Related papers: Properties of the $\delta$ Scorpii Circumstellar D…
Classical Be stars are hot non-supergiant stars surrounded by a gaseous circumstellar disk that is responsible for the observed infrared (IR) excess and emission lines. The influence of binarity on these phenomena remains controversial. We…
We acquired Johnson BV photometry of the binary Be disk system delta~Scorpii during its 2009, 2010, 2011, and 2012 observing seasons and used it to probe the innermost regions of the disk. We found that several disk building events have…
We present infrared photometric observations of the Be binary system delta Scorpii obtained in 2006. The J,H and K magnitudes are the same within the errors compared to observations taken 10 months earlier. We derive the infrared excess…
The binary star delta Sco (HD143275) underwent remarkable brightening in the visible in 2000, and continues to be irregularly variable. The system was observed with the Sydney University Stellar Interferometer (SUSI) in 1999, 2000, 2001,…
The Be star \delta\ Scorpii is an interesting binary system, whose primary companion created a circumstellar disk after the periastron passage of the secondary in 2000, being since then classified as Be. This work presents the results of a…
The bright star delta Sco has been considered a typical B0-type object for many years. Spectra of the star published prior to 1990 showed no evidence of emission, but only of short-term line profile variations attributed to nonradial…
We model the circumstellar disk of $\delta$ Sco using the 3-dimensional Monte Carlo radiative transfer code HDUST in order to quantify the large scale changes in the disk through the years 2000 to 2018, and to see if these changes can be…
Classical Be stars are hot non-supergiant stars surrounded by a gaseous circumstellar disk that is responsible for the observed IR-excess and emission lines. The influence of binarity on these phenomena remains controversial. delta Sco is a…
We examine the evolution of the disk surrounding the Be star in the highly eccentric binary system $\delta$ Scorpii over its three most recent periastron passages. $V$-band and $B-V$ photometry, along with H$\alpha$ spectroscopy are…
Belonging to the group of B[e] stars, V921 Scorpii is associated with a strong infrared excess and permitted and forbidden line emission, indicating the presence of low- and high-density circumstellar gas and dust. Many aspects of V921 Sco…
We present ALMA Band 7 continuum (340 GHz) and CO J=3-2 observations for an extended sample of disks in the Upper Scorpius OB Association (Upper Sco, age ~ 10 Myr). The targets were selected from previous studies that identified new members…
We present near-infrared H and K-band spectro-interferometric observations of the gaseous disk around the primary Be star in the delta Sco binary system, obtained in 2007 (between periastron passages in 2000 and 2011). Observations using…
V921 Scorpii is a close binary system (separation 0.025") showing the B[e]-phenomenon. The system is surrounded by an enigmatic bipolar nebula, which might have been shaped by episodic mass-loss events, possibly triggered by dynamical…
The first two of a total of six nano-satellites that will constitute the BRITE-Constellation space photometry mission have recently been launched successfully. In preparation for this project, we carried out time-resolved colour photometry…
We modelled optical light curves of Sco~X-1 obtained by the Kepler space telescope during K2 mission. Modelling was performed for the case of the strong heating of the optical star and accretion disc by X-rays. In the considered model the…
Context: Both the absolute mass-loss rates and the mechanisms that drive the mass loss of late-type supergiants are still not well known. Binaries such as alpha Sco provide the most detailed empirical information about the winds of these…
We present high resolution near-infrared spectra of $\beta$ Pictoris - a nearby young star with a debris disk. Fundamental low-J CO absorption lines are detected and strict upper limits are placed on the flux of v=2-1 low-J CO emission…
The model of an young star with a protoplanetary disk and a low-mass companion, which is moving on a circular orbit, inclined to the disk plane, is considered. The hydrodynamic models of such a system were calculated by SPH method. It was…
The observed emission lines of Be stars originate from a circumstellar Keplerian disk that are generally well explained by the Viscous Decretion Disk model. In an earlier work we performed the modeling of the full light curve of the bright…
We present self-consistent solutions for the disk structure of classical Be stars. Our disk model is hydrostatically supported in the vertical direction and the radial structure is governed by viscosity ($\alpha$-disks). We perform…