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Refining Orbits of Bright Binary Systems
Miroshnichenko, Anatoly S.; Danford, Stephen; Andronov, Ivan L. +3 more
We obtained spectra of several bright binary systems (ζ02 UMa, 2 Lac, and ϕ Aql), which were mostly observed with photographic plates and whose orbits were not determined very accurately. Each system was monitored for a few years with the 81-cm telescope equipped with an échelle spectrograph at the Three College Observatory in North Carolina. The …
Resonant Effects of a Bar on the Galactic Disk Kinematics Perpendicular to Its Plane
Vieira, Katherine; Carraro, Giovanni; Korchagin, Vladimir +2 more
Detailed analysis of kinematics of the Milky Way disk in the solar neighborhood based on the GAIA DR3 catalog reveals the existence of peculiarities in the stellar velocity distribution perpendicular to the galactic plane. We study the influence of resonances—the outer Lindblad resonance and the outer vertical Lindblad resonance—of a rotating bar …
Recent Progress in Finding Binary Systems with the B[e] Phenomenon
Raj, Ashish; Chojnowski, S. Drew; Manset, Nadine +9 more
This paper describes recent studies of the FS CMa-type objects, a group of stars showing the B[e] phenomenon defined in 2007. The objects exhibit strong emission-line spectra with both permitted and forbidden lines suggesting the presence of a B-type star as well as strong IR excesses due to radiation of circumstellar dust. These properties are ha…
New Method to Detect and Characterize Active Be Star Candidates in Open Clusters
Granada, Anahí; Eenmäe, Tõnis; Ghoreyshi, Maziar R. +1 more
With the aim of better understanding the physical conditions under which Be stars form and evolve, it is imperative to further investigate whether poorly studied young open clusters host Be stars. In this work, we explain how data from Gaia DR2 and DR3 can be combined to recover and characterize active Be stars in open clusters. We test our method…
A Scattered Star Group in the Orion A Region of the Milky Way
Kovaleva, Dana; Sapozhnikov, Sergei; Vereshchagin, Sergei +4 more
Using Gaia DR3 data, we identified an extended a ~60 pc group of stars sharing common motion but scattered in space, including from 150 to 300 probable members, named Group V. It can be associated with a group identified by Getman et al. (2019) and by Jerabkova et al. (2019) as a relic of a gas filament, traced by the mutual position of stars afte…
A Comprehensive Study of Soft X-ray Absorption Features in GX 13+1 Using XMM-Newton Observations
Mahato, Rabindra; Baruah, Monmoyuri
In this study, a comprehensive analysis of the reflection grating spectrometer (RGS) data (energy range 0.33 keV to 2.5 keV) of GX 13+1 from the XMM-Newton space observatory was conducted. Numerous absorption lines have been described in earlier publications, although the majority of these investigations focused on the energy range between 3 keV a…
Revealing the Binarity of HD 36030—One of the Hottest Flare Stars
Karpov, Sergey; Németh, Péter; Maryeva, Olga
The Kepler and TESS space missions significantly expanded our knowledge of what types of stars display flaring activity by recording a vast amount of super-flares from solar-like stars, as well as detecting flares from hotter stars of A-F spectral types. Currently, we know that flaring occurs in the stars as hot as B-type ones. However, the struct…
Large-Scale Ejecta of Z CMa—Proper Motion Study and New Features Discovered
Liimets, Tiina; Kraus, Michaela; Cidale, Lydia +2 more
Z Canis Majoris is a fascinating early-type binary with a Herbig Be primary and a FU Orionis-type secondary. Both of the stars exhibit sub-arcsecond jet-like ejecta. In addition, the primary is associated with the extended jet as well as with the large-scale outflow. In this study, we investigate further the nature of the large-scale outflow, whic…
New Insight into the FS CMa System MWC 645 from Near-Infrared and Optical Spectroscopy
Kraus, Michaela; Arias, María Laura; Eenmäe, Tõnis +2 more
The B[e] phenomenon is manifested by a heterogeneous group of stars surrounded by gaseous and dusty circumstellar envelopes with similar physical conditions. Among these stars, the FS CMa-type objects are suspected to be binary systems, which could be experiencing or have undergone a mass-transfer process that could explain the large amount of mat…