Found 51 talks archived in Planetary systems
Our group is presently conducting an observational campaign, using the 10-meter Gran Telescopio Canarias (GTC), to obtain the transmission spectrum of several exoplanets during a transit event. The GTC instrument OSIRIS is used in its long-slit spectroscopic mode, covering the spectral range of 520-1040 nm, and observations are taken using a set of custom-built slits of various, broad, widths. We integrate the stellar ﬂux of both stars in different wavelength regions producing several light curves and ﬁt transit models in order to obtain the star-to-planet radius ratio Rp/Rs across wavelength. A Markov Chain Monte Carlo (MCMC) Bayesian approach is used for the transit fitting. With our instrumental setup, OSIRIS has been able to reach precisions down to 250 ppm (WASP-48b, V=11.06 mag) for each color light curve 10 nm wide, in a single transit. Central transit timing accuracies have been measured down to 6 seconds.
Here, we will present reﬁned planet parameters, the detection of planet color signatures, and the transmission spectrum of a set of know transiting exoplanets, namely: WASP-43b, HAT-P-32b, HAT-P-12b, WASP-48b. We will also discuss the capabilities and limitations of GTC with current and future instrumentation, and the role of GTC as tool for the follow up of faint Kepler targets. In particular, we will present the GTC observations of the intriguing evaporating planet KIC 12557548b, for which we performed simultaneous color light curves, and a search for alkali elements in its planetary tail. Other setups for observations (Broad and tunable filter photometry) have also been used and will be briefly discussed. The lessons learned from our GTC exoplanet observations will be discussed in the context of the E-ELT future capabilities.
The discovery of earth-like planets is nowadays the main goal of the entire exoplanets field. Despite the recent success of transiting programs, the measurement of radial velocities (RV) is still the most powerful method to find them. M-Dwarfs, given their low masses, and close-in habitable zone have become the perfect targets for the current generation of spectrographs. In this talk I will present our own M-Dwarfs RV program here at the IAC, explaining our methods, goals, difficulties and preliminary results.
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.
Traditionally, astronomers study stars and planets by telescope. But we can also learn about them by using a microscope – through studying meteorites. From meteorites, we can learn about the processes and materials that shaped the Solar System and our planet. Tiny grains within meteorites have come from other stars, giving information about the stellar neighbourhood in which the Sun was born.
Meteorites are fragments of ancient material, natural objects that survive their fall to Earth from space. Some are metallic, but most are made of stone. They are the oldest objects that we have for study. Almost all meteorites are fragments from asteroids, and were formed at the birth of the Solar System, approximately 4570 million years ago. They show a compositional variation that spans a whole range of planetary materials, from completely unmelted and unfractionated stony chondrites to highly fractionated and differentiated iron meteorites. Meteorites, and components within them, carry records of all stages of Solar System history. There are also meteorites from the Moon and from Mars that give us insights to how these bodies have formed and evolved.
In her lecture, Monica will describe how the microscope is another tool that can be employed to trace stellar and planetary processes.