On the mass of the neutron star in Cyg X-2 (2009)
Casares, J., Hernandez, J. I. Gonzalez, Israelian, G., Rebolo, R.
We present new high resolution spectroscopy of the low mass X-ray binary Cyg X-2 which enables us to refine the orbital solution and rotational broadening of the donor star. In contrast with Elebert...
A homogeneous spectroscopic analysis of host stars of transiting planets (2009)
Eiff, M. Ammler-von, Santos, N. C., Sousa, S. G., Fernandes, J., Guillot, T., Israelian, G., ...
The analysis of transiting extra-solar planets provides an enormous amount of information about the formation and evolution of planetary systems. A precise knowledge of the host stars is necessary to...
Neves, V., Santos, N. C., Sousa, S. G., Correia, A. C. M., Israelian, G.
We present a uniform study of the chemical abundances of 12 elements (Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Na, Mg, and Al) derived from the spectra of 451 stars observed as part of one of the HARPS GTO...
Sousa, S. G., Santos, N. C., Mayor, M., Udry, S., Casagrande, L., Israelian, G., ...
To understand the formation and evolution of solar-type stars in the solar neighborhood, we need to measure their stellar parameters to high accuracy. We present a catalogue of accurate stellar...
Liske, J., Pasquini, L., Bonifacio, P., Bouchy, F., Carswell, R. F., Cristiani, S., ...
CODEX and ESPRESSO are concepts for ultra-stable, high-resolution spectrographs at the E-ELT and VLT, respectively. Both instruments are well motivated by distinct sets of science drivers. However,...
The CODEX-ESPRESSO experiment: cosmic dynamics, fundamental physics, planets and much more.. (2007)
Cristiani, S., Avila, G., Bonifacio, P., Bouchy, F., Carswell, B., D'Odorico, S., ...
CODEX, a high resolution, super-stable spectrograph to be fed by the E-ELT, the most powerful telescope ever conceived, will for the first time provide the possibility of directly measuring the...
The Black Hole Binary Nova Scorpii 1994 (GRO J1655-40): An improved chemical analysis (2007)
Hernandez, J. I. Gonzalez, Rebolo, R., Israelian, G.
The chemical analysis of secondary stars of low mass X-ray binaries provides an opportunity to study the formation processes of compact objects, either black holes or neutron stars. Following the...
Sousa, S. G., Santos, N. C., Israelian, G., Mayor, M.
We present a new automatic code (ARES) for determining equivalent widths of the absorption lines present in stellar spectra. We also describe its use for determining fundamental spectroscopic stellar...
The CODEX-ESPRESSO experiment: cosmic dynamics, fundamental physics, planets and much more (2007)
Cristiani, Stefano, Avila, Gerardo, Bonifacio, Piercarlo, Bouchy, Francois, Carswell, B., D'Odorico, Sandro D., ...
CODEX, a high-resolution, super-stable spectrograph to be fed by the E-ELT, the most powerful telescope ever conceived, will for the first time provide the possibility of directly measuring the...
The CODEX-ESPRESSO experiment: cosmic dynamics, fundamental physics, planets and much more (2007)
Cristiani, Stefano, Avila, Gerardo, Bonifacio, Piercarlo, Bouchy, Francois, Carswell, B., D'Odorico, Sandro D., ...
CODEX, a high-resolution, super-stable spectrograph to be fed by the E-ELT, the most powerful telescope ever conceived, will for the first time provide the possibility of directly measuring the...
On the Age of Stars Harboring Transiting Planets (2006)
Melo, C., Santos, N. C., Pont, F., Guillot, T., Israelian, G., Mayor, M., ...
Results of photometric surveys have brought to light the existence of a population of giant planets orbiting their host stars even closer than the hot Jupiters (HJ), with orbital periods below 3...
Ecuvillon, A., Israelian, G., Pont, F., Santos, N. C., Mayor, M.
We present a detailed study on the kinematics of metal-rich stars with and without planets, and their relation with the Hyades, Sirius and Hercules dynamical streams in the solar neighbourhood....
Santos, N. C., Ecuvillon, A., Israelian, G., Mayor, M., Melo, C., Queloz, D., ...
We used the UVES spectrograph (VLT-UT2 telescope) to obtain high-resolution spectra of 6 stars hosting transiting planets, namely for OGLE-TR-10, 56, 111, 113, 132 and TrES-1. The spectra are now...
Santos, N. C, Pont, F., Melo, C., Israelian, G., Bouchy, F., Mayor, M., ...
Context: During the past years photometric surveys, later complemented by follow-up radial-velocity measurements, have revealed the presence of several new extra-solar transiting planets, in very...
Santos, N. C, Pont, F., Melo, C., Israelian, G., Bouchy, F., Mayor, M., ...
Context: During the past years photometric surveys, later complemented by follow-up radial-velocity measurements, have revealed the presence of several new extra-solar transiting planets, in very...
Revised parameters for OGLE-TR-10 from UVES spectra: updated planetary physical properties (2006)
Mayor, M., Moutou, C., Coutenis, A., Pons, F., Melo, C., ...
We have obtained high-resolution UVES spectra with S/N>100 to accurately characterize the stellar parameters for the transiting planet-hosting star OGLE-TR-10. The obtained values were used to...
Santos, N. C, Pont, F., Melo, C., Israelian, G., Bouchy, F., Mayor, M., ...
Context: During the past years photometric surveys, later complemented by follow-up radial-velocity measurements, have revealed the presence of several new extra-solar transiting planets, in very...
Santos, N. C, Pont, F., Melo, C., Israelian, G., Bouchy, F., Mayor, M., ...
Context: During the past years photometric surveys, later complemented by follow-up radial-velocity measurements, have revealed the presence of several new extra-solar transiting planets, in very...
Abundances of refractory elements in the atmospheres of stars with extrasolar planets (2005)
Gilli, G., Israelian, G., Ecuvillon, A., Santos, N. C., Mayor, M.
This work presents a uniform and homogeneous study of chemical abundances of refractory elements in 101 stars with and 94 without known planetary companions. We carry out an in-depth investigation of...
Ecuvillon, A., Israelian, G., Santos, N. C., Mayor, M., Gilli, G.
We present the [X/H] trends as function of the elemental condensation temperature Tc in 88 planet host stars and in a volume-limited comparison sample of 33 dwarfs without detected planetary...
Abundance ratios of volatile vs. refractory elements: hints of pollutions? (2005)
Ecuvillon, A., Israelian, G., Santos, N. C., Mayor, M., Gilli, G.
We present the abundance ratios [X/H] of a large set of chemical species with condensation temperatures from 75 to 1600 K in an almost complete set of 105 planet-host stars and in a volume-limited...
Oxygen abundances in planet-harbouring stars. Comparison of different abundance indicators (2005)
Ecuvillon, A., Israelian, G., Santos, N. C., Shchukina, N. G., Mayor, M., Rebolo, R.
We present a detailed and uniform study of oxygen abundances in 155 solar type stars, 96 of which are planet hosts and 59 of which form part of a volume-limited comparison sample with no known...
Outbursts on normal stars. FH Leo misclassified as a novalike variable (2005)
Dall, T. H., Schmidtobreick, L., Santos, N. C., Israelian, G.
We present high resolution spectroscopy of the common proper motion system FH Leo (components HD 96273 and BD+07 2411B), which has been classified as a novalike variable due to an outburst observed...
Spectroscopic metallicities for planet-host stars: extending the samples (2005)
Santos, N. C., Israelian, G., Mayor, M., Bento, J. P., Almeida, P. C., Sousa, S. G., ...
We present stellar parameters and metallicities for 29 planet-host stars, as well as for a large volume-limited sample of 53 stars not known to be orbited by any planetary-mass companion. These stars...
Abundances of Na, Mg and Al in stars with giant planets (2005)
Beirao, P., Santos, N. C., Israelian, G., Mayor, M.
We present Na, Mg and Al abundances in a set of 98 stars with known giant planets, and in a comparison sample of 41 ``single'' stars. The results show that the [X/H] abundances (with X = Na, Mg and...
On the nature of Lithium-rich giant stars: constraints from Beryllium abundances (2005)
Melo, C. H. F., De Laverny, P., Santos, N. C., Israelian, G., Randich, S., Nascimento Jr., J. D. Do, ...
We have derived beryllium abundances for 7 Li-rich giant (A(Li) > 1.5) stars and 10 other Li-normal giants, with the aim of investigating the origin of the Lithium in the Li-rich giants. In...
On the kinematics of the neutron star low mass X-ray binary Cen X-4 (2005)
Hernández, J. I. González, Rebolo, R., Peñarrubia, J., Casares, J., Israelian, G.
We present the first determination of the proper motion of the neutron star low mass X-ray binary {Cen X-4} measured from relative astrometry of the secondary star using optical images at different...
On the kinematics of the neutron star low mass X-ray binary Cen X-4 (2005)
González Hernández, J. I., Rebolo, R., Peñarrubia, J., Casares, J., Israelian, G.
We present the first determination of the proper motion of the neutron star low mass X-ray binary Cen X-4 measured from relative astrometry of the secondary star using optical images at different...
Are beryllium abundances anomalous in stars with giant planets? (2004)
Santos, N. C., Israelian, G., Lopez, R. J Garcia, Mayor, M., Rebolo, R., Randich, S., ...
In this paper we present beryllium (Be) abundances in a large sample of 41 extra-solar planet host stars, and for 29 stars without any known planetary-mass companion, spanning a large range of...
Beryllium anomalies in solar-type field stars (2004)
Santos, N. C., Israelian, G., Randich, S., Lopez, R. J. Garcia, Rebolo, R.
We present a study of beryllium (Be) abundances in a large sample of field solar-type dwarfs and sub-giants spanning a large range of effective temperatures. The analysis shows that Be is severely...
C, S, Zn and Cu abundances in planet-harbouring stars (2004)
Ecuvillon, A., Israelian, G., Santos, N. C., Mayor, M., Villar, V., Bihain, G.
We present a detailed and uniform study of C, S, Zn and Cu abundances in a large set of planet host stars, as well as in a homogeneous comparison sample of solar-type dwarfs with no known...
Cerón, J. M. Castro, Gorosabel, J., Castro-Tirado, A. J., Sokolov, V. V., Afanasiev, V. L., Fatkhullin, T. A., ...
We present optical and NIR (near infrared) follow up observations of the GRB 001109 from 1 to 300 days after the burst. No transient emission was found at these wavelengths within this GRB's (Gamma...
Galactic Evolution of Nitrogen (2004)
Israelian, G., Ecuvillon, A., Rebolo, R., Lopez, R. Garcia, Bonifacio, P., Molaro, P.
We present detailed spectroscopic analysis of nitrogen abundances in 31 unevolved metal-poor stars analysed by spectral synthesis of the near-UV NH band at 3360 A observed at high resolution with...
Cu and Zn in the early Galaxy (2004)
Bihain, G., Israelian, G., Rebolo, R., Bonifacio, P., Molaro, P.
We present Cu and Zn abundances for 38 FGK stars, mostly dwarfs, spanning a metallicity range between solar and [Fe/H] =-3. The abundances were obtained using Kurucz's local thermal equilibrium (LTE)...
Chemical Abundances in the Secondary Star in the Black Hole Binary A0620-00 (2004)
Gonzalez-Hernandez, Jonay I., Rebolo, R., Israelian, G., Casares, J., Maeder, A., Meynet, G.
Using a high resolution spectrum of the secondary star in the black hole binary A0620-00, we have derived the stellar parameters and veiling caused by the accretion disk in a consistent way. We have...
Israelian, G., Shchukina, N., Rebolo, R., Basri, G., Gonzalez-Hernandez, J. I., Kajino, T.
We report the results of a non-LTE Fe, O and Mg abundance analysis of the carbon-nitrogen-rich ultra-metal-poor giants CS29498--043 and CS22949--037. The abundance of oxygen has been derived from...
Nitrogen abundances in Planet-harbouring stars (2004)
Ecuvillon, A., Israelian, G., Santos, N. C., Mayor, M., López, R. J. García, Randich, S.
We present a detailed spectroscopic analysis of nitrogen abundances in 91 solar-type stars, 66 with and 25 without known planetary mass companions. All comparison sample stars and 28 planet hosts...
Castro Cerón, J. M., Gorosabel, J., Castro-Tirado, A. J., Sokolov, V. V., Afanasiev, V. L., Fatkhullin, T. A., ...
Santos, N. C., Israelian, G., Mayor, M.
We present stellar parameters and metallicities, obtained from a detailed spectroscopic analysis, for a large sample of 98 stars known to be orbited by planetary mass companions (almost all known...
Chemical abundances of planet-host stars: Results for alpha and Fe-group elements (2003)
Bodaghee, A., Santos, N. C., Israelian, G., Mayor, M.
In this paper, we present a study of the abundances of Si, Ca, Sc, Ti, V, Cr, Mn, Co, and Ni in a large set of stars known to harbor giant planets, as well as in a comparison sample of stars not...
Lobel, A., Dupree, A. K., Stefanik, R. P., Torres, G., Israelian, G., Morrison, N., ...
We present an overview of the spectral variability of the peculiar F-type hypergiant Rho Cas, obtained from our long-term monitoring campaigns over the past 8.5 years with four spectrographs in the...
The Search for the Afterglow of the Dark GRB 001109 (2003)
Castro Ceron, J.M., Gorosabel, J., Castro-Tirado, A.J., Sokolov, V., Afanasiev, V.L., Fatkhullin, T.A., ...
The search for the afterglow of the dark GRB 001109 (2003)
Castro Cerón, J. M., Gorosabel, J., Castro-Tirado, A. J., Sokolov, V. V., Afanasiev, V. L., Fatkhullin, T. A., ...
The Millennium Outburst of the Cool Hypergiant Rho Cassiopeiae: Spectroscopy and Modeling (2002)
Lobel, A., Dupree, A. K., Stefanik, R. P., Torres, G., Israelian, G., Morrison, N., ...
Between 2000 June and September an exceptional variability phase occurred in the peculiar F-type hypergiant Rho Cas, when the V-brightness dimmed by at least a full magnitude. The star recovered from...
Santos, N. C., Israelian, G., Mayor, M., Rebolo, R., Udry, S.
In this article we present a detailed spectroscopic analysis of more than 50 extra-solar planet host stars. Stellar atmospheric parameters and metallicities are derived using high resolution and high...
Properties of the PCygni wind found using the Self Absorption Curve method (2002)
Muratorio, G., Markova, N., Friedjung, M., Israelian, G.
We have used the optical lines of N II and Fe III to study the wind of the luminous blue variable P Cyg. This was performed by applying a version of the Self Absorption Curve (SAC) method, involving...
Beryllium abundances in stars hosting giant planets (2002)
Santos, N. C., Lopez, R. J. Garcia, Israelian, G., Mayor, M., Rebolo, R., Garcia-Gil, A., ...
We have derived beryllium abundances in a wide sample of stars hosting planets, with spectral types in the range F7V-K0V, aimed at studying in detail the effects of the presence of planets on the...
The metal-rich nature of stars with planets (2001)
Santos, N. C., Israelian, G., Mayor, M.
With the goal of confirming the metallicity "excess" present in stars with planetary-mass companions, we present in this paper a high-precision spectroscopic study of a sample of dwarfs included in...
Oxygen in the Very Early Galaxy (2001)
Israelian, G., Rebolo, R., Lopez, R. Garcia, Bonifacio, P., Molaro, P., Basri, G., ...
Oxygen abundances in a sample of ultra-metal-poor subdwarfs have been derived from measurements of the oxygen triplet at 7771--5 A and OH lines in the near UV performed in high-resolution and high...
Chemical analysis of 8 recently discovered extra-solar planet host stars (2000)
Santos, N. C., Israelian, G., Mayor, M.
We present the chemical analysis of a new set of stars known to harbor low mass companions, namely HD 1237, HD 52265, HD 82943, HD 83443, HD 169830, and HD 202206. In addition, we have also analyzed...
A Theory of Gamma-Ray Bursts (2000)
Brown, G. E., Lee, H. K., Israelian, G., Bethe, H. A.
We present a specific scenario for the link between GRB and hypernovae, based on Blandford-Znajek extraction of black-hole spin energy. Such a mechanism requires a high angular momentum in the...
The spectral variations of the O-type runaway supergiant HD 188209 (2000)
Israelian, G., Herrero, A., Musaev, F., Kaufer, A., Galeev, A., Galazutdinov, G., ...
We report spectral time series of the late O-type runaway supergiant HD 188209. Radial velocity variations of photospheric absorption lines with a possible quasi-period ~ 6.4 days have been detected...
Early Galactic Evolution of Carbon, Nitrogen and Oxygen (2000)
Israelian, G., Lopez, R. Garcia, Rebolo, Rafael
We present results on carbon, nitrogen, and oxygen abundances for a sample of unevolved metal-poor stars with metallicities in the range -0.3< [Fe/H]< -3. Oxygen abundances derived from different...
A theory of gamma-ray bursts (2000)
Brown, G.E., Lee, H.K., Israelian, G., Bethe, H.A.
Recent observations and theoretical considerations have linked gamma-ray bursts with ultra-bright type Ibc supernovae (`hypernovae'). We here work out a specific scenario for this connection. Based...
The effect of continuum scattering processes on spectral line formation (1999)
The effect of scattering processes in the continuum on the formation of spectral lines in a static atmosphere with an arbitrary distribution of the internal energy sources is investigated using...
Israelian, G., Lobel, A., Schmidt, M. R.
High-resolution near-ultraviolet spectra of the yellow hypergiants HR 8752 and rho Cassiopeiae indicate high effective temperatures placing both stars near the T_eff border of the ``yellow...
P Cygni: An Extraordinary Luminous Blue Variable (1999)
P Cygni is a prototype for understanding mass loss from massive stars. This textbook star is known first of all because of two great eruptions in the 17th century. In the first half of this century...
Oxygen abundances in unevolved metal-poor stars from near-UV OH lines (1998)
Israelian, G., Lopez, R. Garcia, Rebolo, R.
We have performed a detailed oxygen abundance analysis of 23 metal-poor (-3.0