Start year
1986
Organizational Unit
Organizing institutions
Grants related:
General
Description
Low- to intermediate-mass (M < 8 solar masses, Ms) stars represent the majority of stars in the Cosmos. They finish their lives on the Asymptotic Giant Branch (AGB) - just before they form planetary nebulae (PNe) - where they experience complex nucleosynthetic and molecular processes. AGB stars are important contributors to the enrichment of the interstellar medium where new stars/planets are born (including our own Early Solar System, ESS), and to the chemical evolution of stellar systems like globular clusters (GCs) and galaxies. In particular, the more massive (M > 4-5 Ms) AGB stars synthesize very different (radio)isotopes from those formed by lower mass AGB stars and Supernova detonations, as a consequence of different nucleosynthesis mechanisms. Evolved stars in the transition phase between AGB stars and PNe also form diverse organic compounds like PAHs, and fullerene and graphene molecular nanostructures, being a wonderful laboratory for Astrochemistry. On-going massive surveys like SDSS-IV/APOGEE-2 and the upcoming James Webb Space Telescope (JWST) represent a fundamental step forward to understand the nucleosynthesis and molecular processes in evolved stars. We aim to explore the nucleosynthesis of light and heavy (radio)isotopes in AGB stars and how they contribute to the ESS radioactive inventory as well as to the formation and evolution of GCs and galaxies. We also aim at understanding the top-down formation process of fullerene and graphene molecular nanostructures in evolved stars. Finally, it is intended to perform data mining with the Gaia satellite, in order to study the AGB- PNe evolutionary phase. In addition we aim to use the GALEX database to discover binary central stars in Galactic PNe.
Members
Principal investigator
Domingo Aníbal
García Hernández
Project staff
Arturo
Manchado Torres
Thomas
Masseron
Olga María
Zamora Sánchez
LUCIO
CRIVELLARI
Collaborators
Dr.
P. García Lario
Dr.
G. García Segura
Dr.
L. Stanghellini
Dr.
E. Villaver
Carlos
Allende Prieto
Jorge
García Rojas
Dr.
B. Plez
Dr.
A. Karakas
Dr.
M. Lugaro
Dr.
D. Lambert
Dr.
P. Ventura
Dr.
F. Cataldo
Dr.
Andres Yague
Dr.
Sun Kwok
Dr.
R. Szczerba
Dr.
J.M. Trigo Rodríguez
Dr.
K. Rao
S. Sadjadi
M. Manteiga
C. Dafonte
R. Santoveña
L. Bianchi
Sz. Mészáros
S. Cristallo
L. Piersanti
Results
1. During 2020, we have published 37 papers in high-impact international refereed astronomical journals (including one invited review) and 2 papers in the Chemistry -Physics journal FNCN.
2. Phosphorus-rich stars with an extremely peculiar chemical abundance pattern have been discovered for the first time, challenging the theoretical nucleosynthesis predictions.
3. It was demonstrated that the P-rich star progenitors represent a new site for s-process nucleosynthesis, with important implications for the chemical evolution of our Galaxy.
Scientific activity
Related publications
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Massive Stars in the SDSS-IV/APOGEE-2 Survey. II. OB-stars in the W345 ComplexesIn this work, we have applied a semi-empirical spectral classification method for OB-stars using the APOGEE spectrograph to a sample of candidates in the W3–W4–W5 (W345) complexes. These massive star-forming regions span over 200 pc across the Perseus arm and have a notorious population of massive stars, from which a large fraction are members ofRoman-Lopes, Alexandre et al.
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32019 -
Discovery of Resolved Magnetically Split Lines in SDSS/APOGEE Spectra of 157 Ap/Bp StarsWe report on magnetic field measurements of 157 chemically peculiar A/B stars (Ap/Bp) based on resolved, magnetically split absorption lines present in H-band spectra provided by the Sloan Digital Sky Survey (SDSS)/Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. These stars represent the extreme magnetic end of a stillChojnowski, S. Drew et al.
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32019 -
J-PLUS: Identification of low-metallicity stars with artificial neural networks using SPHINXContext. We present a new methodology for the estimation of stellar atmospheric parameters from narrow- and intermediate-band photometry of the Javalambre Photometric Local Universe Survey (J-PLUS), and propose a method for target pre-selection of low-metallicity stars for follow-up spectroscopic studies. Photometric metallicity estimates for starsWhitten, D. D. et al.
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22019 -
Homogeneous analysis of globular clusters from the APOGEE survey with the BACCHUS code. I. The northern clustersAims: We seek to provide abundances of a large set of light and neutron-capture elements homogeneously analyzed that cover a wide range of metallicity to constrain globular cluster (GC) formation and evolution models. Methods: We analyzed a large sample of 885 GCs giants from the SDSS IV-Apache Point Observatory Galactic Evolution ExperimentMasseron, T. et al.
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22019 -
Identifying Sagittarius Stream Stars by Their APOGEE Chemical Abundance SignaturesThe SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey provides precise chemical abundances of 18 chemical elements for ∼176,000 red giant stars distributed over much of the Milky Way Galaxy (MW), and includes observations of the core of the Sagittarius dwarf spheroidal galaxy (Sgr). The APOGEE chemical abundanceHasselquist, S. et al.
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22019 -
Constraining Metallicity-dependent Mixing and Extra Mixing Using [C/N] in Alpha-rich Field GiantsInternal mixing on the giant branch is an important process which affects the evolution of stars and the chemical evolution of the galaxy. While several mechanisms have been proposed to explain this mixing, better empirical constraints are necessary. Here, we use [C/N] abundances in 26,097 evolved stars from the SDSS-IV/APOGEE-2 Data Release 14 toShetrone, M. et al.
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22019 -
APOGEE [C/N] Abundances across the Galaxy: Migration and Infall from Red Giant AgesWe present [C/N]–[Fe/H] abundance trends from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment survey, Data Release 14 (DR14), for red giant branch stars across the Milky Way (3 kpc R 15 kpc). The carbon-to-nitrogen ratio (often expressed as [C/N]) can indicate the mass of a red giant star, from which an age can be inferredHasselquist, Sten et al.
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22019 -
The Fifteenth Data Release of the Sloan Digital Sky Surveys: First Release of MaNGA-derived Quantities, Data Visualization Tools, and Stellar LibraryTwenty years have passed since first light for the Sloan Digital Sky Survey (SDSS). Here, we release data taken by the fourth phase of SDSS (SDSS-IV) across its first three years of operation (2014 July–2017 July). This is the third data release for SDSS-IV, and the 15th from SDSS (Data Release Fifteen; DR15). New data come from MaNGA—we releaseAguado, D. S. et al.
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22019 -
The Gaia-ESO Survey: impact of extra mixing on C and N abundances of giant starsContext. The Gaia-ESO Public Spectroscopic Survey using FLAMES at the VLT has obtained high-resolution UVES spectra for a large number of giant stars, allowing a determination of the abundances of the key chemical elements carbon and nitrogen at their surface. The surface abundances of these chemical species are known to change in stars duringLagarde, N. et al.
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12019 -
Kepler-730: A Hot Jupiter System with a Close-in, Transiting, Earth-sized PlanetKepler-730 is a planetary system hosting a statistically validated hot Jupiter in a 6.49 day orbit and an additional transiting candidate in a 2.85 day orbit. We use spectroscopic radial velocities from the APOGEE-2N instrument, Robo-AO contrast curves, and Gaia distance estimates to statistically validate the planetary nature of the additionalCañas, C. I. et al.
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12019 -
Chemical and Kinematic Analysis of CN-strong Metal-poor Field Stars in LAMOST DR3The large amount of chemical and kinematic information available in large spectroscopic surveys has inspired the search for chemically peculiar stars in the field. Though these metal-poor field stars ([Fe/H]Tang, B. et al.
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12019 -
Discovery of Stars Surrounded by Iron Dust in the Large Magellanic CloudWe consider a small sample of oxygen-rich, asymptotic giant branch stars in the Large Magellanic Cloud, observed by the Spitzer Space Telescope, exhibiting a peculiar spectral energy distribution, which can hardly be explained by the common assumption that dust around Asymptotic Giant Branch stars is primarily composed of silicate grains. WeMarini, E. et al.
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12019 -
Evolved stars in the Local Group galaxies - III. AGB and RSG stars in Sextans AWe study the evolved stellar population of the galaxy Sextans A. This galaxy is one of the lowest metallicity dwarfs in which variable asymptotic giant branch stars have been detected, suggesting that little metal enrichment took place during the past history. The analysis consists in the characterization of a sample of evolved stars, based onDell'Agli, F. et al.
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22019 -
Measuring the expansion and age of the nova shell IPHASX J210204.7 + 471015The parallax expansion and kinematics of a nova shell can be used to assess its age and distance, and to investigate the interaction of the ejecta with the circumstellar medium. These are key to understand the expansion and dispersal of the nova ejecta in the Galaxy. Multi-epoch images and high-dispersion spectroscopic observations of the recentlySantamaría, E. et al.
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32019 -
Phase-transfer catalysis in the oxidation of C60 and C70 fullerene with KMnO4 and crown etherThe KMnO4 oxidation reaction of C60 or C70 fullerenes in benzene solution proceeds smoothly and almost quantitatively in presence of the crown ether 18-crown-6 as phase-transfer agent. The oxidation reaction was followed spectrophotometrically from the early stages to the completion. Essentially fullerenols or polyhydroxylated fullerenes wereCataldo, F. et al.
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92018 -
Raman, FT-IR spectroscopy and morphology of carbon dust from carbon arc in liquid benzeneThe carbon arc in liquid benzene produces carbon dust in addition to phenylacetyene and a number of other molecular products. The carbon dust was analyzed by Transmission Electron Microscopy (TEM), electron diffraction and Raman spectroscopy, revealing that it consists of a highly structured carbon black with high surface area. The carbon dust fromGarcía-Hernández, D. A. et al.
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102018 -
The Second APOKASC Catalog: The Empirical ApproachWe present a catalog of stellar properties for a large sample of 6676 evolved stars with Apache Point Observatory Galactic Evolution Experiment spectroscopic parameters and Kepler asteroseismic data analyzed using five independent techniques. Our data include evolutionary state, surface gravity, mean density, mass, radius, age, and thePinsonneault, M. H. et al.
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122018 -
Comprehensive comparison between APOGEE and LAMOST. Radial velocities and atmospheric stellar parametersContext. In the era of massive spectroscopy surveys, automated stellar parameter pipelines and their validation are extremely important for an efficient scientific exploitation of the spectra. Aims: We undertake a critical and comprehensive comparison of the radial velocities and the main stellar atmosphere parameters for stars in common betweenAnguiano, B. et al.
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122018 -
When binaries keep track of recent nucleosynthesis. The Zr-Nb pair in extrinsic stars as an s-process diagnosticContext. Barium stars are s-process enriched giants. They owe their chemical peculiarities to a past mass transfer phase. During this phase they were polluted by their binary companion, which at the time was an asymptotic giant branch (AGB) star, but is now an extinct white dwarf. Barium stars are thus ideal targets for understanding andKarinkuzhi, D. et al.
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102018 -
The Origin of the 300 km s‑1 Stream near Segue 1We present a search for new members of the 300 km s‑1 stream (300S) near the dwarf galaxy Segue 1 using wide-field survey data. We identify 11 previously unknown bright stream members in the APOGEE-2 and SEGUE-1 and 2 spectroscopic surveys. Based on the spatial distribution of the high-velocity stars, we confirm for the first time that thisFu, Sal Wanying et al.
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102018
