Supernovae: The Stellar Route to Understanding Dark Energy

Part 3: Issues Facing Type Ia Supernova Cosmology

The final installment of a series reporting on the Supernova Workshop sponsored by SNAP, the SuperNova/Acceleration Probe collaboration, to investigate the best ways to study dark energy with exploding stars.

Supernova cosmology was founded on measurements of distant Type Ia supernovae, and high-z searches for distant supernovae have continued to multiply, using both ground-based telescopes and the Hubble Space Telescope. (Z stands for redshift.)

All these searches share the goal of narrowing constraints on possible theories of dark energy by narrowing the allowable values of w, the dark energy "equation of state," the ratio between its pressure and energy density.

At the Supernova Workshop Isobel Hook reported, by conference call from England, on a recent report from the Supernova Cosmology Project. After performing several comparisons of high-z and low-z supernovae in a group of 14 Type Ia's, the authors concluded that there are no significant differences among them — or, stated more conservatively, that "there is a sample of high-z Ia's whose properties match those of low-z Ia's." ...


Click here to read the rest of this news story and the earlier Parts 1 & 2.