Found 33 talks width keyword exoplanets
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.
I present a general overview of the PLAnetary Transits and Oscillations of stars (PLATO) space mission. PLATO was approved by ESA’s Science Programme Committee, together with Euclid and Solar Orbiter missions, to enter the so-called definition phase, i.e. the step required before the final decision is taken (only two missions will be implemented). To be launched in 2018, PLATO is a third generation mission, which will take advantage of the scientific return from the currently flying space missions CoRoT (CNES, ESA, launched in 2006), and Kepler (NASA, launched in 2009). Moreover, the preparation and exploitation of the missions will benefit from the GAIA (ESA) mission data, together with new generation ground-based instrumentation like North-HARPS, GIANO, CARMENES, etc. Finally, I summarize the current organization status of the mission,focusing on the Spanish role within the consortium.
AbstractThe RV method is responsible for discovering the majority of planets that orbit stars other than our Sun. However, one problem with this technique is that stellar jitter can cause RV variations that mimic or mask out a planet signature. There have been several instances in the past when stars have shown periodic RV variations which are firstly attributed to a planet and later found to be due to stellar spots, e.g. BD+20 1790 (Figueira, P et al. 2010) and CJ674 (Turnball et al. 204). So far the method of choice to overcome these problems is to avoid observing stars which show levels of high activity. However, this does not solve the problem: it merely avoids it. We have therefore been developing a code which separates out stellar jitter from the RVs to enable active planets to be looked at for planets. I will talk about our technique as well as show some exciting preliminary results.
AbstractThe main goal of the MASTER-Net project is to produce a unique fast sky survey with all sky observed over a single night down to a limiting magnitude of 21. Such a survey will make it possible to address a number of fundamental problems: search for dark energy via the discovery and photometry of supernovae (including SNIa), search for exoplanets, microlensing effects, discovery of minor bodies in the Solar System, and space-junk monitoring. All MASTER telescopes can be guided by alerts, and we plan to observe prompt optical emission from gamma-ray bursts synchronously in several filters and in several polarization planes.
Among the over 450 known exoplanets, the planets that transit their central star stand out, due to the wealth of information that can be gained about both planet and central star. The CoRoT mission has been designed to detect smaller and longer-periodic transiting exoplanets than can be found from ground observations. CoRoT-9b was detected by the satellite in summer 2008 and underwent follow-up observations from ground for another year. It stands out as having the largest periastron distance of all transiting planets, being expected to maintain permanently a moderate surface temperature, estimated between 250 and 430K. It is also the first exoplanet to which planet evolution models can be applied, without uncertain corrections that have been needed for 'hot' transiting planets. These models indicate it to be rather similar to Jupiter. Temperate gas-giant planets with low-to-moderate eccentric orbits constitute the largest group of currently known planets; they are probably similar to the gas giants of the solar system. With CoRoT-9b being this group’s first transiting planet, it may give rise to a much better understanding of these common planets. While CoRoT-9b itself is certainly not habitable, moons around it could be similar to Titan and provide some chance of habitability. Upcoming observations with the Spitzer space telescope are designed to improve on planet parameters and to perform a deeper search for the detection of its moons.
Up to now more than 400 extrasolar planets have been discovered, about 60 of them are transiting. Transiting extra-solar planets are particularly interesting, because their masses, diameters, densities and orientations of their orbits can be determined. Observations with the CoRoT Satellite have now turned up 10 transiting extrasolar planets. Although most of them are gas giants, it turns out that each of them is very special, and many of them have surprising properties. An unexpected discovery was for example the detection of emission lines from CoRoT 1b. Other interesting discoveries are CoRoT 2b, a planet orbiting a young star, and CoRoT 3b the first transiting brown dwarf orbiting a main sequence star. While the detection of transiting gas giants is interesting, the ultimate goal of CoRoT clearly was the detection of rocky planets. CoRoT has detected a solar-like star which shows transits that are only 0.03% deep. In this talk it it is demonstrated that this planet is in fact the first planet found outside our solar system from which we can firmly say that it is a rocky planet. New observations of this interesting object even constrain the properties of its exosphere.
AbstractThe surface abundance of lithium on the Sun is 140 times less than protosolar, yet the temperature at the base of the surface convective zone is not hot enough to burn Li. A large range of Li abundances in solar type stars of the same age, mass and metallicity is observed, but theoretically difficult to understand. An earlier suggestion that Li is more depleted in stars with planets was weakened by the lack of a proper comparison sample of stars without detected planets. Here we report Li abundances for an unbiased sample of solar-analogue stars with and without detected planets. We find that the planet-bearing stars have less than 1 per cent of the primordial Li abundance, while about 50 per cent of the solar analogues without detected planets have on average 10 times more Li. The presence of planets may increase the amount of mixing and deepen the convective zone to such an extent that the Li can be burned. We also present Be abundances for a sample of stars with and without known planets and discuss the possible relation of these light element with the presence of planetary systems.
AbstractThe 3.8m optical and infrared telescope, which is Japan's first segmented mirror telescope, is now being constructed using the world's first super high precision, high speed grinding technology and the world's first truss structure drive system. This is the joint project between Kyoto University, Nagoya University, National Astronomical Observatory, and Nano-Optonics Energy (private company) with the budget of the Nnao-Optonics Energy and Dr Hiroshi Fujiwara (CEO of the Nano-Optonics Energy). The telescope will be completed in 2012 and installed in Okayama, and will become the biggest optical and infrared telescope in east Asia. The technologies for making this telescope such as (1) grinding technology, (2) segmented mirror, and (3) truss structure drive system are also basic technologies for the future extremely large telescope such as the 30m telescope. The scientific objective of the telescope is the search for the transient objects (gamma ray bursts, black hole binaries, stellar flares) and the extra solar planets. How this project has emerged and developed will be discussed in detail, including also the discussion about the possible future international collaboration.
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