Thought folks might find this interesting... Didn't see it yet posted.

('Secondary' method of measuring distance to galaxies stronger than previously thought)
http://economictimes.indiatimes.com/ET_Cetera/Secondary_measure_of_galaxy_distance/articleshow/3540404.cms

Australian and US scientists have found that a 'secondary' method of measuring the distance to nearby galaxies is more robust than previously thought.

They found these stars to be just as good, if not better than Cepheids ... For nearby distances, Cepheid variables - bright stars that expand and contract by 10 percent - have long been the primary 'standard candles' used.

But, some astronomers have recently cast suspicion on the capacity of Cepheids as standard candles, according to Mould. "The question has been whether the relationship is more complicated than we think. Things like the composition of the star may make a difference," said Mould.

Towards the end of their life, red giants produce a flash as they exhaust their outer hydrogen shell and begin to burn helium from their core. The luminosity of the flash is well understood and therefore the stars make good standard candles.

But unlike the Cepheid variables, the red giant flash isn't influenced by the star's age or composition, the researchers said. "It looks like this alternative standard candle is immune to things like differences in the chemical composition of stars," said Mould. "It confirms the Cepheid variable scale using a completely independent technique," he added.

According to Dr Scott Croom of the University of Sydney, the TRGB technique, which is a well understood idea, is potentially more robust that the Cepheid variable technique.