Three binary systems in the Hyades open cluster (51 Tau, V818 Tau, and θ2 Tau), with known metallicity and good Johnson photometric data are used to test the validity of three independent sets of stellar evolutionary tracks. A statistical method is described and applied to the colour-magnitude diagram of the six selected components, giving rise to χ2-contours in the metallicity–age plane. The e...

Two cylindrical forward TPC detectors are described which were constructed to extend the phase space coverage of the STAR experiment to the region 2.5 < |η| < 4.0. For optimal use of the available space and in order to cope with the high track density of central Au+Au collisions at RHIC, a novel design was developed using radial drift in a low diffusion gas. From prototype measurements a 2-trac...

This paper presents a satellite tracking method based on optical celestial images. The proposed method is composed of two acquiring modes that are called Sidereal Stare Mode (SSM) and Track Rate Mode (TRM). To track the unknown satellites, first of all the entire of the sky is observed and the primary knowledge of the satellite location is predicted in SSM. Then, the measured pointing data is c...

We present new evolutionary sequences for long lasting accreting low-mass (0.1 M ≤ M ≤ 2.5M ) pre-main sequence stars. The calculations, performed for two different mass accretion rates, show that accretion accelerates the evolution of the star. The star has a smaller radius and goes down its convective track faster than in a standard scheme. Consequently, the age of a star, as given by its loc...

We describe new optical photometric and spectroscopic observations of the semidetached eclipsing binary BG Geminorum. A large change in the amount of Mg I absorption at secondary maximum indicates the presence of cool material in the outer edge of the disk surrounding the unseen primary star. Detection of weak He I emission implies a hot radiation source at the inner edge of the disk. If the ve...

car body acceleration is an important factor affecting track safety and ride comfort, which are two primary aspects of railway systems. though track level is an important source of wagon body acceleration, no quantitative relation between them is available and the aim of this paper is to propose a method to address this issue. to do so, car body acceleration is determined using a 10 dof simulat...

star identification is one of the most important stages in attitude determination with star trackers. this can be performed using matching algorithms between observed stars and a master star catalogue. the main challenge in this approach is to provide a fast and reliable identification algorithm that is sufficiently robust in different pointing views of the star tracker optical system in the sp...