167 citations · 691 across the 25 of their papers we have counts for
25 papers
The VISCACHA survey -- VII. Assembly history of the Magellanic Bridge and SMC Wing from star clusters
R. A. P. Oliveira, F. F. S. Maia, B. Barbuy +15
The formation scenario of the Magellanic Bridge during an encounter between the Large and Small Magellanic Clouds Myr ago, as proposed by -body models, would be impri…
Design of a Skipper CCD Focal Plane for the SOAR Integral Field Spectrograph
Edgar Marrufo Villalpando, Alex Drlica-Wagner, Marco Bonati +14
We present the development of a Skipper Charge-Coupled Device (CCD) focal plane prototype for the SOAR Telescope Integral Field Spectrograph (SIFS). This mosaic focal plane consist…
The VISCACHA survey -- IV. The SMC West Halo in 8D
B. Dias, M. C. Parisi, M. Angelo +18
The structure of the Small Magellanic Cloud (SMC) is very complex, in particular in the periphery that suffers more from the interactions with the Large Magellanic Cloud (LMC). A w…
Discovery of 74 new bright ZZ Ceti stars in the first three years of TESS
A. D. Romero, S. O. Kepler, J. J. Hermes +17
We report the discovery of 74 new pulsating DA white dwarf stars, or ZZ Cetis, from the data obtained by the Transiting Exoplanet Survey Satellite (TESS) mission, from Sectors 1 to…
VVV-WIT-08: the giant star that blinked
Leigh C. Smith, Sergey E. Koposov, Philip W. Lucas +11
We report the serendipitous discovery of a late-type giant star that exhibited a smooth, eclipse-like drop in flux to a depth of 97 per cent. Minimum flux occurred in April 2012 an…
Spectroscopic study of the HII regions in the NGC 1232 galaxy
Fabiana Lima-Costa, Lucimara P. Martins, Alberto Rodríguez-Ardila +1
NGC 1232 is a face-on spiral galaxy that serves as an excellent laboratory for the study of star formation due to its proximity. Recent studies have revealed interesting features a…
The VISCACHA survey -- II. Structure of star clusters in the Magellanic Clouds periphery
J. F. C. Santos, F. F. S. Maia, B. Dias +11
We provide a homogeneous set of structural parameters of 83 star clusters located at the periphery of the Small Magellanic Cloud (SMC) and the Large Magellanic Cloud (LMC). The clu…
Rotational modulation and single g-mode pulsation in the B9pSi star HD174356?
Z. Mikulasek, E. Paunzen, S. Huemmerich +19
Chemically peculiar (CP) stars of the upper main sequence are characterised by specific anomalies in the photospheric abundances of some chemical elements. The group of CP2 stars,…
The nuclear region of NGC 613 -- II. Kinematics and stellar archaeology
Patrícia da Silva, R. B. Menezes, J. E. Steiner
In this work, we continue the study of the central region of NGC 613 by da Silva et al. (2020), by analysing the stellar and gas kinematics and the stellar archaeology in optical a…
Pulsation in the white dwarf HE 1017-1352: confirmation of the class of hot DAV stars
Alejandra D. Romero, L. Antunes Amaral, S. O. Kepler +3
We report the detection of periodic variations on the T_eff ~32 000 K DA white dwarf star HE 1017-1352. We obtained time series photometry using the 4.1 m SOAR telescope on three s…
Linking Compact Dwarf Starburst Galaxies in the RESOLVE Survey to Downsized Blue Nuggets
Michael L. Palumbo, Sheila J. Kannappan, Elaine M. Frazer +12
We identify and characterize compact dwarf starburst (CDS) galaxies in the RESOLVE survey, a volume-limited census of galaxies in the local universe, to probe whether this populati…
The VISCACHA survey -- deep and resolved photometry of star clusters in the Magellanic Clouds
Bruno Dias, Francisco Maia, Leandro Kerber +24
The VISCACHA (VIsible Soar photometry of star Clusters in tApii and Coxi HuguA\footnote{LMC and SMC names in the Tupi-Guarani language spoken by native people in Brazil}) Survey is…
The VISCACHA survey - I. Overview and First Results
Francisco F. S. Maia, Bruno Dias, João F. C. Santos +15
The VISCACHA (VIsible Soar photometry of star Clusters in tApii and Coxi HuguA) Survey is an ongoing project based on deep photometric observations of Magellanic Cloud star cluster…
Star Formation Rate Distribution in the Galaxy NGC 1232
Alexandre Araújo de Souza, Lucimara P. Martins, Alberto Rodríguez-Ardila +1
NGC 1232 is a face-on spiral galaxy and a great laboratory for the study of star-formation due to its proximity. We obtained high spatial resolution Hα images of this galaxy, with…
The sdA problem - II. Photometric and Spectroscopic Follow-up
Ingrid Pelisoli, S. O. Kepler, D. Koester +3
Subdwarf A star (sdA) is a spectral classification given to objects showing H-rich spectra and sub-main sequence surface gravities, but effective temperature lower than the zero-ag…
Orbital parameters and evolutionary status of the highly peculiar binary system HD 66051
E. Paunzen, M. Fedurco, K. G. Helminiak +8
The spectroscopic binary system HD 66051 (V414 Pup) consists of a highly peculiar CP3 (HgMn) star and an A-type component. It also shows out-of-eclipse variability that is due to c…
New SX Phe variables in the globular cluster NGC 288
E. Martinazzi, S. O. Kepler, J. E. S. Costa +4
We report the discovery of two new variable stars in the metal-poor globular cluster NGC 288, found by means of time-series CCD photometry. We classified the new variables as SX Ph…
Discovery of a new PG1159 (GW Vir) Pulsator
S. O. Kepler, Luciano Fraga, Don Earl Winget +3
We report the discovery of pulsations in the spectroscopic PG 1159 type pre-white dwarf SDSS J075415.12+085232.18. Analysis of the spectrum by Werner, Rauch and Kepler (2014) indic…
Asteroseismological study of massive ZZ Ceti stars with fully evolutionary models
A. D. Romero, S. O. Kepler, A. H. Córsico +2
We present the first asteroseismological study for 42 massive ZZ Ceti stars based on a large set of fully evolutionary carbonoxygen core DA white dwarf models characterized by a…
SOAR Adaptive Optics Observations of the Globular Cluster NGC6496
Luciano Fraga, Andrea Kunder, Andrei Tokovinin
We present high-quality BVRI photometric data in the field of globular cluster NGC 6496 obtained with the SOAR Telescope Adaptive Module (SAM). Our observations were collected as p…
Magnetic White Dwarf Stars in the Sloan Digital Sky Survey
S. O. Kepler, Ingrid Pelisoli, Stefan Jordan +10
To obtain a better statistics on the occurrence of magnetism among white dwarfs, we searched the spectra of the hydrogen atmosphere white dwarf stars (DAs) in the Data Release 7 of…
He II 4686 in eta Carinae: collapse of the wind-wind collision region during periastron passage
M. Teodoro, A. Damineli, J. I. Arias +23
The periodic spectroscopic events in eta Carinae are now well established and occur near the periastron passage of two massive stars in a very eccentric orbit. Several mechanisms h…
GALEX and Optical Observations of GW Librae During the Long Decline from Superoutburst
Eric Bullock, Paula Szkody, Anjum S. Mukadam +14
The prototype of accreting, pulsating white dwarfs (GW Lib) underwent a large amplitude dwarf nova outburst in 2007. We used ultraviolet data from GALEX and ground-based optical ph…
Whole Earth Telescope observations of the pulsating subdwarf B star PG 0014+067
M. Vuckovic, S. D. Kawaler
PG 0014+067 is one of the most promising pulsating subdwarf B stars for seismic analysis, as it has a rich pulsation spectrum. The richness of its pulsations, however, poses a fund…