Nucleosynthesis and molecular processes in the late stages of Stellar Evolution

    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.

    Principal investigator

    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.

    Related publications

    Self-enrichment in globular clusters: the extreme He-rich populationof NGC 2808 2018MNRAS.479.5325D
    A new linelist for the A3Π-X3Σ- transition of the NH free radical 2018JQSRT.217...29F
    A new line list for the A2Σ+ -X2 Π electronic transition of OH 2018JQSRT.217..416Y
    Forty-four New and Known M-dwarf Multiples in the SDSS-III/APOGEE M-dwarf Ancillary Science Sample 2018AJ....156...45S
    Kepler-503b: An Object at the Hydrogen Burning Mass Limit Orbiting a Subgiant Star 2018ApJ...861L...4C
    Binary Companions of Evolved Stars in APOGEE DR14: Search Method and Catalog of ∼5000 Companions 2018AJ....156...18P
    Stellar and Planetary Characterization of the Ross 128 Exoplanetary System from APOGEE Spectra 2018ApJ...860L..15S
    Signatures of the Galactic bar on stellar kinematics unveiled by APOGEE 2018MNRAS.478.1231P
    Chemical Composition of Two Bright, Extremely Metal-poor Stars from the SDSS MARVELS Pre-survey 2018ApJ...859..114B
    Disk-like Chemistry of the Triangulum-Andromeda Overdensity as Seen by APOGEE 2018ApJ...859L...8H
    Age-resolved chemistry of red giants in the solar neighbourhood 2018MNRAS.477.2326F
    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment 2018ApJS..235...42A
    Heavy-element yields and abundances of asymptotic giant branch models with a Small Magellanic Cloud metallicity 2018MNRAS.477..421K
    Magnesium isotopes: a tool to understand self-enrichment in globular clusters 2018MNRAS.477..438V
    Chemical Abundances of Main-sequence, Turnoff, Subgiant, and Red Giant Stars from APOGEE Spectra. I. Signatures of Diffusion in the Open Cluster M67 2018ApJ...857...14S
    StarHorse: a Bayesian tool for determining stellar masses, ages, distances, and extinctions for field stars 2018MNRAS.476.2556Q
    The Metal-poor non-Sagittarius (?) Globular Cluster NGC 5053: Orbit and Mg, Al, and Si Abundances 2018ApJ...855...38T
    Massive Stars in the SDSS-IV/APOGEE SURVEY. I. OB Stars 2018ApJ...855...68R
    GTC/CanariCam Mid-IR Imaging of the Fullerene-rich Planetary Nebula IC 418: Searching for the Spatial Distribution of Fullerene-like Molecules 2018AJ....155..105D
    A view of the H-band light-element chemical patterns in globular clusters under the AGB self-enrichment scenario 2018MNRAS.475.3098D
    Submerged carbon arc in liquid benzene: GC-MS analysis of the products 2017FNCN...25..576C
    Gas and dust from solar metallicity AGB stars 2018MNRAS.475.2282V
    280 one-opposition near-Earth asteroids recovered by the EURONEAR with the Isaac Newton Telescope 2018A&A...609A.105V
    A photometric study of globular clusters observed by the APOGEE survey 2018MNRAS.475.1633M
    Disentangling the Galactic Halo with APOGEE. I. Chemical and Kinematical Investigation of Distinct Metal-poor Populations 2018ApJ...852...49H
    Disentangling the Galactic Halo with APOGEE. II. Chemical and Star Formation Histories for the Two Distinct Populations 2018ApJ...852...50F
    Binary stars in the Galactic thick disc 2018MNRAS.473.2984I
    Elemental Abundances of Kepler Objects of Interest in APOGEE. I. Two Distinct Orbital Period Regimes Inferred from Host Star Iron Abundances 2018AJ....155...68W
    C/O ratios in planetary nebulae with dual-dust chemistry from faint optical recombination lines 2018MNRAS.473.4476G
    Where does galactic dust come from? 2018MNRAS.473.4538G
    12C/13C isotopic ratios in red-giant stars of the open cluster NGC 6791 2018MNRAS.474.4810S
    The interaction of the halo around the butterfly planetary nebula NGC 650-1 with the interstellar medium 2018MNRAS.475..932R
    The First APOKASC Catalog of Kepler Dwarf and Subgiant Stars 2017ApJS..233...23S
    The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory 2017ApJS..233...25A
    C70 Fullerene charge-transfer interaction with alkylnaphthalenes, pinenes, and a diene 2017FNCN...25..505G
    Charge-transfer interaction between C60 fullerene and alkylnaphthalenes 2017FNCN...25..223G
    Target Selection for the SDSS-IV APOGEE-2 Survey 2017AJ....154..198Z
    Rubidium and zirconium abundances in massive Galactic asymptotic giant branch stars revisited 2017A&A...606A..20P
    Adding the s-Process Element Cerium to the APOGEE Survey: Identification and Characterization of Ce ii Lines in the H-band Spectral Window 2017ApJ...844..145C
    APOGEE Chemical Abundances of the Sagittarius Dwarf Galaxy 2017ApJ...845..162H

    Related talks

    No related talks were found.

    Related conferences

    No related conferences were found.