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
-
The 16th Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS SpectraThis paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also includedAhumada, Romina et al.
Advertised on:
72020 -
The SDSS/APOGEE catalogue of HgMn starsWe report on H-band spectra of chemically peculiar Mercury-Manganese (HgMn) stars obtained via the SDSS/APOGEE survey. As opposed to other varieties of chemically peculiar stars such as classical Ap/Bp stars, HgMn stars lack strong magnetic fields and are defined by extreme overabundances of Mn, Hg, and other heavy elements. A satisfactoryChojnowski, S. Drew et al.
Advertised on:
62020 -
From the bulge to the outer disc: StarHorse stellar parameters, distances, and extinctions for stars in APOGEE DR16 and other spectroscopic surveysWe combine high-resolution spectroscopic data from APOGEE-2 survey Data Release 16 (DR16) with broad-band photometric data from several sources as well as parallaxes from Gaia Data Release 2 (DR2). Using the Bayesian isochrone-fitting code StarHorse, we derived the distances, extinctions, and astrophysical parameters for around 388 815 APOGEE starsQueiroz, A. B. A. et al.
Advertised on:
62020 -
A theoretical investigation of the possible detection of C24 in spaceAstronomical infrared spectral features at ~6.6, 9.8 and 20 micronm have recently been suggested as being due to the planar graphene form of C24 carbon cluster. Here we report density functional theory and coupled cluster calculations on wavefunctions stability, relative energies, and infrared spectra of four different types of C24 isomersSadjadi, SeyedAbdolreza et al.
Advertised on:
82020 -
Detection of CH<SUP>+</SUP>, CH and H<SUB>2</SUB> Molecules in the Young Planetary Nebula IC 4997We have detected CH + and CH molecular absorption lines from the youngcompact planetary nebula IC 4997 from high resolution optical spectra. A high-resolution infra-red (H and K bands) spectrum provides detection of H 2 emission lines among many other lines. The H 2 lines provide an excitation temperature of 2100 K which may result from UVRao, N. Kameswara et al.
Advertised on:
72020 -
The Lazy Giants: APOGEE Abundances Reveal Low Star Formation Efficiencies in the Magellanic CloudsWe report the first APOGEE metallicities and α-element abundances measured for 3600 red giant stars spanning a large radial range of both the Large (LMC) and Small Magellanic Clouds, the largest Milky Way (MW) dwarf galaxies. Our sample is an order of magnitude larger than that of previous studies and extends to much larger radial distances. TheseNidever, David L. et al.
Advertised on:
62020 -
Close Binary Companions to APOGEE DR16 Stars: 20,000 Binary-star Systems Across the Color-Magnitude DiagramMany problems in contemporary astrophysics—from understanding the formation of black holes to untangling the chemical evolution of galaxies—rely on knowledge about binary stars. This, in turn, depends on the discovery and characterization of binary companions for large numbers of different kinds of stars in different chemical and dynamicalPrice-Whelan, Adrian M. et al.
Advertised on:
52020 -
Petroleum, coal and other organics in spaceThe petroleum and coal models of the unidentified infrared emissions (UIE), sometimes referred also as unidentified infrared bands (UIBs) has been reviewed mainly based on the work of the authors with the inclusion of unpublished results. It is shown that the petroleum and coal model of the UIE converges and merges quite well with the MAON (MixedCataldo, Franco et al.
Advertised on:
52020 -
Spectral Classification of B Stars: The Empirical Sequence Using SDSS-IV/APOGEE Near-IR DataWe present a semi-empirical spectral classification scheme for normal B-type stars using near-infrared (NIR) spectra (1.5-1.7 μm) from the Sloan Digital Sky Survey Apache Point Observatory Galaxy Evolution Experiment (APOGEE2)-N data release 14 (DR14) database. The main motivation for working with B-type stars is their importance in the evolutionRamírez-Preciado, Valeria G. et al.
Advertised on:
52020 -
Identification of a Group III CEMP-no Star in the Dwarf Spheroidal Galaxy Canes Venatici ICEMP-no stars, a subclass of carbon-enhanced metal-poor (CEMP) stars, are one of the most significant stellar populations in galactic archeology, because they dominate the low end of the metallicity distribution function, providing information on the early star formation and chemical-evolution history of the Milky Way and its satellite galaxiesYoon, Jinmi et al.
Advertised on:
52020 -
[Li@C60]PF6: Infrared spectra from 90K to 523K; Determination of the molar extinction coefficients and integrated molar absorptivityGarcía-Hernández, D. A. et al.
Advertised on:
62020 -
The age-chemical abundance structure of the Galaxy I: evidence for a late-accretion event in the outer disc at z ∼ 0.6We investigate the age-chemical abundance structure of the outer Galactic disc at a galactocentric distance of r > 10 kpc as recently revealed by the SDSS/APOGEE survey. Two sequences are present in the [α/Fe]-[Fe/H] plane with systematically different stellar ages. Surprisingly, the young sequence is less metal rich, suggesting a recent dilutionLian, Jianhui et al.
Advertised on:
42020 -
The Open Cluster Chemical Abundances and Mapping Survey. IV. Abundances for 128 Open Clusters Using SDSS/APOGEE DR16The Open Cluster Chemical Abundances and Mapping (OCCAM) survey aims to constrain key Galactic dynamical and chemical evolution parameters by the construction of a large, comprehensive, uniform, infrared-based spectroscopic data set of hundreds of open clusters. This fourth contribution from the OCCAM survey presents analysis using Sloan DigitalDonor, John et al.
Advertised on:
52020 -
The chemical compositions of accreted and in situ galactic globular clusters according to SDSS/APOGEEStudies of the kinematics and chemical compositions of Galactic globular clusters (GCs) enable the reconstruction of the history of star formation, chemical evolution, and mass assembly of the Galaxy. Using the latest data release (DR16) of the SDSS/APOGEE survey, we identify 3090 stars associated with 46 GCs. Using a previously defined kinematicHorta, Danny et al.
Advertised on:
42020 -
Characterization of M-stars in the LMC in the JWST eraWe study the M-type asymptotic giant branch (AGB) population of the Large Magellanic Cloud (LMC) by characterizing the individual sources in terms of the main properties of the progenitors and of the dust present in the circumstellar envelope. To this aim we compare the combination of the spectroscopic and photometric data collected by SpitzerMarini, E. et al.
Advertised on:
42020 -
Stellar Characterization of M Dwarfs from the APOGEE Survey: A Calibrator Sample for M-dwarf MetallicitiesWe present spectroscopic determinations of the effective temperatures, surface gravities, and metallicities for 21 M dwarfs observed at high resolution (R ∼ 22,500) in the H band as part of the Sloan Digital Sky Survey (SDSS)-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. The atmospheric parameters and metallicities areSouto, Diogo et al.
Advertised on:
22020 -
Characterizing the companion AGBs using surface chemical composition of barium starsBarium stars are one of the important probes to understand the origin and evolution of slow neutron-capture process elements in the Galaxy. These are extrinsic stars, where the observed s-process element abundances are believed to have an origin in the now invisible companions that produced these elements at their asymptotic giant branch (AGB)Shejeelammal, J. et al.
Advertised on:
32020 -
Metallicity and α-Element Abundance Gradients along the Sagittarius Stream as Seen by APOGEEUsing 3D positions and kinematics of stars relative to the Sagittarius (Sgr) orbital plane and angular momentum, we identify 166 Sgr stream members observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) that also have Gaia DR2 astrometry. This sample of 63/103 stars in the Sgr trailing/leading arm is combined with an APOGEEHayes, Christian R. et al.
Advertised on:
12020 -
The Central Star of NGC 2346 as a Clue to Binary Evolution through the Common Envelope PhaseWe present an analysis of the binary central star of the planetary nebula NGC 2346 based on archival data from the International Ultraviolet Explorer, and new low- and high-resolution optical spectra (3700-7300 Å). By including in the spectral analysis the contribution of both stellar and nebular continuum, we reconciled long-time discrepant UV andGómez-Muñoz, M. A. et al.
Advertised on:
112019 -
Physical parameters of red supergiants in dwarf irregular galaxies in the Local GroupContext. Increasing the statistics of evolved massive stars in the Local Group enables investigating their evolution at different metallicities. During the late stages of stellar evolution, the physics of some phenomena, such as episodic and systematic mass loss, are not well constrained. For example, the physical properties of red supergiantsBritavskiy, N. E. et al.
Advertised on:
112019
