrating conic program which can also be used as 2-body patch conic program

Starspots and spin-orbit alignment for Kepler cool host stars

The angle between the spin axis of the host star and the orbit of its planets (i.e., the stellar obliquity) is precious information about the formation and evolution of exoplanetary systems. Measurements of the Rossiter-McLaughlin effect revealed that many stars that host a hot-Jupiter have high obliquities, suggesting that hot-Jupiter formation involves excitation of orbital inclinations. In this contribution we show how the passage of the planet over starspots can be used to measure the obliquity of exoplanetary systems. This technique is used to obtain - for the first time - the obliquity of a system with several planets that lie in a disk, Kepler-30, with the result that the star has an obliquity smaller than 10 degrees. The implications for the formation of exoplanetary systems, in particular the hot-Jupiter population, are also discussed.Comment: To appear in special edition of AN, proceedings of the Cool Stars 17 conference, Barcelona June 201

Dinámica Económica de México: Un enfoque regional (Reseña)

Se presenta en siete capítulos un análisis del crecimiento económico, los ciclos económicos y los ciclos políticos de las entidades federativas de México en las recientes décadas considerando aspectos del contexto económico internacional y nacional que los enmarca. Por lo que aporta a la literatura de la economía regional, sobre estos temas, discutiendo las principales hipótesis interpretativas al respecto mediante el uso de varias técnicas de análisis cuantitativ

Measurements of Stellar Inclinations for Kepler Planet Candidates II: Candidate Spin-Orbit Misalignments in Single and Multiple-Transiting Systems

We present a test for spin-orbit alignment for the host stars of 25 candidate planetary systems detected by the {\it Kepler} spacecraft. The inclination angle of each star's rotation axis was estimated from its rotation period, rotational line broadening, and radius. The rotation periods were determined using the {\it Kepler} photometric time series. The rotational line broadening was determined from high-resolution optical spectra with Subaru/HDS. Those same spectra were used to determine the star's photospheric parameters (effective temperature, surface gravity, metallicity) which were then interpreted with stellar-evolutionary models to determine stellar radii. We combine the new sample with the 7 stars from our previous work on this subject, finding that the stars show a statistical tendency to have inclinations near 90$^\circ$, in alignment with the planetary orbits. Possible spin-orbit misalignments are seen in several systems, including three multiple-planet systems (KOI-304, 988, 2261). Ideally these systems should be scrutinized with complementary techniques---such as the Rossiter-McLaughlin effect, starspot-crossing anomalies or asteroseismology---but the measurements will be difficult owing to the relatively faint apparent magnitudes and small transit signals in these systems.Comment: 11 pages, 9 figures, accepted for publication in Ap

Starspots, spin-orbit misalignment, and active latitudes in the HAT-P-11 exoplanetary system

We present the analysis of 4 months of Kepler photometry of the K4V star HAT-P-11, including 26 transits of its "super-Neptune" planet. The transit data exhibit numerous anomalies that we interpret as passages of the planet over dark starspots. These spot-crossing anomalies preferentially occur at two specific phases of the transit. These phases can be understood as the intersection points between the transit chord and the active latitudes of the host star, where starspots are most abundant. Based on the measured characteristics of spot-crossing anomalies, and previous observations of the Rossiter-McLaughlin effect, we find two solutions for the stellar obliquity (psi) and active latitude (l): either psi = 106 and l = 19.7, or psi = 97 and l = 67 (all in degrees). If the active latitude changes with time in analogy with the "butterfly diagram" of the Sun's activity cycle, future observations should reveal changes in the preferred phases of spot-crossing anomalies.Comment: ApJ, in press [9 pages

Serviço de avaliação genética de reprodutores ovinos. S.A.G.R.O.: resultados de 1998.

Na ovinocultura tipo carne, a premência na busca de um produto com qualidade, em quantidade abundante no menor espaço de tempo possível, é uma realidade para aqueles produtores que desejarem abarcar uma fatia no mercado tão cobiçado da "proteína vermelha".bitstream/item/109844/1/SERVICO-DE-AVALIACAO-GENETICA.pd

A Study of the Shortest-Period Planets Found With Kepler

We present the results of a survey aimed at discovering and studying transiting planets with orbital periods shorter than one day (ultra--short-period, or USP, planets), using data from the {\em Kepler} spacecraft. We computed Fourier transforms of the photometric time series for all 200,000 target stars, and detected transit signals based on the presence of regularly spaced sharp peaks in the Fourier spectrum. We present a list of 106 USP candidates, of which 18 have not previously been described in the literature. In addition, among the objects we studied, there are 26 USP candidates that had been previously reported in the literature which do not pass our various tests. All 106 of our candidates have passed several standard tests to rule out false positives due to eclipsing stellar systems. A low false positive rate is also implied by the relatively high fraction of candidates for which more than one transiting planet signal was detected. By assuming these multi-transit candidates represent coplanar multi-planet systems, we are able to infer that the USP planets are typically accompanied by other planets with periods in the range 1-50 days, in contrast with hot Jupiters which very rarely have companions in that same period range. Another clear pattern is that almost all USP planets are smaller than 2 $R_\oplus$, possibly because gas giants in very tight orbits would lose their atmospheres by photoevaporation when subject to extremely strong stellar irradiation. Based on our survey statistics, USP planets exist around approximately $(0.51\pm 0.07)\%$ of G-dwarf stars, and $(0.83\pm 0.18)\%$ of K-dwarf stars.Comment: 20 pages, 10 figures. Submitted to ApJ. This version has been reviewed by a refere

The Transit Light Curve project. XIV. Confirmation of Anomalous Radii for the Exoplanets TrES-4b, HAT-P-3b, and WASP-12b

We present transit photometry of three exoplanets, TrES-4b, HAT-P-3b, and WASP-12b, allowing for refined estimates of the systems' parameters. TrES-4b and WASP-12b were confirmed to be "bloated" planets, with radii of 1.706 +/- 0.056 R_Jup and 1.736 +/- 0.092 R_Jup, respectively. These planets are too large to be explained with standard models of gas giant planets. In contrast, HAT-P-3b has a radius of 0.827 +/- 0.055 R_Jup, smaller than a pure hydrogen-helium planet and indicative of a highly metal-enriched composition. Analyses of the transit timings revealed no significant departures from strict periodicity. For TrES-4, our relatively recent observations allow for improvement in the orbital ephemerides, which is useful for planning future observations.Comment: AJ, in press [11 pages]; corrected error in distance to WASP-1

Towards spin injection from silicon into topological insulators: Schottky barrier between Si and Bi2Se3

A scheme is proposed to electrically measure the spin-momentum coupling in the topological insulator surface state by injection of spin polarized electrons from silicon. As a first approach, devices were fabricated consisting of thin (<100nm) exfoliated crystals of Bi2Se3 on n-type silicon with independent electrical contacts to silicon and Bi2Se3. Analysis of the temperature dependence of thermionic emission in reverse bias indicates a barrier height of 0.34 eV at the Si-Bi2Se3 interface. This robust Schottky barrier opens the possibility of novel device designs based on sub-band gap internal photoemission from Bi2Se3 into Si