Related papers: Instabilities in Interacting Binary Stars
It is well known that magnetic activity in late-type stars increases with increasing rotation rate. Using inversion techniques akin to medical imaging, the rotationally broadened profiles from such stars can be used to reconstruct `Doppler…
In an effort to better understand the details of the stellar structure and evolution of metal poor stars, the Gemini North telescope was used on two occasions to take speckle imaging data of a sample of known spectroscopic binary stars and…
We investigate the pulsational properties of Pre--Main-Sequence (PMS) stars by means of linear and nonlinear calculations. The equilibrium models were taken from models evolved from the protostellar birthline to the ZAMS for masses in the…
Stars exhibit a bewildering variety of rapidly variable behaviors ranging from explosive magnetic flares to stochastically changing accretion to periodic pulsations or rotation. The principal Rubin Observatory Legacy Survey of Space and…
Previous studies on the rotation of Sun-like stars revealed that the rotational rates of young stars converge towards a well-defined evolution that follows a power-law decay. It seems, however, that some binary stars do not obey this…
We analyse public domain time-series photometric observations of 30 known and candidate binary post-AGB stars for measuring pulsation and orbital periods. We derive periodicities for 17 stars for the first time in the literature. Besides…
Previous work indicates that about 10% of planetary-nebula nuclei (PNNi) are photometrically variable short-period binaries with periods of hours to a few days. These systems have most likely descended from common-envelope (CE) interactions…
We continue here the systematic abundance analysis of a sample of Am binaries in order to search for possible abundance anomalies driven by tidal interaction in these binary systems. New CCD observations in two spectral regions (6400-6500,…
In the course of our search for double degenerate binaries as potential progenitors of type Ia supernovae with the UVES spectrograph at the ESO VLT (ESO SN Ia Progenitor surveY - SPY) we discovered that the sdB star HE 1047-0436 is radial…
We have conducted a deep photometric survey of a 0.5 deg x 0.5 deg area of the Galactic Plane using the WFI instrument on the 2.2-m ESO telescope on La Silla, Chile. The dataset comprises a total of 267 R-band images, 204 from a 16 day…
Shaping axi-symmetric planetary nebulae is easier if a companion interacts with a primary at the top of the asymptotic giant branch. To determine the impact of binarity on planetary nebula formation and shaping, we need to determine the…
We have identified some two-hundred new variable stars in a systematic study of a data archive obtained with the Calvin-Rehoboth observatory. Of these, we present five close binaries showing behaviors presumably due to star spots or other…
We present a stability analysis of a large set of simulated planetary systems of three or more planets based on architectures of multiplanet systems discovered by \textit{Kepler} and \textit{K2}. We propagated 21,400 simulated planetary…
The rich absorption spectra of Sun-like stars are enticing probes for variations in the fine-structure constant, $\alpha$, which gauges the strength of electromagnetism. While individual line wavelengths are sensitive to $\alpha$, they are…
Binary interactions are commonplace among massive stars, giving rise observed phenomena such as X-ray binaries, stripped stars & supernovae, and gravitational-wave sources. The multiplicity properties of massive stars thus represent a…
We study the stability properties of isolated star forming dwarf galaxies which undergo dynamically driven starbursts induced by stellar feedback. Here we focus on the impact of the adopted ISM model, i.e. either a diffuse or a clumpy ISM.…
Radial-velocity measurements and sine-curve fits to the orbital velocity variations are presented for nine contact binaries, V1464 Aql, V759 Cen, DE Oct, MW Pav, BQ Phe, EL Aqr, SX Crv, VZ Lib, GR Vir; for the first five among these, our…
Despite being the most abundant (by space density) of interacting binary stars, W Ursae Majoris (W UMa) stars are not understood structurally. Their stellar components are in physical contact, and share a common convective envelope.…
We have compiled the first all-sky mid-infrared variable-star catalog based on Wide-field Infrared Survey Explorer (WISE) five-year survey data. Requiring more than 100 detections for a given object, 50,282 carefully and robustly selected…
Hydrodynamical simulations of semi-detached, polytropic binary stars are presented in an effort to study the onset and stability of dynamical mass transfer events. Initial, synchronously rotating equilibrium models are constructed using a…