Found 30 talks width keyword exoplanets
I will present the last results of the Transit Monitoring in the South (TraMoS) project. Since 2008, TraMoS has monitored transits of 30 exoplanets with telescopes located in Chile with the following goals: (1) to reﬁne the physical and/or orbital parameters of those exoplanet systems, and (2) to search for Transit Timing Variations (TTVs) and perturbations in other transit parameters, that could indicate the presence of additional bodies in the system. I will also discuss recent results and the scope of ongoing/future exoplanets projects at the IAC, in particular: transmission spectroscopy of selected exoplanets, secondary eclipse observations and dynamical simulations to validate/confirm exoplanets candidates.
The discovery of new planets beyond our solar system, in particular the detection and characterization of other habitable planets similar to the Earth, is a fascinating intellectual adventure. The completely unexpected characteristics of exoplanets are capturing the imagination and interest of the scientific community and the general public. More recently the large population of Super-Earth planet questions the universality of our Solar System as a typical planetary system. While the quest to find bodies similar to the Earth is still on going, the first spectra of exoplanets have been taken, signaling the shift from an era of discovery to one of physical and chemical characterization. This talk will provide an overview of current outcomes of planet programs as well as its limitation and prospects to move forward.
El pasado 6 de Junio de 2012 tuvo lugar el ultimo transito de Venus frente al Sol del siglo XXI, visible desde la Tierra. Los transitos de Venus han sido observados historicamente proporcionando informacion sobre del tamaño del Sol o la distancia Tierra-Sol. Hoy en dia, con la explosion del campo de exoplanetas, y la cada vez mas cercana deteccion de planeta potencialmente habitables, el transito de Venus ofrecia una oportunidad unica de medir el espectro de transmision de un planeta rocoso. Con esta intencion, en el IAC se diseño intrumentacion especifica y se realizo una expedicion a Australia, al tiempo que se observaba tambien desde telescopios en Chile. Este es un resumen de las peripecias personales, intrumentales y cientificas que suponen este tipo de retos, y que llevaron a la *posible* deteccion del dioxido de carbono en la atmosfera de Venus.
The CoRoT space mission aims at detecting planets with the transit method. In operation for more than 6 years, the instrument has monitored a couple of ten fields located in two opposite directions the Galactic plane for durations up to about 160 days. Transits are detected in about 100 up to 300 light curves per run. The large majority of them are however pinpointed as transiting stellar systems thanks to the identification of secondary eclipses or light curve modulation. The nature of the remaining candidates is then assessed through a multi-step strategy of complementary observations. This approach has allowed the discovery of a variety of planets with a large range of properties, from the first Super-Earth, CoRoT-7b to CoRoT-9b, the first temperate hot Jupiter or even the two transiting companions in the theoretical mass domain of brown dwarfs. We will review the status of the mission and then present the CoRoT exoplanetary systems and their properties.
Spectroscopic observations of stars do not only provide us with valuable information about the stars themselves, but over the last years such observations have lead to numerous exoplanet discoveries and new insights into planet formation. One important clue emerged at the dawn of the field: the existence of hot Jupiters, gas giants with orbital distances much smaller than an astronomical unit. We and other groups found some of these planets orbiting their stars on highly inclined or even retrograde orbits. I show how the orientation of the stellar axis in relation to the orbital plane (obliquity) reveals the mechanism by which these planets move inwards. Similar measurements in multiple transiting planet systems, with smaller planets will further enhance our understanding of the formation and evolution of planetary systems. In order to take those measurements we need to improve the way we analyze spectra. I present recent results obtained with such a new technique. These include multiple planet systems and results from my "BANANA" survey of close binaries, some of which, such as DI Herculis, also show strong misalignment. The same technique will allow for a reduction of stellar noise in radial velocity surveys, improving our ability to search for smaller, more Earth like planets around bright nearby stars.
Ultracool dwarfs represent the low-mass tail of the distribution of primary masses for which planets can be found with the Kepler satellite. Our team has identified 42 new ultracool dwarfs in the Kepler field of view that have started to be observed with this space telescope via its General Observer and Director Discretionary Time programs. First results of a study of Kepler light curves of 18 very low-mass dwarfs will be presented at this talk. It is demostrated that Kepler is sensitive to moon sized companions of ultracool dwarfs at short orbital periods (few days), and an intriguing candidate will be shown. Results from a ground-based infrared transit survey will also be presented which confirm the lack of Hot Jupiters around very low-mass primaries. Last but not least, a concept for a sustainable hybrid Hypertelescope that would be crucial to follow-up rocky planets will also be introduced.
So far more than 800 planets have been discovered and their
characterization is becoming more important. Transiting planets offer
the unique opportunity of detecting planetary atmospheres, helping to
improve the theoretical models of atmospheric composition under
different physical parameters (densities, irradiation, etc). However,
the precision needed to detect atoms and molecules, requires big
telescopes and stable instruments in order to obtain a good
signal-to-noise. In this talk I'll review the efforts, technical
challenges and current results that our group of Planets and Low Mass
stars is obtaining using GTC to study extra-solar planets.
CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Échelle Spectrographs) is a next-generation instrument being built for the 3.5m telescope at the Calar Alto Observatory by a consortium of German and Spanish institutions. It consists of two separated spectrographs covering the wavelength ranges from 0.5 to 1.0 mum and from 1.0 to 1.7 mum with spectral resolutions R = 82,000, each of which shall perform high-accuracy radial-velocity measurements (~1 m/s) with long-term stability. The fundamental science objective of CARMENES is to carry out a survey of ~300 late-type main-sequence stars with the goal of detecting low-mass planets in their habitable zones. We aim at being able to detect 2 MEarth planets in the habitable zone of M5V stars. The CARMENES first light is expected to occur in Spring 2014.
We review observations of a representative set of extrasolar planets that transit their stars, concentrating on those discovered and characterized by the XO Project. Spectra of these planets in transit and in eclipse have made significant contributions to our understanding of hot gas giant exoplanets, including 1) evidence for planet-planet scattering to transfer the planets from where they are formed to where we observe them, 2) hot stratospheres of these exoplanets, and two possible mechanisms to maintain them, and 3) water vapor detected in the near-IR spectrum of the exoplanet XO-1b in transit. For the latter case, we compare near-IR spectra obtained with two HST instruments: NICMOS and WFC3 with its new spatial scanning technique. We then present the spectrum of the super-Earth exoplanet GJ 1214b from the visible to the infrared, and focus on the definitive results obtained with HST WFC3 that show a featureless near-IR spectrum, indicative of either a large mean molecular weight in the planet's atmosphere, or obscuring haze (Berta et al. 2012). We identify similar observations that are being made with HST now, and will be made with JWST, and other telescopes in the future. We conclude by summarizing the Transiting Exoplanet Survey Satellite, TESS, which will discover the nearest, transiting rocky exoplanets, those most interesting and most suitable for follow-up characterization of the sort we have presented.
At the end of 2008, on ideas of teams from the Observatoire de la Côte d’Azur (OCA) and IAC, the CoRoT satellite observed the star HD 46375, known to host a non-transiting Saturn-mass exoplanet with a 3.023 day period. HD 46375 is the brightest star with a known close-in planet in the CoRoT accessible field of view. As such, it was targeted by the CoRoT additional program and observed in a CCD normally dedicated to the asteroseismology program, to obtain an ultra-precise photometric lightcurve and detect or place upper limits on the brightness of the planet. In addition, a ground-based support was simultaneously performed with the high-resolution NARVAL spectro-polarimeter to constrain the stellar atmospheric and magnetic properties. In this seminar, I will present the main results, in particular the stellar constrain we obtained thanks to the detection of the oscillation mode signature and the plausible detection of the planetary signal, which, if confirmed with future observations, would be the first detection of phase changes in the visible for a non-transiting planet.
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