October 17, 2007

Aging Galaxy Is "Unique" Researchers Say

I Zwiky 18 looks like a typically young galaxy. However, the more researchers research this particular object, the older it appears to get.

Researchers have now located faint, older stars in the center of the galaxy that have proven researchers wrong... twice. The older stars show that initial estimates of its distance were off by more than ten million light years by measuring the light from these older stars.

It also proved researchers wrong because it showed that the galaxy is quite a bit older than initially thought. By dating the fainter, older stars, we find out that this galaxy formed at the same time other galaxies formed. However, the appearance of the galaxy is that of a younger universe.

The main components of this galaxy are hydrogen and helium, which suggests it was around near the beginning of time after the Big Bang. However, the reason that this galaxy still produces far less stars than its peers still eludes researchers.

"...it is certainly developmentally challenged and unique in the nearby universe," said astronomer Alessandra Aloisi from the Space Telescope Science Institute and the European Space Agency, who led the study.