Stellar Evolution and Galactic Evolution

The Stellar Imf of Galactic Clusters and Its Evolution

We show that one can obtain a good fit to the measured main sequence mass function (MF) of a large sample of Galactic clusters (young and old) with a tapered Salpeter power law distribution function with an exponential truncation. The average value of the power law index is very close to Salpeter (∼ 2.3), whereas the characteristic mass is in the range 0.1− 0.5M⊙ and does not seem to vary in a ...

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...

FUors and Early Stellar Evolution

Ambartsumian was among the first researchers who recognized the importance and uniqueness of FUors, the term he coined for the rare outburst sources of the FU Orionis type. A wealth of observational data and concomitant theoretical work has advanced our understanding of FUors in the intervening almost 40 years. These results are summarized in this brief review, with special emphasis on observat...