The distance to the Andromeda Galaxy from eclipsing binaries (2009)
Vilardell, F., Ribas, I., Jordi, C., Fitzpatrick, E. L., Guinan, E. F.
The cosmic distance scale largely depends on distance determinations to Local Group galaxies. In this sense, the Andromeda Galaxy (M31) is a key rung to better constrain the cosmic distance ladder. A...
Beaulieu, J. P., Kipping, D. M., Batista, V., Tinetti, G., Ribas, I., Carey, S., ...
The hot Jupiter HD 209458b was observed during primary transit at 3.6, 4.5, 5.8 and 8.0 microns using the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. We detail here the procedures we...
The asteroseismic ground-based observational counterpart of CoRoT (2009)
Uytterhoeven, K., Poretti, E., Mathias, P., Amado, P. J., Rainer, M., Martin-Ruiz, S., ...
We present different aspects of the ground-based observational counterpart of the CoRoT satellite mission. We give an overview of the selected asteroseismic targets, the numerous instruments and...
Kaltenegger, L., Eiroa, C., Ribas, I., Paresce, F., Leitzinger, M., Odert, P., ...
In this paper we present and discuss the criteria for selecting potential target stars suitable for the search for Earth like planets, with a special emphasis on the stellar aspects of habitability....
Fully Automated Approaches to Analyze Large-Scale Astronomy Survey Data (2009)
Prsa, A., Guinan, E. F., Devinney, E. J., Engle, S. G., DeGeorge, M., McCook, G. P., ...
Observational astronomy has changed drastically in the last decade: manually driven target-by-target instruments have been replaced by fully automated robotic telescopes. Data acquisition methods...
Absolute properties of the low-mass eclipsing binary CM Draconis (2008)
Morales, J. C., Ribas, I., Jordi, C., Torres, G., Gallardo, J., Guinan, E. F., ...
Spectroscopic and eclipsing binary systems offer the best means for determining accurate physical properties of stars, including their masses and radii. The data available for low-mass stars have...
Towards A Census of Earth-mass Exo-planets with Gravitational Microlensing (2008)
Beaulieu, J. P., Kerins, E., Mao, S., Bennett, D., Cassan, A., Dieters, S., ...
Thirteen exo-planets have been discovered using the gravitational microlensing technique (out of which 7 have been published). These planets already demonstrate that super-Earths (with mass up to ~10...
Font-Ribera, A., Miralda-Escudé, J., Ribas, I.
A new model for the formation of Jovian planets is proposed. We consider planets forming at large distances from a protostar (>100 AU) through direct fragmentation of a gas cloud, by the same...
Primary transit of the planet HD 189733b at 3.6 and 5.8 µm (2008)
Beaulieu, J. P., Carey, S., Ribas, I, Tinetti, G.
The hot Jupiter HD 189733b was observed during its primary transit using the Infrared Array Camera on the Spitzer Space Telescope. The transit depths were measured simultaneously at 3.6 and 5.8 μm....
Catalan, S., Isern, J., Garcia-Berro, E., Ribas, I.
The initial-final mass relationship connects the mass of a white dwarf with the mass of its progenitor in the main-sequence. Although this function is of fundamental importance to several fields in...
Nucleosynthesis in stellar flares (2008)
Nuclear interactions of ions accelerated at the surface of flaring stars can produce fresh isotopes in stellar atmospheres. Although this nucleosynthesis is not significant for the chemical evolution...
Fundamental properties of low-mass stars (2007)
Ribas, I., Morales, J., Jordi, C., Baraffe, I., Chabrier, G., Gallardo, J.
Numerous investigations on the fundamental properties of low-mass stars using eclipsing binaries indicate a strong discrepancy between theory and observations that is still awaiting explanation....
The effect of activity on stellar temperatures and radii (2007)
Morales, J. C., Ribas, I., Jordi, C.
Recent analyses of low-mass eclipsing binary stars have unveiled a significant disagreement between the observations and the predictions of stellar structure models. Results show that theoretical...
H. Lammer, F. Selsis, I. Ribas, E. F. Guinan, S. J. Bauer, W. W. Weiss
Past studies addressing thermal atmospheric escape of hydrogen from “Hot Jupiters ” have been based on the planet’s effective temperature, which, as we show here, is not physically relevant for...
Primary transit of the planet HD189733b at 3.6 and 5.8 microns (2007)
Beaulieu, J. P., Carey, S., Ribas, I., Tinetti, G.
The hot Jupiter HD 189733b was observed during its primary transit using the Infrared Array Camera on the Spitzer Space Telescope. The transit depths were measured simultaneously at 3.6 and 5.8...
Optical flares from the faint mid-dM star 2MASS J00453911+4140396 (2007)
Kővári, Zs., Vilardell, F., Ribas, I., Vida, K., Jordi, C., ...
We present $B$ and $V$ light curves of a large stellar flare obtained with the Wide Field Camera at the Isaac Newton 2.5-m telescope (La Palma). The source object is a faint ($m_V=21.38$) foreground...
Habitable planets around the star Gl 581? (2007)
Selsis, Franck, F. Kasting, J., Levrard, B., Paillet, J., Ribas, I., Delfosse, X.
Radial velocity surveys are now able to detect terrestrial planets at habitable distance from M-type stars. Recently, two planets with minimum masses below 10 Earth masses were reported in a triple...
Habitable planets around the star Gl 581? (2007)
Selsis, Franck, F. Kasting, J., Levrard, B., Paillet, J., Ribas, I., Delfosse, X.
Radial velocity surveys are now able to detect terrestrial planets at habitable distance from M-type stars. Recently, two planets with minimum masses below 10 Earth masses were reported in a triple...
Habitable planets around the star Gl 581? (2007)
Selsis, Franck, Kasting, J. F., Levrard, B., Paillet, J., Ribas, I., Delfosse, X.
Radial velocity surveys are now able to detect terrestrial planets at habitable distance from M-type stars. Recently, two planets with minimum masses below 10 Earth masses were reported in a triple...
WD0433+270: an old Hyades stream member or an Fe-core white dwarf? (2007)
Catalan, S., Ribas, I., Isern, J., Garcia-Berro, E.
G39-27/289 is a common proper motion pair formed by a white dwarf (WD0433+270) and a main-sequence star (BD+26 730) that apparently has been classified as a member of the Hyades open cluster....
The initial-final mass relationship from white dwarfs in common proper motion pairs (2007)
Catalan, S., Isern, J., Garcia-Berro, E., Ribas, I., Prieto, C. Allende, Bonanos, A. Z.
The initial-final mass relationship of white dwarfs, which is poorly constrained, is of paramount importance for different aspects in modern astrophysics. From an observational perspective, most of...
Vilardell, F., Jordi, C., Ribas, I.
Extragalactic Cepheids are the basic rungs of the cosmic distance scale. They are excellent standard candles, although their luminosities and corresponding distance estimates can be affected by the...
Water vapour in the atmosphere of a transiting extrasolar planet (2007)
Tinetti, G., Vidal-Madjar, A., Yung, Y., Carey, S., ...
Water is predicted to be among the most abundant (if not the most abundant) molecular species after hydrogen in the atmospheres of close-in extrasolar giant planets ('hot Jupiters'). Several attempts...
L'Observatori Astronòmic del Montsec (2007)
David Fernández, J. Colomé, I. Ribas, Jordi Isern Vilaboy, X. Palau
Habitable planets around the star Gl 581? (2007)
Selsis, Franck, F. Kasting, J., Levrard, B., Paillet, J., Ribas, I., Delfosse, X.
Radial velocity surveys are now able to detect terrestrial planets at habitable distance from M-type stars. Recently, two planets with minimum masses below 10 Earth masses were reported in a triple...
Habitable planets around the star Gl 581? (2007)
Selsis, Franck, F. Kasting, J., Levrard, B., Paillet, J., Ribas, I., Delfosse, X.
Radial velocity surveys are now able to detect terrestrial planets at habitable distance from M-type stars. Recently, two planets with minimum masses below 10 Earth masses were reported in a triple...
A project to determine an accurate distance to M31 using eclipsing binaries as standard candles
Eclipsing binaries suitable for distance determination in the Andromeda galaxy (2006)
Vilardell, F., Ribas, I., Jordi, C.
The Local Group galaxies constitute a fundamental step in the definition of cosmic distance scale. Therefore, obtaining accurate distance determinations to the galaxies in the Local Group, and...
Catalán, S., Ribas, I., Isern Villaboy, Jordi, Allende Prieto, C.
We have studied white dwarfs in common proper motion pairs (CPMPs) to improve the semi-empirical initial–final mass relationship of white dwarfs. In this contribution, we re- port new results...
Catalán, S., Ribas, I., Isern Villaboy, Jordi, Allende Prieto, C.
We have studied white dwarfs in common proper motion pairs (CPMPs) to improvethe semi-empirical initial–final mass relationship of white dwarfs. In this contribution, we re-port new results...
Catalán, S., Ribas, I., Isern Villaboy, Jordi, Allende Prieto, C.
We have studied white dwarfs in common proper motion pairs (CPMPs) to improve the semi-empirical initial–final mass relationship of white dwarfs. In this contribution, we re- port new results...
Effective temperature scale and bolometric corrections from 2MASS photometry (2006)
Masana, E., Jordi, C., Ribas, I.
This paper presents a method to determine effective temperatures, angular semi-diameters and bolometric corrections for population I and II FGK type stars based on V and 2MASS IR photometry. Accurate...
L'Observatori Astronòmic del Montsec (2006)
David Fernàndez, J. Colomí, I. Ribas, Jordi Isern Vilaboy, X. Palau
L'Observatori Astronòmic del Montsec (2006)
David Fernàndez, J. Colomí, I. Ribas, Jordi Isern Vilaboy, X. Palau
A possible black hole in the gamma-ray microquasar LS 5039 (2005)
Casares, J., Ribo, M., Ribas, I., Paredes, J. M., Marti, J., Herrero, A.
The population of high energy and very high energy gamma-ray sources, detected with EGRET and the new generation of ground-based Cherenkov telescopes, conforms a reduced but physically important...
GU Boo: A New 0.6 Msun Detached Eclipsing Binary (2005)
We have found a new low-mass, double-lined, detached eclipsing binary, GU Boo, among a sample of new variables from the ROTSE-I database. The binary has an orbital period of 0.488728 +/- 0.000002...
Orbital Parameters of the Microquasar LSI +61 303 (2005)
Casares, J., Ribas, I., Paredes, J. M., Marti, J., Prieto, C. Allende
New optical spectroscopy of the HMXB microquasar LSI +61 303 is presented. Eccentric orbital fits to our radial velocity measurements yield updated orbital parameters in good agreement with previous...
Ribas, I., Guinan, E. F., Guedel, M., Audard, M.
We report on the results of the Sun in Time multi-wavelength program (X-rays to the UV) of solar analogs with ages covering ~0.1-7 Gyr. The chief science goals are to study the solar magnetic dynamo...
Effective temperatures and radii of planet-hosting stars from IR photometry (2003)
Ribas, I., Solano, E., Masana, E., Gimenez, A.
In this paper we present and analyse determinations of effective temperatures of planet-hosting stars using infrared (IR) photometry. One of our goals is the comparison with spectroscopic...
Fundamental Properties and Distances of LMC Eclipsing Binaries: IV. HV 5936 (2003)
Fitzpatrick, E. L., Ribas, I., Guinan, E. F., Maloney, F. P., Claret, A.
We have determined the fundamental properties and distance of a fourth eclipsing binary system (EB) in the Large Magellanic Cloud, HV5936 (B0.5 V + B2 III). As in our previous studies, we combine...
The field brown dwarf LP 944-20 and the Castor moving group (2003)
A reliable age estimation for the field brown dwarf LP 944-20 is accomplished through the analysis of its kinematic properties. The space velocities of this star strongly suggest its membership in...
Photometric observations in the R and I bands of the detached M-type double-lined eclipsing binary CU Cnc have been acquired and analysed. The photometric elements obtained from the analysis of the...
Sanchis Gimeno, J. A., Alonso, L., Ribas, I., Asensio, I., Martínez Soriano, F.
Purpose of this work was to determine the differences in ocular axial length measurements carried out by one investigator using optical and ultrasound biometry on the same eye. In a prospective...
Ribas, I., Asensio, I., Martínez Soriano, Francisco, Alonso, L., Sanchis-Gimeno, J.A.
Purpose of this work was to determine the differences in ocular axial length measurements carried out by one investigator using optical and ultrasound biometry on the same eye. In a prospective...
A Systematic Spectroscopic X-Ray Study of Stellar Coronae with XMM-Newton: Early Results (2001)
Guedel, M., Audard, M., Smith, K. W., Sres, A., Escoda, C., Wehrli, R., ...
We have been conducting a comprehensive survey of stellar coronae with the XMM-Newton Reflection Grating Spectrometers during the commissioning, calibration, verification, and guaranteed time phases...
Fundamental Properties and Distances of LMC Eclipsing Binaries II. HV 982 (2000)
Fitzpatrick, E. L., Ribas, I., Guinan, E. F., DeWarf, L. E., Maloney, F. P., Massa, D.
We have determined the distance to a second eclipsing binary system (EB) in the Large Magellanic Cloud, HV982 (~B1 IV-V + ~B1 IV-V). The measurement of the distance -- among other properties of the...
The Distance to the Large Magellanic Cloud from the Eclipsing Binary HV2274 (1998)
Guinan, E. F., Fitzpatrick, E. L., DeWarf, L. E., Maloney, F. P., Maurone, P. A., Ribas, I., ...
The distance to the Large Magellanic Cloud (LMC) is crucial for the calibration of the Cosmic Distance Scale. We derive a distance to the LMC based on an analysis of ground-based photometry and...
. The aim of this study is to construct biparametric calibrations to estimate masses, radii and surface gravities for mainsequence stars using a photometric index related to effective temperature and...
Photometric versus Empirical Surface Gravities of Eclipsing Binaries (1997)
C. Jordi, I. Ribas, J. Torra, A. Giménez
. Systematic differences in photometric stellar surface gravity determination are studied by means of the comparison with empirical values derived from detached double-lined eclipsing binaries....
Effective Temperature Determination Of Eclipsing Binaries
C. Jordi, I. Ribas, A. Giménez, J. Torra, E. Oblak
Effective temperatures and distances of eclipsing binaries computed through Hipparcos trigonometric parallaxes were compared with the photometric determinations. The former were based on the radius,...