Search Publications
On the Origin of Fast-rotating Stars. I. Photometric Calibration and Results of AO-assisted BVRI+Hα Imaging of NGC 330 with SAMI/SOAR
Navarete, Felipe; Ticiani dos Santos, Pedro; Carciofi, Alex Cavaliéri +1 more
Hα emission is a clear indicator of circumstellar activity in Be stars, historically employed to assess the classical Be star (CBe) population in young open clusters (YOCs). The YOC NGC 330 in the Small Magellanic Cloud exhibits a large known fraction of CBe stars and was selected for a pilot study to establish a comprehensive methodology for iden…
Pulsed Iron Line Emission from the First Galactic Ultraluminous X-Ray Pulsar Swift J0243.6+6124
Zhang, S.; Tao, L.; Zhang, S. N. +14 more
We report the phase-resolved spectral results of the first Galactic pulsating ultraluminous X-ray source (PULX) Swift J0243.6+6124, modeling its 2017–2018 outburst peak using data collected by the Hard X-ray Modulation Telescope (Insight-HXMT). The broad energy coverage of Insight-HXMT allows us to obtain a more accurate spectral continuum to redu…
Results of the follow-up of ANTARES neutrino alerts
Cenko, S. B.; André, M.; Chaty, S. +188 more
High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. To look for transient sources associated with neutrino emission, a follow-up program of neutrino alerts has been operating within the ANTARES collaboration since 2009. This program, named TAToO, has triggere…
Stellar properties of an actively accreting Algol-type eclipsing binary 2M16212643+2136590
Stassun, Keivan G.; Kounkel, Marina; Sun, Meng +2 more
Interacting binary stars undergo evolution that is significantly different from single stars, thus, a larger sample of such systems with precisely determined stellar parameters is needed to understand the complexities of this process. We present an analysis of a hierarchical triple containing a spectroscopically double-lined eclipsing binary, 2M16…
Binary Fraction in Galactic Star Clusters: FSR 866, NGC 1960, and STOCK 2
Carraro, G.; Yalyalieva, L.; Glushkova, E. +1 more
The study of binary stars in different astronomical environments offers insights into the dynamical state of the hosting stellar systems. The binary fraction in fact plays a crucial role in the dynamical evolution of stellar systems, regulating processes like mass segregation and dynamical heating, and in some cases leading to the formation of exo…
Radio Proper Motions of the Nearby Ultra-Cool Dwarf Binary VHS 1256−1257AB
Loinard, L.; Zapata, L. A.; Rodríguez, L. F. +1 more
The proper motions of a source obtained at different epochs or in different spectral regions should in principle be consistent. However, in the case of a binary source or a source with associated ejecta, they could be different depending on the epochs when the observations were made and on what emission is traced in each spectral region. In this p…
EC 19529-4430: SALT identifies the most carbon- and metal-poor extreme helium star
Jeffery, C. S.; Woolf, V. M.; Miszalski, B. +2 more
EC 19529-4430 was identified as a helium-rich star in the Edinburgh-Cape (EC) Survey of faint-blue objects and subsequently resolved as a metal-poor extreme helium (EHe) star in the Southern African Large Telescope (SALT) survey of chemically peculiar hot subdwarfs. This paper presents a fine analysis of the SALT high-resolution spectrum. EC 19529…
Diffuse interstellar bands in Gaia DR3 RVS spectra. New measurements based on machine learning
Schultheis, M.; Zwitter, T.; Zhao, H. +1 more
Diffuse interstellar bands (DIBs) are weak and broad interstellar absorption features in astronomical spectra that originate from unknown molecules. To measure DIBs in spectra of late-type stars more accurately and more efficiently, we developed a random forest model to isolate the DIB features from the stellar components. We applied this method t…
The β Pictoris b Hill sphere transit campaign. II. Searching for the signatures of the β Pictoris exoplanets through time delay analysis of the δ Scuti pulsations
Mamajek, Eric; Stevenson, Kevin B.; Kalas, Paul +34 more
The β Pictoris system is the closest known stellar system with directly detected gas giant planets, an edge-on circumstellar disc, and evidence of falling sublimating bodies and transiting exocomets. The inner planet, β Pictoris c, has also been indirectly detected with radial velocity (RV) measurements. The star is a known δ Scuti pulsator, and t…
Long-term Monitoring of Didymos with the LCOGT Network and MRO after the DART Impact
Lister, Tim; Chatelain, Joseph; Gomez, Edward +8 more
The world's first planetary defense test mission was carried out in late 2022 by NASA's Double Asteroid Redirection Test (DART) mission. The main DART spacecraft, which was accompanied by the ASI-provided LICIACube cubesat, intentionally impacted Dimorphos, the smaller secondary of the near-Earth object binary system (65803) Didymos, on 2022 Septe…