The Greek poet Sappho was so prolific that she remained celebrated centuries after her death. Experts, however, know little about her life except that she was born in and died on the island of Lesbos.

Experts thought that the female poet, who closely rivaled Homer, was born sometime between 630 and 612 BCE and died around 670 BCE after she returned from exile.

Researchers from the the University of Texas at Arlington, however, were able to ascertain that Sappho was alive until at least 570 BCE, thanks to a fragment of her "Midnight Poem," one of about 200 fragments of the poet's work that still survive today.

In a new study published in the Journal of Astronomical History and Heritage, researchers have found that the work, which was written for an absent lover, was written in the mid-sixth century BCE.

"Midnight Poem" describes a star cluster called the Pleiades, also known as the Seven Sisters, setting at midnight.

Scholars have long debated on when this poem was written but using a software that simulates night skies in planetariums, researchers appear to have finally determined the age of this ancient Greek poem.

Physics professor Manfred Cuntz, from the University of Texas at Arlington and colleagues used the software Starry Night version 7.3 to recreate the night sky in 570 BCE as seen from Lesbos.

The researchers found that the Pleiades set at midnight on Jan. 25 and as the year progressed, set earlier until March 31, which would be the latest date it could have been visible in the dark sky.

"We also identified the latest date on which the Pleiades would have been visible to Sappho from that location on different dates some time during the evening," Cuntz said. "From there, we were able to accurately seasonally date this poem to mid-winter and early spring."

The researchers acknowledged that the choice of the year 570 BCE was an arbitrary decision but the movement of the Pleiades changed very little every year to somebody from Lesbos watching the sky.

"Because Lesbos is relatively small and the same phenomena repeat almost exactly from year to year on a given date, altering the observing location to nearby Eressos, or the year of observation by as much as 40 years, made very little difference," the researchers wrote.

Sappho is known to mention cosmological landmarks in her poems but by specifically mentioning the Pleiades in "Midnight Poem," the poet provided researchers with a handy temporal point to date the time when this particular piece was written.