A5045823971- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Atmospheric Ozone and Climate
- Astronomical Observations and Instrumentation
- Atmospheric and Environmental Gas Dynamics
- Planetary Science and Exploration
- Solar and Space Plasma Dynamics
- Calibration and Measurement Techniques
- Gamma-ray bursts and supernovae
- Spectroscopy and Laser Applications
- Meteorological Phenomena and Simulations
- Adaptive optics and wavefront sensing
- Isotope Analysis in Ecology
- Atmospheric aerosols and clouds
- Space Exploration and Technology
- Astrophysical Phenomena and Observations
- Spacecraft Design and Technology
- Cryospheric studies and observations
- Image Processing Techniques and Applications
- History and Developments in Astronomy
- High-pressure geophysics and materials
- Image and Signal Denoising Methods
- Gas Sensing Nanomaterials and Sensors
University of Chile
2015-2024
Cerro Tololo Inter-American Observatory
2003-2016
Cornell University
2003-2014
Institut de Planétologie et d'Astrophysique de Grenoble
2013
Centre National de la Recherche Scientifique
2013
Fundación Chile
2010
University of Hertfordshire
2009
U.S. National Science Foundation
2003
Association of Universities For Research In Astronomy
2003
Hospital Universitario de La Princesa
2000-2002
An exoplanet extracted from the bright Direct imaging of Jupiter-like exoplanets around young stars provides a glimpse into how our solar system formed. The brightness requires use next-generation devices such as Gemini Planet Imager (GPI). Using GPI, Macintosh et al. discovered planet orbiting star, 51 Eridani (see Perspective by Mawet). planet, Eri b, has methane signature and is probably smallest that been directly imaged. These findings open door to understanding origins herald dawn new...
We present the discovery of a Neptune-mass planet OGLE-2007-BLG-368Lb with planet–star mass ratio q = [9.5 ± 2.1] × 10−5 via gravitational microlensing. The planetary deviation was detected in real-time thanks to high cadence Microlensing Observations Astrophysics survey, light-curve monitoring and intensive follow-up observations. A Bayesian analysis returns stellar distance at Ml 0.64+0.21−0.26 M☉ Dl 5.9+0.9−1.4 kpc, respectively, so separation are Mp 20+7−8 M⊕ 3.3+1.4−0.8 AU,...
We present a library of near-infrared (1.1-2.45 microns) medium-resolution (R~1500-2000) integral field spectra 15 young M6-L0 dwarfs, composed companions with known ages and isolated objects. use it to (re)derive the NIR spectral types, luminosities physical parameters targets, test (BT-SETTL, DRIFT-PHOENIX) atmospheric models. derive infrared types L0+-1, M9.5+-0.5, M9.25+-0.25, M8+0.5-0.75, M8.5+-0.5 for AB Pic b, Cha J110913-773444, USco CTIO 108B, GSC 08047-00232 B, DH Tau CT HR7329B,...
In this work we present chromospheric activity indices, kinematics, radial-velocities and rotational velocities for more than 850 FGK-type dwarfs subgiant stars in the southern hemisphere test how best to calibrate measure S-indices from echelle spectra. We confirm bimodal distribution of activities such highlight role that active K-dwarfs play biasing number stars. show age-activity relationship does appear continue ages older Sun if simply compare main sequence stars, with an offset around...
Context. Planetary companions of a fixed mass induce larger amplitude reflex motions around lower-mass stars, which helps make M dwarfs excellent targets for extra-solar planet searches. State the art velocimeters with $\sim$1m/s stability can detect very low-mass planets out to habitable zone these stars. Low-mass, small, are abundant dwarfs, and most known potentially orbit one cool Aims. Our M-dwarf radial velocity monitoring HARPS on ESO 3.6m telescope at La Silla observatory makes major...
Context: Since the first exoplanetary atmosphere detection using Hubble Space Telescope, characterization of exoplanet atmospheres from ground have been playing an increasingly important role in analysis such thanks to enhancement telluric correction techniques. At present, several species discovered HD 209458b, all them consistent with theoretical models. Aims: Data acquired High Dispersion Spectrograph on Subaru telescope are re-analysed. We expect discover new 209458b. In addition shed...
We report nine new transit epochs of the extrasolar planet WASP-5b, observed in Bessell I band with Southern Astrophysical Research Telescope at Cerro Pachon Observatory and SMARTS 1 m Tololo Inter-American Observatory, between 2008 August 2009 October. The transits have been combined all previously published data for this to provide a Transit Timing Variation (TTV) analysis its orbit. find no evidence TTV rms variations larger than minute over 3 year time span. This result discards presence...
Context: More than 50 exoplanets have been found around giant stars, revealing different properties when compared to planets orbiting solar-type stars. In particular, they are Super-Jupiters and not interior $\sim$ 0.5 AU. Aims: We conducting a radial velocity study of sample 166 stars aimed at studying the population close-in how their orbital physical influenced by post-MS evolution host star. Methods: collected multi epochs spectra for all targets in our sample. computed precision...
We report the discovery of eight new giant planets, and updated orbits for four known orbiting dwarf subgiant stars using CORALIE, HARPS, MIKE instruments as part Calan-Hertfordshire Extrasolar Planet Search. The planets have masses in range 1.1-5.4MJs, orbital periods from 40-2900 days, eccentricities 0.0-0.6. They include a double-planet system most massive star our sample (HD147873), two eccentric (HD128356b HD154672b), rare 14 Herculis analogue (HD224538b). highlight some population...
We report the discovery of two additional planetary companions to WASP-41 and WASP-47. c is a planet minimum mass 3.18 $\pm$ 0.20 M$_{\rm Jup}$ eccentricity 0.29 0.02, it orbits in 421 2 days. WASP-47 1.24 0.22 0.13 0.10, 572 7 Unlike most systems that include hot Jupiter, these with Jupiter have long-period located at only $\sim$1 au from their host star. rather young star known be chromospherically active. To differentiate its magnetic cycle radial velocity effect induced by second planet,...
We present radial velocity measurements of a sample M5V-M9V stars from our Red-Optical Planet Survey, ROPS, operating at 0.65-1.025 micron. Radial velocities for 15 stars, with r.m.s. precision down to 2.5 m/s over week long time scale are achieved using Thorium-Argon reference spectra. sensitive planets m_psin(i) >= 1.5 MEarth (3 2-sigma) in the classical habitable zone and observations currently rule out > 0.5 MJup 0.03 AU all targets. A total 9 targets exhibit < 16 m/s, which enables us...
Abstract We present the open-source Bayesian Atmospheric Radiative Transfer (BART) retrieval package, which produces estimates and uncertainties for an atmosphere’s thermal profile chemical abundances from observations. Several BART components are also stand-alone packages, including parallel Multi-Core Markov-chain Monte Carlo (MC3), implements several samplers; a line-by-line radiative-transfer model, transit ; code that calculates Thermochemical Equilibrium Abundances (TEA), test suite...
We report the discovery of a brown dwarf on an eccentric orbit and with semimajor axis that places it in desert region around star HD191760. The has spectral type G3IV/V metallicity ([Fe/H]) 0.29 dex. HD191760 adds to small number metal-rich stars companions. (HD191760b) is found have orbital period 505.57+/-0.40 days 1.35+/-0.01 AU, placing firmly desert. eccentricity HD191760b be 0.63+/-0.01, meaning reaches as close 0.5 AU from host star. Dynamical simulations indicate no inner planets...
We announce the discovery of a low-mass planet orbiting super metal-rich K0V star HD77338 as part our on-going Calan-Hertfordshire Extrasolar Planet Search. The best fit solution has an orbital period 5.7361\pm0.0015 days and with radial velocity semi-amplitude only 5.96\pm1.74 m/s, we find minimum mass 15.9+4.7-5.3 Me. eccentricity from this is 0.09+0.25-0.09, agreement for data set using Bayesian analysis periodogram analysis. measure metallicity +0.35\pm0.06 dex, whereas another recent...
Context: To date, more than 30 planets have been discovered around giant stars, but only one of them has found to be orbiting within 0.6 AU from the host star, in direct contrast what is observed for FGK dwarfs. This result suggests that evolved stars destroy/engulf close-in during red phase. Aims: We are conducting a radial velocity survey 164 bright G and K southern hemisphere with aim studying effect star evolution on inner structure planetary systems. In this paper we present...
We discover that the very low-mass brown dwarf OTS44 (M9.5, ~12 M_Jup) has significant accretion and a substantial disk, which demonstrates processes accompany canonical star formation occur down to central mass of few Jupiter masses. in VLT/SINFONI spectra strong, broad, variable Paschen beta emission is evidence for active at planetary border. also detect strong Halpha literature spectrum determine an EW (-141 A) indicative accretion. Both Pa lines have broad profiles with wings extending...
CONTEXT. Exoplanet searches have demonstrated that giant planets are preferentially found around metal-rich stars and their fraction increases with the stellar mass. AIMS. During past six years, we conducted a radial velocity follow-up program of 166 stars, to detect substellar companions, characterizing orbital properties. Using this information, aim study role evolution in parameters unveil possible correlations between properties occurrence rate planets. METHODS. FEROS CHIRON spectra,...
Chauvin et al. 2005 imaged a co-moving companion at ~260 AU from the young star AB Pic A. Evolutionary models predictions based on J H K photometry of b suggested mass ~13 - 14 MJup, placing object deuterium-burning boundary. We used adaptive-optics-fed integral field spectrograph SINFONI to obtain high quality medium-resolution spectra (R = 1500-2000) over 1.1 2.5 microns range. Our analysis relies comparison our standard templates and latest libraries synthetic developed by Lyon's Group....
We present the first results from our Red Optical Planet Survey (ROPS) to search for low mass planets orbiting late type dwarfs (M5.5V - M9V) in their habitable zones (HZ). Our observations, with red arm of MIKE spectrograph (0.5 0.9 microns) at 6.5 m Magellan Clay telescope Las Campanas Observatory indicate that >= 92 per cent flux lies beyond 0.7 microns. use a novel approach is essentially hybrid simultaneous iodine and ThAr methods determining precision radial velocities. apply least...
We report 12 new transit observations of the exoplanet WASP-4b from Transit Monitoring in South (TraMoS) project. These transits are combined with all previously published data for this planet to provide an improved radius measurement Rp = 1.395 ± 0.022Rjup and ephemerides. In a homogeneous analysis search timing variations (TTVs) we find no evidence those rms amplitudes larger than 20 s over 4-yr time span. This lack TTVs rules out presence additional planets system masses about 2.5, 2.0...
We obtained medium-resolution near-infrared spectra of seven young M9.5-L3 dwarfs classified in the optical. aim to confirm low surface gravity objects NIR. also test whether atmospheric models correctly represent formation and settling dust clouds atmosphere late-M L dwarfs. used ISAAC at VLT obtain targets. compared them those mature BD, late-type companions nearby stars with known ages, order identify study gravity-sensitive features. computed spectral indices weakly sensitive derive...
Context: So far more than 60 substellar companions have been discovered around giant stars. These systems present physical and orbital properties that contrast to those detected orbiting less evolved Aims: We are conducting a radial velocity survey of 166 bright stars in the southern hemisphere. The main goals our project detect characterize planets close-in orbits order study effects host star evolution on their properties. Methods: obtained precision velocities for HIP67851 HIP97233...
The proliferation of exoplanet discoveries, particularly within such exotic environments as the Neptune desert, challenges our understanding planetary atmospheres undergoing intense irradiation. unexpected discovery an ultra-hot deep this desert offers a prime opportunity for in-depth atmospheric studies. This research builds upon previous observations LTT9779b from space-based telescopes, including Transiting Exoplanet Survey Satellite (TESS), Spitzer Space Telescope, and CHaracterising...