The energy balance in contact binaries
نویسنده
چکیده
We derive the global energy balance in contact binaries evolving on a thermal time-scale, including the semidetached phase. Effects of accretion and rotation are taken into account. Within the framework of standard assumptions (uniform rotation, conservation of mass and angular momentum, spherically averaged components, each of them in hydrostatic equilibrium) the discussion is exact.
منابع مشابه
Structure and evolution of low mass W UMa type systems
The structure and evolution of low-mass W UMa type contact binaries are discussed by employing Eggleton’s stellar evolution code (Eggleton 1971, 1972, 1973). Assuming that these systems completely satisfy Roche geometry, for contact binaries with every kind of mass ratios (0.02∼1.0), we calculate the relative radii (R1,2/A, where R1,2 are the radii of both stars, and A the orbital separation) o...
متن کاملContact Binaries
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. Observations demand large-scale energy exchange between components, as do considerations of hydrostatic and thermal equilibrium. Yet solutions in complete equilibri...
متن کاملAngular momentum and mass evolution of contact binaries
Various scenarios of contact binary evolution have been proposed in the past, giving hints of (sometimes contradictory) evolutionary sequence connecting A-type and W-type systems. As the components of close detached binaries approach each other and contact binaries are formed, following evolutionary paths transform them into systems of two categories: A-type and W-type. The systems evolve in a ...
متن کاملThe Comparison of the Difference in Foot Pressure, Ground Reaction Force, and Balance Ability According to the Foot Arch Height in Young Adults
Background. Human feet have important roles in supporting, moving and balancing the body. The feet must not only support the weight of the body but must also have the elasticity to absorb the burden associated with supporting excessive body weight. Objectives. The purpose of this study was to compare the difference of foot pressure, ground reaction force, and balance ability according to chang...
متن کاملForty Years of X-Ray Binaries
In 2012 it was forty years ago that the discovery of the first X-ray binary Centaurus X-3 became known. That same year it was discovered that apart from the High-Mass X-ray Binaries (HMXBs) there are also Low-Mass X-ray Binaries (LMXBs), and that Cygnus X-1 is most probably a black hole. By 1975 also the new class of Be/X-ray binaries was discovered. After this it took 28 years before ESAs INTE...
متن کامل