Publications (96)
New ATLAS9 And MARCS Model Atmosphere Grids for the Apache Point Observatory Galactic Evolution Experiment (APOGEE)
Sz. Mészáros, C. Allende Prieto, B. Edvardsson +8
We present a new grid of model photospheres for the SDSS-III/APOGEE survey of stellar populations of the Galaxy, calculated using the ATLAS9 and MARCS codes. New opacity distributi…
Red supergiant star studies with CO5BOLD and Optim3D
B. Plez, A. Chiavassa
We describe recent work focused towards a better understanding of red supergiant stars using 3D radiative-hydrodynamics (RHD) simulations with CO5BOLD. A small number of simulation…
Atmospheric dynamics of red supergiant stars and applications to Interferometry
A. Chiavassa, B. Plez, E. Josselin +1
We have written a 3D radiative transfer code that computes emerging spectra and intensity maps. We derive from radiative hydrodynamic (RHD) simulations of RSG stars carried out wit…
New H-band Stellar Spectral Libraries for the SDSS-III/APOGEE survey
O. Zamora, D. A. Garcia-Hernandez, C. Allende Prieto +18
The Sloan Digital Sky Survey--III (SDSS--III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) has obtained high resolution (R 22,500), high signal-to-noise r…
Tomography of the atmosphere of long-period variable stars
A. Jorissen, M. Dedecker, B. Plez +2
This paper reviews the results obtained so far with the newly developed tomographic technique, which probes the velocity field across the atmosphere of long-period variable (LPV) s…
Fundamental parameters of 16 late-type stars derived from their angular diameter measured with VLTI/AMBER
P. Cruzalèbes, A. Jorissen, Y. Rabbia +7
Thanks to their large angular dimension and brightness, red giants and supergiants are privileged targets for optical long-baseline interferometers. Sixteen red giants and supergia…
New analysis of the two carbon-rich stars CS 22948-27 and CS 29497-34 : binarity and neutron-capture elements
B. Barbuy, M. Spite, F. Spite +4
We have carried out a new determination of abundances in the very metal-poor CH/CN strong stars CS 29497-34 and CS 22948-27, using high-resolution spectra obtained with the HARPS s…
Optical and near-infrared spectrophotometric properties of Long Period Variables and other luminous red stars
R. Alvarez, A. Lancon, B. Plez +1
Based on a new and large sample of optical and near-infrared spectra obtained at the Mount Stromlo and Siding Spring Observatories (Lancon & Wood 1998; Lancon & Wood, in preparatio…
Nitrogen isotopes in AGB carbon stars and presolar SiC grains: a challenge for stellar nucleosynthesis
R. Hedrosa, C. Abia, M. Busso +5
Isotopic ratios of C, N, Si, and trace heavy elements in presolar SiC grains from meteorites provide crucial constraints to nucleosynthesis. A long-debated issue is the origin of t…
Radiative hydrodynamics simulations of red supergiant stars: I. interpretation of interferometric observations
A. Chiavassa, B. Plez, E. Josselin +1
Context. It has been suggested that convection in Red Supergiant (RSG) stars gives rise to large-scale granules causing observable surface inhomogeneities. This convection is also…
First stars VI - Abundances of C, N, O, Li, and mixing in extremely metal-poor giants. Galactic evolution of the light elements
M. Spite, R. Cayrel, B. Plez +11
We have investigated the poorly-understood origin of nitrogen in the early Galaxy by determining N abundances in 35 extremely metal-poor halo giants (22 stars have [Fe/H]<-3.0) usi…
Measurement of stellar age from uranium decay
R. Cayrel, V. Hill, T. Beers +10
The ages of the oldest stars in the Galaxy indicate when star formation began, and provide a minimum age for the Universe. Radioactive dating of meteoritic material and stars relie…
First Stars XI. Chemical composition of the extremely metal-poor dwarfs in the binary CS 22876--032
J. I. González Hernández, P. Bonifacio, H. -G. Ludwig +15
We have used high-resolution, high-S/N ratio spectra from the UVES spectrograph at the ESO VLT telescope. Long-term radial-velocity measurements and broad-band photometry allow us…
Tomography of cool giant and supergiant star atmospheres II. Signature of convection in the atmosphere of the red supergiant star Cep
K. Kravchenko, A. Chiavassa, S. Van Eck +4
Red supergiants are cool massive stars and are the largest and the most luminous stars in the universe. They are characterized by irregular or semi-regular photometric variations,…
TOPoS V: Abundance ratios in a sample of very metal-poor turn-off stars
P. François, E. Caffau, P. Bonifacio +12
Extremely metal-poor stars are keys to understand the early evolution of our Galaxy. The ESO large programme TOPoS has been tailored to analyse a new set of metal-poor turn-off sta…
Red Supergiant Stars as Cosmic Abundance Probes: KMOS Observations in NGC 6822
L. R. Patrick, C. J. Evans, B. Davies +5
We present near-IR spectroscopy of red supergiant (RSG) stars in NGC 6822, obtained with the new VLT-KMOS instrument. From comparisons with model spectra in the J-band we determine…
First stars IV.CS 29497-030: Evidence for operation of the s-process at very low metallicity
T. Sivarani, P. Bonifacio, P. Molaro +12
We present an abundance analysis of the very metal-poor, carbon-enhanced star CS 29497-030. Our results indicate that this unusually hot turnoff star (Teff = 6650K, log g = 3.5) ha…
Chemical analysis of carbon stars in the Local Group: I. The Small Magellanic Cloud and the Sagittarius dwarf spheroidal galaxy
P. De Laverny, C. Abia, I. Dominguez +5
We present the first results of our ongoing chemical study of carbon stars in the Local Group of galaxies. We used spectra obtained with UVES at the 8.2 m Kueyen-VLT telescope and…
R-process pattern in the Very-Metal-Poor Halo Star CS31082-001
V. Hill, B. Plez, R. Cayrel +1
The very-metal-poor halo star CS31082-001 was discovered to be very strongly r-process-enhanced during the course of a VLT+UVES high-resolution follow-up of metal-poor stars identi…
CH in stellar atmospheres: an extensive linelist
T. Masseron, B. Plez, S. Van Eck +7
The advent of high-resolution spectrographs and detailed stellar atmosphere modelling has strengthened the need for accurate molecular data. Carbon-enhanced metal-poor (CEMP) stars…
UBVJHK synthetic photometry of Galactic O stars
F. Martins, B. Plez
The development of powerful infrared observational technics enables the study of very extincted objects and young embedded star forming regions. This is especially interesting in t…
VLTI/AMBER spectro-interferometric imaging of VX Sgr's inhomogenous outer atmosphere
A. Chiavassa, S. Lacour, F. Millour +8
Aims. We aim to explore the photosphere of the very cool late-type star VX Sgr and in particular the existence and characterization of molecular layers above the continuum forming…
First stars IX -Mixing in extremely metal-poor giants. Variation of the 12C/13C, [Na/Mg] and [Al/Mg] ratios
M. Spite, R. Cayrel, V. Hill +11
Extremely metal-poor (EMP) stars preserve a fossil record of the composition of the ISM when the Galaxy formed. It is crucial, however, to verify whether internal mixing has modifi…
An in-depth spectroscopic examination of molecular bands from 3D hydrodynamical model atmospheres. II. Carbon-enhanced metal-poor 3D model atmospheres
A. J. Gallagher, E. Caffau, P. Bonifacio +4
Context. Tighter constraints on metal-poor stars we observe are needed to better understand the chemical processes of the early Universe. Computing a stellar spectrum in 3D allows…
First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
R. Cayrel, E. Depagne, M. Spite +11
In the framework of an ESO Large Programme high quality spectra of 70 very metal-poor dwarfs and giants were obtained with the VLT-UVES combination. This paper reports the detailed…
TOPoS: II. On the bimodality of carbon abundance in CEMP stars. Implications on the early chemical evolution of galaxies
P. Bonifacio, E. Caffau, M. Spite +18
In the course of the TOPoS (Turn Off Primordial Stars) survey, aimed at discovering the lowest metallicity stars, we have found several carbon-enhanced metal-poor (CEMP) stars. We…
First stars XII. Abundances in extremely metal-poor turnoff stars,and comparison with the giants
P. Bonifacio, M. Spite, R. Cayrel +13
CONTEXT:The detailed chemical abundances of extremely metal-poor (EMP) stars are key guides to understanding the early chemical evolution of the Galaxy. Most existing data are, how…
Theoretical analysis of surface brightness-colour relations for late-type stars using MARCS model atmospheres
A. Salsi, N. Nardetto, B. Plez +1
Surface brightness-colour relations (SBCRs) are largely used for general studies in stellar astrophysics and for determining extragalactic distances. Based on simulated spectra of…
A VLT-UVES spectrscopic analysis of C-rich Fe-poor stars
T. Masseron, B. Plez, F. Primas +2
Large surveys of very metal-poor stars have revealed in recent years that a large fraction of these objects were carbon-rich, analogous to the more metal-rich CH-stars. The abundan…
Near-infrared narrow-band photometry of M-giant and Mira stars: models meet observations
R. Alvarez, B. Plez
From near-infrared, narrow-band photometry of 256 oxygen-rich Mira variables we obtain evidence about the loops that these stars follow in colour-colour diagrams. We also find a ph…
POLLUX : a database of synthetic stellar spectra
A. Palacios, M. Gebran, E. Josselin +4
Synthetic spectra are needed to determine fundamental stellar and wind parameters of all types of stars. They are also used for the construction of theoretical spectral libraries h…
Imaging the heart of astrophysical objects with optical long-baseline interferometry
J. -P. Berger, F. Malbet, F. Baron +21
The number of publications of aperture-synthesis images based on optical long-baseline interferometry measurements has recently increased due to easier access to visible and infrar…
The formation of G-band bright points. I: Standard LTE modelling
D. Kiselman, R. J. Rutten, B. Plez
Assuming LTE, we synthesise solar G band spectra from the semiempirical flux-tube model of Briand Solanki (1995). The results agree with observed G-band bright-point contrasts with…
Tomography of cool giant and supergiant star atmospheres. I. Validation of the method
K. Kravchenko, S. Van Eck, A. Chiavassa +3
Cool giant and supergiant star atmospheres are characterized by complex velocity fields originating from convection and pulsation processes which are not fully understood yet. The…
Red Supergiants as cosmic abundance probes: the first direct metallicity determination of NGC 4038 in the Antennae
C. Lardo, B. Davies, R-P. Kudritzki +5
We present a direct determination of the stellar metallicity in the close pair galaxy NGC~4038 (D = 20 Mpc) based on the quantitative analysis of moderate resolution KMOS/VLT spect…
ISO-SWS calibration and the accurate modelling of cool-star atmospheres: I. Method
L. Decin, C. Waelkens, K. Eriksson +5
A detailed spectroscopic study of the ISO-SWS data of the red giant Alpha Tau is presented, which enables not only the accurate determination of the stellar parameters of Alpha Tau…
When binaries keep track of recent nucleosynthesis: The Zr - Nb pair in extrinsic stars as an s-process diagnostic
D. Karinkuzhi, S. Van Eck, A. Jorissen +9
Barium stars are s-process enriched giants. They owe their chemical peculiarities to a past mass transfer phase. During which they were polluted by their binary companion, which at…
A holistic approach to carbon-enhanced metal-poor stars
T. Masseron, J. A. Johnson, B. Plez +4
By considering the various CEMP subclasses separately, we try to derive, from the specific signatures imprinted on the abundances, parameters (such as metallicity, mass, temperatur…
Elemental abundances of metal poor carbon rich lead star: CS29497-030
T. Sivarani, P. Bonifacio, P. Molaro +12
We present here the abundance analysis of a metal poor carbon rich lead star, CS29497-030. High resolution and high signal to noise spectra were obtained using the UVES spectrograp…
X-Shooter GTO: evidence for a population of extremely metal-poor, alpha-poor stars
E. Caffau, P. Bonifacio, P. Francois +12
The extremely metal-poor stars are the direct descendants of the first generation stars. They carry the chemical signature of the pristine Universe at the time they formed, shortly…
TOPoS: IV. Chemical abundances from high-resolution observations of seven EMP stars
P. Bonifacio, E. Caffau, M. Spite +15
Extremely metal-poor stars provide us with indirect information on the first generations of massive stars. The TOPoS survey has been designed to increase the census of these stars…
Lithium during the AGB evolution in young open clusters of the Large Magellanic cloud
C. Maceroni, V. testa, B. Plez +2
We present the results of mid-resolution spectroscopy in the LiI 6708 AA spectral region of Asymptotic Giant Branch (AGB) stars belonging to young open clusters of the Large Magell…
Envelope tomography of long-period variable stars III. Line-doubling frequency among Mira stars
R. Alvarez, A. Jorissen, B. Plez +3
This paper presents statistics of the line-doubling phenomenon in a sample of 81 long-period variable (LPV) stars of various periods, spectral types and brightness ranges. When cor…
The ESO Large Programme First Stars
P. Bonifacio, J. Andersen, S. Andrievsky +19
In ESO period 65 (April-September 2000) the large programme 165.N-0276, led by Roger Cayrel, began making use of UVES at the Kueyen VLT telescope. Known within the Team and outside…
First stars VII. Lithium in extremely metal poor dwarfs
P. Bonifacio, P. Molaro, T. Sivarani +12
Aims. This study aims to determine the level and constancy of the Spite plateau as definitively as possible from homogeneous high-quality VLT-UVES spectra of 19 of the most metal-p…
Chemical Abundances in Twelve Red Giants of the Large Magellanic Cloud from High-Resolution Infrared Spectroscopy
V. V. Smith, K. H. Hinkle, K. Cunha +10
High-resolution infrared spectra (R=50,000) have been obtained for twelve red-giant members of the LMC with the Gemini South 8.3-meter telescope plus Phoenix spectrometer. Quantita…
The effect of winds on atmospheric layers of red supergiants II. Modelling VLTI/GRAVITY and MATISSE observations of AH Sco, KW Sgr, V602 Car, CK Car and V460 Car
G. González-TorÃ, M. Wittkowski, B. Davies +1
Mass loss plays a crucial role in the lives of massive stars, especially as the star leaves the main sequence and evolves to the red supergiant (RSG) phase. However, the physical p…
First stars X. The nature of three unevolved Carbon-Enhanced Metal-Poor stars
T. Sivarani, T. C. Beers, P. Bonifacio +13
From high-resolution VLT/UVES spectra (R~43,000), we determine abundances or upper limits for Li, C, N, O, and other important elements, as well as 12C/13C isotopic ratio for three…
First Stars II. Elemental abundances in the extremely metal-poor star CS 22949--037: A diagnostic of early massive supernovae
E. Depagne, V. Hill, M. Spite +10
CS 22949--037 is one of the most metal-poor giants known ([Fe/H]), and it exhibits large overabundances of carbon and nitrogen (Norris et al.). Using VLT-UVES spectra…
Rubidium-Rich Asymptotic Giant Branch Stars
D. A. Garcia-Hernandez, P. Garcia-Lario, B. Plez +3
A long debated issue concerning the nucleosynthesis of neutron-rich elements in Asymptotic Giant Branch (AGB) stars is the identification of the neutron source. We report intermedi…
Envelope tomography of long-period variable stars: I. The Schwarzschild mechanism and the Balmer emission lines
R. Alvarez, A. Jorissen, B. Plez +2
This paper is the first one in a series devoted to the study of the dynamics of the atmospheres of long-period variable stars. Results from a two-month-long monitoring of the Mira…
The metal-poor end of the Spite plateau. 1: Stellar parameters, metallicities and lithium abundances
L. Sbordone, P. Bonifacio, E. Caffau +16
We present VLT-UVES Li abundances for 28 halo dwarf stars between [Fe/H]=-2.5 and -3.5, 10 of which have [Fe/H]<-3. Four different T_eff scales have been used. Direct Infrared Flux…
Rb-rich Asymptotic Giant Branch stars in the Magellanic Clouds
D. A. Garcia-Hernandez, A. Manchado, D. L. Lambert +6
We present high-resolution (R~60,000) optical spectra of a carefully selected sample of heavily obscured and presumably massive O-rich Asymptotic Giant Branch (AGB) stars in the Ma…
The AMBRE project: A new synthetic grid of high-resolution FGKM stellar spectra
P. de Laverny, A. Recio-Blanco, C. C. Worley +1
Large grids of synthetic spectra covering a widespread range of stellar parameters are mandatory for different stellar and (extra-)Galactic physics applications. Such large grids c…
A primordial star in the heart of the Lion
E. Caffau, P. Bonifacio, P. François +14
Context: The discovery and chemical analysis of extremely metal-poor stars permit a better understanding of the star formation of the first generation of stars and of the Universe…
Lithium and zirconium abundances in massive Galactic O-rich AGB stars
D. A. Garcia-Hernandez, P. Garcia-Lario, B. Plez +4
Lithium and zirconium abundances (the latter taken as representative for s-process enrichment) are determined for a large sample of massive Galactic O-rich AGB stars, for which hig…
ISO-SWS calibration and the accurate modelling of cool-star atmospheres - II. General results
L. Decin, B. Vandenbussche, C. Waelkens +5
The fine calibration of the ISO-SWS detectors (Infrared Space Observatory - Short Wavelength Spectrometer) has proven to be a delicate problem. We therefore present a detailed spec…
ISO impact on stellar models and vice versa
L. Decin, C. Waelkens, K. Eriksson +5
We present a detailed spectroscopic study of a sample of bright, mostly cool, stars observed with the Short-Wavelength Spectrometer (SWS) on board the Infrared Space Observatory (I…
How the StarDICE photometric calibration of standard stars can improve cosmological constraints?
T. Souverin, J. Neveu, M. Betoule +16
The number of type Ia supernova (SNe Ia) observations will grow significantly within the next decade, mainly thanks to the Legacy Survey of Space and Time (LSST) undertaken by the…
Lead abundance in the uranium star CS 31082-001
B. Plez, V. Hill, R. Cayrel +6
In a previous paper we were able to measure the abundance of uranium and thorium in the very-metal poor halo giant BPS CS 31082-001, but only obtained an upper limit for the abunda…
Radiative hydrodynamics simulations of red supergiant stars: II. simulations of convection on Betelgeuse match interferometric observations
A. Chiavassa, X. Haubois, J. S. Young +4
Context. The red supergiant (RSG) Betelgeuse is an irregular variable star. Convection may play an important role in understanding this variability. Interferometric observations ca…
Potassium: a new actor on the globular cluster chemical evolution stage. The case of NGC 2808
A. Mucciarelli, M. Bellazzini, T. Merle +3
We derive [K/Fe] abundance ratios for 119 stars in the globular cluster NGC 2808, all of them having O, Na, Mg and Al abundances homogeneously measured in previous works. We detect…
Radiative hydrodynamics simulations of red supergiant stars. IV gray versus non-gray opacities
A. Chiavassa, B. Freytag, T. Masseron +1
Red supergiants are massive evolved stars that contribute extensively to the chemical enrichment of our Galaxy. It has been shown that convection in those stars gives rise to large…
Circumstellar effects on the Rb abundances in O-rich AGB stars
O. Zamora, D. A. Garcia-Hernandez, B. Plez +1
For the first time we explore the circumstellar effects on the Rb (and Zr) abundance determination in O-rich asymptotic giant branch (AGB) stars by considering the presence of a ga…
Design and performance of a Collimated Beam Projector for telescope transmission measurement using a broadband light source
K. Sommer, J. Cohen-Tanugi, B. Plez +9
Type Ia supernovae are the most direct cosmological probe to study dark energy in the recent Universe, for which the photometric calibration of astronomical instruments remains one…
More lead stars
S. Van Eck, S. Goriely, A. Jorissen +1
The standard model for the operation of the s-process in asymptotic giant branch (AGB) stars predicts that low-metallicity ([Fe/H] <= -1) AGB stars should exhibit large overabundan…
CS 30322-023: an ultra metal-poor TP-AGB star?
T. Masseron, S. Van Eck, B. Famaey +6
With [Fe/H] = -3.5, CS 30322-023 is the most metal-poor star to exhibit a clear s-process signature and the most metal-poor ``lead star'' known. CS 30322-023 is also remarkable in…
NLTE analysis of the methylidyne radical (CH) molecular lines in metal-poor stellar atmospheres
S. A. Popa, R. Hoppe, M. Bergemann +3
An analysis of the CH molecule in non-local thermodynamic equilibrium (NLTE) is performed for the physical conditions of cool stellar atmospheres typical of red giants (log g = 2.0…
First Stars XIV. Sulfur abundances in extremely metal-poor (EMP) stars
Monique Spite, E. Caffau, S. M. Andrievsky +15
Sulfur is important: the site of its formation is uncertain, and at very low metallicity the trend of [S/Fe] against [Fe/H] is controversial. Below [Fe/H]=-2.0, [S/Fe] remains cons…
The Evolution of Copper in the Globular Cluster Omega Centauri
K. Cunha, V. V. Smith, N. B. Suntzeff +3
Copper abundances are presented for 40 red-giant stars in Omega Cen as well as 15 red-giant members of the globular clusters NGC288, NGC362, NGC3201, NGC6752, and M4. A comparison…
Why are massive O-rich AGB stars in our Galaxy not S-stars?
D. A. Garcia-Hernandez, P. Garcia-Lario, B. Plez +4
We present the main results derived from a chemical analysis carried out on a large sample of galactic O-rich AGB stars using high resolution optical spectroscopy (R~40,000-50,000)…
Comparative Modelling of the Spectra of Cool Giants
T. Lebzelter, U. Heiter, C. Abia +24
Our ability to extract information from the spectra of stars depends on reliable models of stellar atmospheres and appropriate techniques for spectral synthesis. Various model code…
Atmosphere of Betelgeuse before and during the Great Dimming event revealed by tomography
K. Kravchenko, A. Jorissen, S. Van Eck +7
Despite being the best studied red supergiant star in our Galaxy, the physics behind the photometric variability and mass loss of Betelgeuse is poorly understood. Moreover, recentl…
Atmospheric dynamics and the mass loss process in red supergiant stars
E. Josselin, B. Plez
Red supergiant stars represent a key phase in the evolution of massive stars. Recent radiative hydrodynamic simulations suggest that their atmospheres may be the location of large-…
VLT Observations of Turnoff stars in the Globular Cluster NGC 6397
F. Thévenin, C. Charbonnel, J. A. de Freitas Pacheco +4
VLT-UVES high resolution spectra of seven turnoff stars in the metal-poor globular cluster NGC 6397 have been obtained. Atmospheric parameters and abundances of several elements (L…
The PLATO 2.0 Mission
H. Rauer, C. Catala, C. Aerts +159
PLATO 2.0 has recently been selected for ESA's M3 launch opportunity (2022/24). Providing accurate key planet parameters (radius, mass, density and age) in statistical numbers, it…
TOPoS: I. Survey design and analysis of the first sample
E. Caffau, P. Bonifacio, L. Sbordone +14
The metal-weak tail of the metallicity distribution function (MDF) of the Galactic Halo stars contains crucial information on the formation mode of the first generation of stars. T…
Envelope tomography of long-period variable stars II. Method
R. Alvarez, A. Jorissen, B. Plez +3
A tomographic method is described that makes it possible to follow the propagation of shock waves across the photosphere of long-period variable stars. The method relies on the cor…
TOPoS: III. An ultra iron-poor multiple CEMP system
E. Caffau, P. Bonifacio, M. Spite +15
One of the primary objectives of the TOPoS survey is to search for the most metal-poor stars. Our search has led to the discovery of one of the most iron-poor objects known, SDSS\,…
s-Process Nucleosynthesis in Carbon Stars
C. Abia, I. Dominguez, R. Gallino +6
We present the first detailed and homogeneous analysis of the s-element content in Galactic carbon stars of N-type. Abundances of Sr,Y, Zr (low-mass s-elements, or ls) and of Ba, L…
The Chemical Composition of Carbon C(N) stars
C. Abia, I. Dominguez, R. Gallino +5
A chemical study of normal Galactic C(N) carbon stars is presented. Abundances of Li, CNO isotopes and s-elements are derived. The derived abundances of s-elements nicely agree wit…
The effect of winds on atmospheric layers of red supergiants I. Modelling for interferometric observations
G. González-TorÃ, M. Wittkowski, B. Davies +2
Red supergiants (RSGs) are evolved massive stars in a stage preceding core-collapse supernova. The physical processes that trigger mass loss in their atmospheres are still not full…
Exploring circumstellar effects on the lithium and calcium abundances in massive Galactic O-rich AGB stars
V. Pérez-Mesa, O. Zamora, D. A. GarcÃa-Hernández +6
We previously explored the circumstellar effects on the Rb and Zr abundances in massive Galactic O-rich AGB stars. Here we are interested in the role of the extended atmosphere in…
A homogeneous analysis of globular clusters from the APOGEE survey with the BACCHUS code. I. The Northern clusters
T. Masseron, D. A. GarcÃa-Hernández, Sz. Mészáros +12
We analyze a large sample of 885 GCs giants from the APOGEE survey. We used the Cannon results to separate the red giant branch and the asymptotic giant branch stars, not only allo…
Using the CIFIST grid of CO5BOLD 3D model atmospheres to study the effects of stellar granulation on photometric colours. I. Grids of 3D corrections in the UBVRI, 2MASS, Hipparcos, Gaia, and SDSS systems
P. Bonifacio, E. Caffau, H. -G. Ludwig +9
The atmospheres of cool stars are temporally and spatially inhomogeneous due to the effects of convection.The influence of this inhomogeneity, referred to as granulation, on colour…
Age Dating Stellar Populations in the Near Infrared: An absolute age indicator from the presence/absence of red supergiants
J. Zachary Gazak, N. Bastian, R. P. Kudritzki +4
The determination of age is a critical component in the study of a population of stellar clusters. In this letter we present a new absolute age indicator for young massive star clu…
The extreme r-element rich, iron-poor halo giant CS31082-001: Implications for the r-process site(s) and radioactive cosmochronology
V. Hill, B. Plez, R. Cayrel +10
We present a high-resolution spectroscopic analysis of the bright (V=11.7), extreme halo giant CS31082-001 ([Fe/H] = -2.9), obtained in an ESO-VLT Large Programme dedicated to very…
Observational constraints on the origin of the elements II. 3D non-LTE formation of Ba ii lines in the solar atmosphere
A. J. Gallagher, M. Bergemann, R. Collet +5
Context. The pursuit of more realistic spectroscopic modelling and consistent abundances has led us to begin a new series of papers designed to improve current solar and stellar ab…
ISO-SWS calibration and the accurate modelling of cool-star atmospheres - III. A0 to G2 stars
L. Decin, B. Vandenbussche, C. Waelkens +4
Vega, Sirius, Beta Leo, Alpha Car and Alpha Cen A belong to a sample of twenty stellar sources used for the calibration of the detectors of the Short-Wavelength Spectrometer on boa…
Rubidium and zirconium abundances in massive Galactic asymptotic giant branch stars revisited
V. Perez-Mesa, O. Zamora, D. A. Garcia-Hernandez +4
Luminous Galactic OH/IR stars have been identified as massive (>4-5 M_s) AGB stars experiencing HBB and Li production. Their Rb abundances and [Rb/Zr] ratios derived from hydrostat…
First stars XVI. STIS/HST abundances of heavy-elements in the uranium-rich star CS 31082-001
C. Siqueira Mello, M. Spite, B. Barbuy +14
Detailed abundances of the elements produced by r-process nucleosynthesis in various circumstances are our best observational clues to their origin, since the site(s) of r-element…
Lithium abundances in CEMP stars
T. Masseron, J. A. Johnson, S. Lucatello +4
Carbon-enhanced metal-poor (CEMP) stars are believed to show the chemical imprints of more massive stars (M > 0.8 Msun) that are now extinct. In particular, it is expected that the…
First stars XIII. Two extremely metal-poor RR Lyrae stars?
C. J. Hansen, B. Nordstroem, P. Bonifacio +11
The chemical composition of extremely metal-poor stars (EMP stars; [Fe/H]<~ -3) is a unique tracer of early nucleosynthesis in the Galaxy. As such stars are rare, we wish to find c…
PLATO as it is: a legacy mission for Galactic archaeology
A. Miglio, C. Chiappini, B. Mosser +102
Deciphering the assembly history of the Milky Way is a formidable task, which becomes possible only if one can produce high-resolution chrono-chemo-kinematical maps of the Galaxy.…
First Stars VIII -- Enrichment of the neutron-capture elements in the early Galaxy
P. Francois, E. Depagne, V. Hill +12
Our aim is to measure accurate, homogeneous neutron-capture element abundances for the sample of 32 EMP giant stars studied earlier in this series, including 22 stars with [Fe/H] $…
ISO-SWS calibration and the accurate modelling of cool-star atmospheres - IV. G9 to M2 stars
L. Decin, B. Vandenbussche, C. Waelkens +5
presented. The 2.38 -- 4.08 micron wavelength-range of band 1 of ISO-SWS (Short-Wavelength Spectrometers on board of the Infrared Space Observatory) in which many different molecul…