The Chandrasekhar limit for quark stars

The Chandrasekhar limit for quark stars is evaluated from simple energy balance relations, as proposed by Landau for white dwarfs or neutron stars. It has been found that the limit for quark stars depends on, in addition to the fundamental constants, the Bag constant. Compact objects like the white dwarfs and neutron stars have been a topic of interest for several decades. These objects are produced as the end product of the stellar evolution, i.e. , when the nuclear fuel of the normal stars have been consumed. White dwarfs are supported against gravitational collapse by the degeneracy pressure of electrons whereas for neutron stars, this pressure comes mainly from the degenerate neutrons. It is well known that both these classes of collapsed stars have a maximum mass ( ∼ 1.5M⊙ ), beyond which they collapse to black holes [1, 2, 3]. Although the Chandrasekhar limit refers strictly to white dwarfs, the limiting mass for neutron stars is also loosely called the Chandrasekhar limit, primarily because the limits in the two cases turn out to be the same [2]. The underlying quark structure of the nucleons suggests a possible hadron quark phase transition at high density and/or temperature. This, in turn, implies the possible existence of another kind of compact objects, namely quark stars [4, 5, 6]. The suggestion of Witten[7] that the strange quark matter may be the true ground state of the strongly interacting matter started a new era in this subject. In this circumstance, quark stars, if they are formed, would preferably convert to strange stars, comprising u, d and s quarks, under weak interaction. Several authors ( for example, [8, 9] ) have used different models to understand the properties of strange stars. For a review, see [6]. The unique feature of strange stars, which separates them from other compact objects, is that these need not be the direct product of stellar evolution. These are most likely to be produced due to the hadron quark phase email: [email protected] email: [email protected] email: [email protected]