A visual search has been made of four fields using United Kingdom 1.2m Schmidt Objective Prism plates with a reciprocal dispersion of 1 180 A/mm at HP. Such plate material is ideally suited to searches for emission-line galaxies. We present a catalogue of 53 emission-line objects, which comprises 45 galaxies, where individual HI1 regions are resolved in 16 bright galaxies; 8 are emission li...

The importance of stellar encounters in producing stellar exotica in dense stellar clusters is reviewed. We discuss how collisions between main–sequence stars may be responsible for the production of blue stragglers in globular clusters. We also discuss the possible pathways to the production of X–ray binaries, cataclysmic variables, and millisecond pulsars in globular clusters. Neutron stars i...

The single star-stellar population (ss-SSP) models are usually used for stellar population studies. However, there are more than 50% stars that are in binaries and evolve differently from single stars. This suggests when we model the stellar populations of galaxies and star clusters, the effects of binary interactions should be considered. Although a few works tried to model stellar populations...

A variety of magnetohydrodynamic mechanisms that may play a role in magnetic, chemically peculiar (mCP) stars is reviewed. These involve dynamo mechanisms in laminar flows as well as turbulent environments, and magnetic instabilities of poloidal and toroidal fields as well as combinations of the two. While the proto-stellar phase makes the survival of primordial fields difficult, the variety of...

Context. The young binary system V773 Tau A exhibits a persistent radio flaring activity that gradually increases from a level of a few mJy at apoastron to more than 100 mJy at periastron. Interbinary collisions between very large (>15 R∗) magnetic structures anchored on the two rotating stars of the system have been proposed to be the origin of these periodic radio flares. Magnetic structures ...

Abstract Gravitational decoupled compact polytropic hybrid stars are here addressed in generalized Horndeski scalar-tensor gravity. Additional physical properties of scrutinized and discussed the gravitational decoupling setup. The asymptotic value mass function, compactness, effective radius studied for both cases a bosonic fermionic prevalent core. These quantities presented as functions para...

Using the fluid-magnetofluid formalism, we obtain axisymmetric stability criteria for a composite disc system consisting of stellar and gaseous magnetized singular isothermal discs (MSIDs). Both (M)SIDs are presumed to be razor-thin and are gravitationally coupled in a self-consistent axisymmetric background equilibrium with power-law surface mass densities and flat rotation curves. The gaseous...