Born On 3 Different Days?

Astrologers argue endlessly about different birth times. Maybe they're all correct. Found an interesting article from HubbleSite.org called "What's My Age? Mystery Star Cluster Has 3 Different Birthdays." Scientists are trying to understand how the Stars in a certain cluster seem to have been born at 3 different times.

Imagine having three clocks in your house, each chiming at a different time. Astronomers have found the equivalent of three out-of-sync "clocks" in the ancient open star cluster NGC 6791. The dilemma may fundamentally challenge the way astronomers estimate cluster ages, researchers said.

Using NASA's Hubble Space Telescope to study the dimmest stars in the cluster, astronomers uncovered three different age groups. Two of the populations are burned-out stars called white dwarfs. One group of these low-wattage stellar remnants appears to be 6 billion years old, another appears to be 4 billion years old. The ages are out of sync with those of the cluster's normal stars, which are 8 billion years old.

"The age discrepancy is a problem because stars in an open cluster should be the same age. They form at the same time within a large cloud of interstellar dust and gas. So we were really puzzled about what was going on," explained astronomer Luigi Bedin, who works at the Space Telescope Science Institute in Baltimore, Md.

http://hubblesite.org/newscenter/archive/releases/2008/25/full/