A5082193977- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Molecular Spectroscopy and Structure
- Education Pedagogy and Practices
- Education and Digital Technologies
- Quantum, superfluid, helium dynamics
- Astronomical and nuclear sciences
- Geophysics and Gravity Measurements
- Planetary Science and Exploration
- Historical Art and Architecture Studies
- Astrophysical Phenomena and Observations
- Optical Systems and Laser Technology
- Business and Management Studies
- Optical Polarization and Ellipsometry
- Architecture and Art History Studies
- Environmental Sustainability and Education
- Education and Public Policy
- Inorganic Fluorides and Related Compounds
- Science and Education Research
- Astrophysics and Cosmic Phenomena
Laboratório Nacional de Astrofísica
2020-2024
Universidade Federal de Minas Gerais
2011-2023
Brf (Brazil)
2008
We present a new catalog of 108 Herbig Ae/Be candidate stars identified in the Pico dos Dias Survey, together with 19 previously known candidates and four objects selected from IRAS Faint Source Catalog. These 131 were observed low- and/or medium-resolution spectroscopy, we complement these data high-resolution spectra 39 stars. The great variety Hα line profiles separated according to them. Our study suggests that most time star will double peak profile. Correlations among different...
We report the discovery of 25 new open clusters resulting from a search in dense low galactic latitude fields. also provide, for first time, structural and astrophysical parameters findings 34 other recently discovered using Gaia DR2 data. The candidates were confirmed by jointly inspecting vector point diagrams spatial distribution. discoveries validated matching near known objects comparing their mean astrometric with available literature. A decontamination algorithm was applied to...
ABSTRACT GRB 230812B is a bright and relatively nearby (z = 0.36) long gamma-ray burst (GRB) that has generated significant interest in the community thus been observed over entire electromagnetic spectrum. We report 80 observations X-ray, ultraviolet, optical, infrared, submillimetre bands from GRANDMA (Global Rapid Advanced Network for Multimessenger Addicts) network of observatories observational partners. Adding complementary data literature, we then derive essential physical parameters...
Abstract Star clusters are crucial for understanding how stars evolve. Their colour- magnitude diagrams show the effects of stellar evolution approximately coeval objects with same chemical composition. Furthermore, determination their astrophysical parameters (age, distance, colour excess and metallicity) together spatial distribution provides information about structure Galaxy itself. Using data from Gaia DR3 2MASS catalogues, we develop methodologies characterizing open clusters. Precise...
Aims.We investigate evidence of accretion in a sample 15 Herbig Ae/Be stars to determine whether these events originate remnant gaseous structure from the primordial cloud (rich hydrogen) or metal-rich body (like comets our Solar System). During such analysis we also precise stellar parameters for this stars.
The Sun is located inside an extremely low density and quite irregular volume of the interstellar medium, known as Local Cavity (LC). It has been widely believed that some kind interaction could be occurring between LC Loop I, a nearby superbubble seen in direction Galactic center. As result such interaction, wall neutral dense material, surrounded by ring-shaped feature, would formed at zone. Evidence this structure was previously observed analyzing soft X-ray emission I. Our goal to...
We report the serendipitous discovery of three new open clusters, named UFMG 1, 2 and 3 in field intermediate-age cluster NGC 5999, by using Gaia DR2 data. A colour-magnitude filter tailored for a proper selection main-sequence stars red clump giants turned evident presence 5999 these stellar groups motion space. Their structural parameters were derived from King-profile fittings over their projected distributions isochrone fits performed on clusters cleaned diagrams built with bands to...
ABSTRACT We report the discovery of 34 new open clusters and candidates as a result systematic search carried out in 200 adjacent fields 1 × deg2 area projected towards Galactic bulge, using Gaia DR2 data. The objects were identified characterized by joint analysis their photometric, kinematic, spatial distribution that has been consistently used proved to be effective our previous works. discoveries validated cross-referencing position astrometric parameters with available literature....
Open clusters belonging to star-forming complexes are the leftovers from initial stellar generations. The study of these young systems provides constraints models star formation and evolution as well properties Galactic disc. We aimed at investigating NGC1981, a open cluster in Orion Nebula Region, using near-IR BV (RI)C photometric data.We devised method that accounts for field contamination allows derive membership stars. A new centre was determined by Gaussian fittings 2-D distribution on...
The Sun is located inside an extremely low density region called the Local Bubble (LB). Although they have been studied through a large variety of techniques, contours its neutral boundary, defined by dense wall interstellar gas and dust, are still open issue. Our aim to determine reddening in LB means Strömgren photometry, validating conclusions comparison with high-resolution three-dimensional (3D) hydrodynamical models Loop I bubbles' formation evolution. We obtained color excesses...
ABSTRACT In this study, we characterized 16 objects previously classified as faint or low-contrast Galactic open clusters (OCs). We employed parameters associated with the dynamical evolution of OCs: core (rc), tidal (rt) and half-mass (rhm) radii, age crossing time (tcr). Relations among these were exploited to draw some evolutionary connections. also included 11 OCs previous characterizations provide wider coverage parameter space. The investigated sample spans a considerable range in age,...
A number of stellar open cluster (OC) pairs in the Milky Way occupy similar positions phase space (coordinates, parallax and proper motions) therefore may constitute physically interacting systems. The characterization such objects based on observational data is a fundamental step towards understanding their physical status to investigate pair formation Galaxy. In this work, we employed Gaia EDR3 set 16 OCs distributed as seven aggregates. We determined structural parameters applied...
Most stars in our Galaxy form stellar aggregates, which can become long-lived structures called open clusters (OCs). Along their dynamical evolution, gradual depletion leave some imprints on structure. In this work, we employed astrometric, photometric and spectroscopic data from the \textit{Gaia} DR3 catalogue to uniformly characterize a sample of 60 OCs. Structural parameters (tidal, core half-light radii, respectively, $r_t$, $r_c$ $r_h$), age, mass ($M_{\textrm{clu}}$), distance,...
The stellar content of Galactic open clusters is gradually depleted during their evolution as a result internal relaxation and external interactions. final residues the are called cluster remnants, barely distinguishable from field. We aimed to characterise compare dynamical states set 16 such objects. sample also includes 7 objects that catalogued dynamically evolved clusters. used photometric data 2MASS, astrometric GAIA DR2 decontamination algorithm was applied three-dimensional space...
In this work, we investigate the dynamical properties of 38 Galactic open clusters: 34 them are located at low latitudes (|b| < 10$^{\circ}$) and projected against dense stellar fields; other 4 comparison objects present clearer contrasts with field population. We determine structural time-related parameters that associated clusters' evolution: core ($r_c$), tidal ($r_t$) half-mass ($r_{hm}$) radii, ages ($t$) crossing times ($t_{cr}$). have also incorporated results for 27 previously...
The results of a spectroscopic programme aiming to investigate the kinematics local interstellar medium components towards Southern Coalsack and Chamaeleon-Musca dark clouds are presented. analysis is based upon high-resolution (R ~ 60,000) spectra insterstellar NaI D absorption lines 63 B-type stars (d < 500 pc) selected cover these connecting area defined by Galactic coordinates: 308 > l 294 -22 b 5. radial velocities, column densities, velocity dispersions, colour excess photometric...
The Sun is located inside an extremely low density region of quite irregular shape called the Local Bubble. Close to Bubble, there even larger cavity known as Loop I. A ring-like feature observed in X-ray and HI has been proposed contour bubbles interaction zone around 70 pc. Our goal identify interface between I Bubbles discuss ring's existence using Stromgren uvbyHβdata. We have used uvbyHβdata General Catalogue Photometric Data, covering defined by Galactic coordinates: 250\degr <= l...
ABSTRACT We present the results of a chemical analysis fast and anomalous rotator giants members young open cluster NGC 6124. For this purpose, we carried out abundances mixing sensitive species such as Li, C, N, Na, 12C/13C isotopic ratio, well other for sample four among seven observed ones. This study is based on standard spectral technique using high-resolution spectroscopic data. also performed an investigation rotational velocity ($v\, \sin \, i$) once exhibits abnormal values – giant...
Abstract First detected on 2023 November 4 by the Gravitational-wave Optical Transient Observer, SN 2023wrk is a Type Ia Supernova at 40 Mpc, with significant unburned carbon in outer ejecta. In this note, we present photometric and spectroscopic observations analysis conducted Global Rapid Advanced Network Devoted to Multi-messenger Addict over 115 days period, which includes 78 of measurements. The were contributed both amateur professional astronomers. J. Liu et al. analyzed physical...
At least during the last ten years, Brazilian astronomical community has been asking for an echelle spectrograph 1.6 m telescope installed at Pico dos Dias Observatory (Brazópolis, MG, Brazil, OPD/MCTI/LNA). Among scientific cases are topics related to chemical evolution of Galaxy, asteroseismology, composition and chromospheric activities solar type stars relations between analogues terrestrial planets. During 2009 project finally got started. The called ECHARPE (Espectrógrafo ECHelle de...
GRB~230812B is a bright and relatively nearby ($z =0.36$) long gamma-ray burst (GRB) that has generated significant interest in the community thus been observed over entire electromagnetic spectrum. We report 80 observations X-ray, ultraviolet, optical, infrared, sub-millimeter bands from GRANDMA (Global Rapid Advanced Network for Multi-messenger Addicts) network of observatories observational partners. Adding complementary data literature, we then derive essential physical parameters...
We present a campaign designed to train the GRANDMA network and its infrastructure follow up on transient alerts detect their early afterglows. In preparation for O4 II campaign, we focused GRB as they are expected be an electromagnetic counterpart of gravitational-wave events. Our goal was improve our response start prompt observations soon possible better prepare fourth observational run LIGO-Virgo-Kagra (which started at end May 2023), future missions such SM. To receive, manage send out...