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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The Gaia-ESO Survey: the origin and evolution of s-process elementsContext. Several works have found an increase of the abundances of the s-process neutron-capture elements in the youngest Galactic stellar populations. These trends provide important constraints on stellar and Galactic evolution and they need to be confirmed with large and statistically significant samples of stars spanning wide age and distanceMagrini, L. et al.
Advertised on:
92018 -
The Gaia-ESO Survey: properties of newly discovered Li-rich giantsAims: We report 20 new lithium-rich giants discovered within the Gaia-ESO Survey, including the first Li-rich giant with an evolutionary stage confirmed by CoRoT (Convection, Rotation and planetary Transits) data. We present a detailed overview of the properties of these 20 stars. Methods: Atmospheric parameters and abundances were derived in modelSmiljanic, R. et al.
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92018 -
Modeling dust emission in PN IC 418We investigated the infrared (IR) dust emission from PN IC 418, using a detailed model controlled by a previous determination of the stellar properties and the characteristics of the photoionized nebula, keeping as free parameters the dust types, amounts, and distributions relative to the distance of the central star. The model includes the ionizedGómez-Llanos, V. et al.
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92018 -
The APOGEE-2 Survey of the Orion Star-forming Complex. II. Six-dimensional StructureWe present an analysis of spectroscopic and astrometric data from APOGEE-2 and Gaia DR2 to identify structures toward the Orion Complex. By applying a hierarchical clustering algorithm to the six-dimensional stellar data, we identify spatially and/or kinematically distinct groups of young stellar objects with ages ranging from 1 to 12 Myr. We alsoKounkel, M. et al.
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92018 -
A Chemical and Kinematical Analysis of the Intermediate-age Open Cluster IC 166 from APOGEE and Gaia DR2IC 166 is an intermediate-age open cluster (OC) (˜1 Gyr) that lies in the transition zone of the metallicity gradient in the outer disk. Its location, combined with our very limited knowledge of its salient features, make it an interesting object of study. We present the first high-resolution spectroscopic and precise kinematical analysis of IC 166Schiappacasse-Ulloa, J. et al.
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92018 -
APOGEE Data Releases 13 and 14: Data and AnalysisThe data and analysis methodology used for the SDSS/APOGEE Data Releases 13 and 14 are described, highlighting differences from the DR12 analysis presented in Holtzman et al. Some improvement in the handling of telluric absorption and persistence is demonstrated. The derivation and calibration of stellar parameters, chemical abundances, andHoltzman, J. A. et al.
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92018 -
APOGEE Data Releases 13 and 14: Stellar Parameter and Abundance Comparisons with Independent AnalysesData from the SDSS-IV/Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) have been released as part of SDSS Data Releases 13 (DR13) and 14 (DR14). These include high-resolution H-band spectra, radial velocities, and derived stellar parameters and abundances. DR13, released in 2016 August, contained APOGEE data for roughly 150,000Jönsson, H. et al.
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92018 -
The Open Cluster Chemical Abundances and Mapping Survey. II. Precision Cluster Abundances for APOGEE Using SDSS DR14The Open Cluster Chemical Abundances and Mapping (OCCAM) survey aims to produce a comprehensive, uniform, infrared-based spectroscopic data set for hundreds of open clusters, and to constrain key Galactic dynamical and chemical parameters from this sample. This second contribution from the OCCAM survey presents analysis of 259 member stars with [FeDonor, J. et al.
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102018 -
The Double Dust Envelopes of R Coronae Borealis StarsThe study of extended, cold dust envelopes surrounding R Coronae Borealis (RCB) stars began with their discovery by the Infrared Astronomical Satellite. RCB stars are carbon-rich supergiants characterized by their extreme hydrogen deficiency and their irregular and spectacular declines in brightness (up to 9 mag). We have analyzed new and archivalMontiel, E. J. et al.
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102018 -
Evolved stars in the Local Group galaxies - II. AGB, RSG stars, and dust production in IC10We study the evolved stellar population of the Local Group galaxy IC10, with the aim of characterizing the individual sources observed and to derive global information on the galaxy, primarily the star-formation history and the dust production rate. To this aim, we use evolutionary sequences of low- and intermediate-mass (M 8 M_{⊙}) stars, evolvedDell'Agli, F. et al.
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102018 -
Self-enrichment in globular clusters: the extreme He-rich populationof NGC 2808Almost several decades after the discovery of the first multiple populations in galactic globular clusters (GC), the debate on their formation is still extremely current and NGC 2808 remains one of the best benchmark to test any scenario for their origin and the evolution. In this work, we focus on the chemical composition of stars belonging to theDi Criscienzo, M. et al.
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102018 -
A new linelist for the A3Π-X3Σ- transition of the NH free radicalA new linelist for the A3Π-X3Σ- electronic transition of NH has been prepared using line positions from the literature and calculated line intensities. High level ab initio calculations were performed with the MOLPRO program to obtain the A-X transition dipole moment function. Potential energy curves and line strengths were calculated with Le Roy'sFernando, A. M. et al.
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92018 -
A new line list for the A2Σ+ -X2 Π electronic transition of OHA new line list for the A2Σ+ -X2 Π electronic transition of OH has been calculated. Line positions have been taken from the literature and refitted with Western's PGOPHER program. Line intensities were calculated using a new ab initio Transition Dipole Moment Function (TDMF) obtained with Molpro 2012. The new TDMF and the potential functions fromYousefi, M. et al.
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92018 -
Forty-four New and Known M-dwarf Multiples in the SDSS-III/APOGEE M-dwarf Ancillary Science SampleBinary stars make up a significant portion of all stellar systems. Consequently, an understanding of the bulk properties of binary stars is necessary for a full picture of star formation. Binary surveys indicate that both multiplicity fraction and typical orbital separation increase as functions of primary mass. Correlations with higher-orderSkinner, J. et al.
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82018 -
Kepler-503b: An Object at the Hydrogen Burning Mass Limit Orbiting a Subgiant StarUsing spectroscopic radial velocities with the Apache Point Observatory Galaxy Evolution Experiment (APOGEE) instrument and Gaia distance estimates, we demonstrate that Kepler-503b, currently considered a validated Kepler planet, is in fact a brown-dwarf/low-mass star in a nearly circular 7.2-day orbit around a subgiant star. Using a mass estimateCañas, C. I. et al.
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72018 -
Binary Companions of Evolved Stars in APOGEE DR14: Search Method and Catalog of ∼5000 CompanionsMulti-epoch radial velocity measurements of stars can be used to identify stellar, substellar, and planetary-mass companions. Even a small number of observation epochs can be informative about companions, though there can be multiple qualitatively different orbital solutions that fit the data. We have custom-built a Monte Carlo sampler (The Joker)Price-Whelan, A. M. et al.
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72018 -
Stellar and Planetary Characterization of the Ross 128 Exoplanetary System from APOGEE SpectraThe first detailed chemical abundance analysis of the M-dwarf (M4.0) exoplanet-hosting star Ross 128 is presented here, based upon near-infrared (1.5–1.7 μm), high-resolution (R ∼ 22,500) spectra from the SDSS Apache Point Galactic Evolution Experiment survey. We determined precise atmospheric parameters T eff = 3231 ± 100 K, log g = 4.96 ± 0.11Souto, D. et al.
Advertised on:
62018 -
Signatures of the Galactic bar on stellar kinematics unveiled by APOGEEBars are common galactic structures in the local universe that play an important role in the secular evolution of galaxies, including the Milky Way. In particular, the velocity distribution of individual stars in our galaxy is useful to shed light on stellar dynamics, and provides information complementary to that inferred from the integrated lightPalicio, P. A. et al.
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72018 -
Chemical Composition of Two Bright, Extremely Metal-poor Stars from the SDSS MARVELS Pre-surveySDSS J082625.70+612515.10 (V = 11.4 [Fe/H] = ‑3.1) and SDSS J134144.60+474128.90 (V = 12.4 [Fe/H] = ‑3.2) were observed with the SDSS 2.5m telescope as part of the SDSS MARVELS spectroscopic pre-survey and identified as extremely metal-poor (EMP; [Fe/H]Bandyopadhyay, A. et al.
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62018 -
Disk-like Chemistry of the Triangulum-Andromeda Overdensity as Seen by APOGEEThe nature of the Triangulum-Andromeda (TriAnd) system has been debated since the discovery of this distant, low-latitude Milky Way (MW) overdensity more than a decade ago. Explanations for its origin are either as a halo substructure from the disruption of a dwarf galaxy, or a distant extension of the Galactic disk. We test these hypotheses usingHayes, C. R. et al.
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52018
