Stellar evolution before the ZAMS

Stellar evolution before the ZAMS

Young stars on their way to the ZAMS evolve in significantly different ways depending on their mass. While the theoretical and observational properties of lowand intermediate-mass stars are rather well understood and/or empirically tested, the situation for massive stars (> ∼ 10– 15 M⊙) is, to say the least, still elusive. On theoretical grounds, the PMS evolution of these objects should be ext...

It’s Ez to Evolve Zams Stars: a Program Derived from Eggleton’s Stellar Evolution Code

“Evolve ZAMS”, “EZ” for short, is derived from Peter Eggleton’s stellar evolution program. The core of EZ is a stripped down, rewritten version of a subset of Eggleton’s code, specialized to handle single star evolution from the zero-age main sequence until forced to stop by an event such as a helium flash or a crystallizing core. The procedure and data interfaces to the program are designed to...

Stellar Structure and Evolution

Stellar Evolution Presenting

Stars “evolve” with time in a predicable manner. Our theory of stellar evolution is one of the foundations of astrophysics, is well tested and verified, and has enabled great advances in many fields of astrophysics. As such, stellar evolution is a cornerstone of any astronomy course, from the 100 level up through graduate levels. One of the leading software to model a star’s evolution in detail...

Horizontal Branch Stellar Evolution

I review aspects of the evolution of horizontal branch (HB) stars. The defining characteristic of this, the core He-burning phase of evolution for M < Mflash ∼ 2.2M⊙, is a spread in observed colour amongst HB stars within the (almost) chemically homogeneous, isochronous populations found in Galactic globular clusters. The inference is that the stars within a given cluster must have undergone va...