How did scientists determine SM0313 is the oldest star ever discovered?

The star sm0313, was discovered using the ANU skymapper telescope at the siding spring observatory and later confirmed by the megellan telescope in Chile. Somewhat surprisingly, it's located a "mere" 6,000 thousand light-years away, they origins date back to the beginning of time.

-It was discovered using the ANU skymapper telescope. Scientists found that it is a good 6,000 lightyears away, dating back to the beginning of time.

Explanation:

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