A5101610101- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Solar and Space Plasma Dynamics
- Parvovirus B19 Infection Studies
- Virus-based gene therapy research
- History and Developments in Astronomy
- Astronomical Observations and Instrumentation
Institute of Astronomy and Space Physics
2022-2024
Fundación Ciencias Exactas y Naturales
2023
University of Buenos Aires
2023
Valongo Observatory
2019-2021
National Observatory
2019-2021
Argentine National Observatory
2013
Instituto de Astrofísica de Canarias
1995
We present 6 new transits of the system WASP-4. Together with 28 light curves published in literature, we perform an homogeneous study its parameters and search for variations transit's central times. The final values agree those previously reported, except a slightly lower inclination. find no significant long-term $i$ or $R_{P}/R_{\star}$. $O-C$ mid-transit times do not show signs TTVs greater than 54 s.
We present results from a quantitative spectroscopic analysis conducted on archival Keck/HIRES high-resolution spectra the California-$Kepler$ Survey (CKS) sample of transiting planetary host stars identified $Kepler$ mission. The was based carefully selected set Fe I and II lines, resulting in precise values for stellar parameters effective temperature (T$_{\rm eff}$) surface gravity (log $g$). Combining with $Gaia$ DR2 parallaxes distances, we derived both radii our sample, median internal...
Average magnetic field measurements are presented for 62 M-dwarf members of the Pleiades open cluster, derived from Zeeman-enhanced Fe I lines in H-band. An MCMC methodology was employed to model filling factors using SDSS-IV APOGEE high-resolution spectra, along with radiative transfer code SYNMAST, MARCS stellar atmosphere models, and DR17 spectral line list. There is a positive correlation between mean fields rotation, slow-rotator stars (Rossby number, Ro$>$0.13) exhibiting steeper slope...
Different approaches have been adopted to study short- and long-term stellar magnetic activity, although the mechanisms by which low-mass stars generate large-scale fields are not well understood, it is known that rotation plays a key role. There show cyclical behaviour in their activity can be explained solar dynamo or $\alpha\Omega$ models. However, when studying late-type dwarf stars, necessary implement other indicators analyse activity. In present work, we perform comparative between...
We present independent and self-consistent metallicities for a sample of 807 planet-hosting stars from the California-Kepler Survey an LTE spectroscopic analysis using selected Fe I II lines. Correlations between host-star metallicities, planet radii, planetary architecture (orbital periods - warm or hot multiplicity single multiple), were investigated non-parametric statistical tests. In addition to confirming previous results literature, e.g., that overall host star metallicity...
The physical properties of transiting exoplanets are connected with the their host stars. We present a homogeneous spectroscopic analysis based on spectra FGK-type stars observed Hydra spectrograph WIYN telescope. derived effective temperatures, surface gravities, and metallicities, for 81 by K2 33 from Kepler 1. constructed an Fe I II line list that is adequate R$\sim$18,000 covering 6050-6350 \r{A} adopted technique equivalent width measurements. calculations were done in LTE using Kurucz...
ABSTRACT We present a detailed high-resolution spectroscopic analysis of 12 red giant stars, in single and binaries or multiples systems, classified as members the intermediate-age (631 Myr) open cluster NGC 2539. used FEROS echelle spectra standard LTE to derive atmospheric parameters for stars abundance ratios light elements (Li, C, N), odd-Z (Na, Al), α-elements (Mg, Si, Ca, Ti), Fe-group (Cr, Fe, Ni), n-capture (Y, Zr, Ce, Nd, Eu). Our results show that sample star 2539 has low projected...
ABSTRACT In this study, we undertake a comprehensive investigation of seven red giant stars NGC 4349 (#005, #009, #079, #127, #168, #174, and #203) one non-member star (#053). Accurate abundances 19 chemical species 12C/13C isotopic ratio are determined using high-signal-to-noise FEROS spectra standard spectroscopic analysis. Seven the in our sample present mean iron abundance [Fe/H] = −0.16 ± 0.04, while 4349−053 is classified as cluster, based on membership analysis with upmask code. Also,...
We characterize the radii and masses of star planets in Kepler-59 system, as well their orbital parameters. The parameters are determined through a standard spectroscopic analysis, resulting mass $1.359\pm 0.155\,M_\odot$ radius $1.367\pm 0.078\,R_\odot$. planetary obtained $1.5\pm 0.1\,R_\oplus$ for inner $2.2\pm outer planet. by inversion Transit Timing Variations (TTV) signals. For this, we consider two different data sets, one provided Holczer et al. 2016, with TTVs only planet...
The physical properties of transiting exoplanets are connected with the their host stars. We present a homogeneous spectroscopic analysis based on spectra FGK-type stars observed Hydra spectrograph WIYN telescope. derived effective temperatures, surface gravities, and metallicities, for 81 by K2 33 from Kepler 1. constructed an Fe I II line list that is adequate R$\sim$18,000 covering 6050-6350 Å adopted technique equivalent width measurements. calculations were done in LTE using Kurucz...
Different approaches have been adopted to study short- and long-term stellar magnetic activity, although the mechanisms by which low-mass stars generate large-scale fields are not well understood, it is known that rotation plays a key role. There show cyclical behaviour in their activity can be explained solar dynamo or $αΩ$ models. However, when studying late-type dwarf stars, necessary implement other indicators analyse activity. In present work, we perform comparative between best-known...