Search Publications
Self-consistent modelling of the Milky Way structure using live potentials
Klessen, Ralf S.; Sormani, Mattia C.; Smith, Rowan J. +6 more
To advance our understanding of the evolution of the interstellar medium (ISM) of our Galaxy, numerical models of Milky Way (MW) type galaxies are widely used. However, most models only vaguely resemble the MW (e.g. in total mass), and often use imposed analytic potentials (which cannot evolve dynamically). This poses a problem in asserting their …
HD 34736: an intensely magnetised double-lined spectroscopic binary with rapidly rotating chemically peculiar B-type components
Shulyak, D.; Wade, G. A.; Zejda, M. +21 more
We report the results of a comprehensive study of the spectroscopic binary (SB2) system HD 34736 hosting two chemically peculiar (CP) late B-type stars. Using new and archival observational data, we characterize the system and its components, including their rotation and magnetic fields. Fitting of the radial velocities yields
Seismic and spectroscopic analysis of nine bright red giants observed by Kepler
Valle, G.; Dell'Omodarme, M.; Prada Moroni, P. G. +21 more
Photometric time series gathered by space telescopes such as CoRoT and Kepler allow to detect solar-like oscillations in red giant stars and to measure their global seismic constraints, which can be used to infer global stellar properties (e.g. masses, radii, and evolutionary states). Combining such precise constraints with photospheric abundances…
Chandra and HST studies of the X-ray sources in the globular cluster NGC 362
Heinke, Craig O.; Cohn, Haldan N.; Lugger, Phyllis M. +1 more
We analyse a Chandra observation of the rich globular cluster NGC 362, finding 33 X-ray sources within 1 arcmin (1.2 half-mass radii) of the cluster centre. Spectral analysis of the brightest source (X1) shows blackbody-like emission, indicating it is likely a quiescent low-mass X-ray binary; we find a possible counterpart that falls in the sub-su…
Chandra/HETG Doppler velocity measurements in stellar coronal sources
de Plaa, J.; Costantini, E.; Paltani, S. +4 more
Stellar coronal sources have been observed in the past not only for their astrophysical interest in the field of binary system evolution and interaction but also for their invaluable roles as benchmarks for plasma spectral models and as calibration sources for high resolution spectroscopic X-ray instruments. These include the gratings on-board Cha…
Benchmarking the spectroscopic masses of 249 evolved stars using asteroseismology with TESS
Huber, Daniel; Bedding, Timothy R.; Stello, Dennis +5 more
One way to understand planet formation is through studying the correlations between planet occurrence rates and stellar mass. However, measuring stellar mass in the red giant regime is very difficult. In particular, the spectroscopic masses of certain evolved stars, often referred to as 'retired A-stars', have been questioned in the literature. Ef…
Light curves for 10 R Coronae Borealis stars for longer than a century: secular evolution, dip statistics, and a general model for the shape of isolated light-curve dips
Schaefer, Bradley E.
R Coronae Borealis stars (RCBs) are cool supergiants that display non-periodic deep dips in brightness. Recently, a group of 'Hot RCB stars' has been discovered to be fast evolving across the HR (Hertzsprung-Russell) diagram, as these stars leave the RCB region, with brightness changes at the rate of ~1 mag per century. Perhaps cool RCB stars can …
Orbits and dynamical masses for the active Hyades multiple system HD 284163
Torres, Guillermo; Latham, David W.; Monnier, John D. +16 more
We report near-infrared long-baseline interferometric observations of the Hyades multiple system HD 284163, made with the Center for High Angular Resolution Astronomy array, as well as almost 43 yr of high-resolution spectroscopic monitoring at the Center for Astrophysics. Both types of observations resolve the 2.39 d inner binary, and also an out…
Probing solar wind velocity from simultaneous superior solar conjunction radio science experiments of BepiColombo and Akatsuki missions
Imamura, T.; Shiota, D.; Iess, L. +5 more
A radio link directly probing the inner solar corona offers the possibility to characterize solar wind properties, including velocity, density, turbulence, and even the axial ratio. In this study, we leveraged radiometric data obtained during a joint superior solar conjunction of the ESA/JAXA BepiColombo mission and the JAXA Akatsuki mission. Our …
Exploring the ex-situ components within Gaia DR3
Zhao, Gang; Chen, Yuqin; Xue, Xiang-Xiang +3 more
The presence of Gaia DR3 provides a large sample of stars with complete 6D information, offering a fertile ground for the exploration of stellar objects that were accreted to the Milky Way through ancient merger events. In this study, we developed a deep learning methodology to identify ex-situ stars within the Gaia DR3 catalogue. After two phases…