Saturday, January 22

Astronomers Unlock the Interior Structure of Beta Crucis – Reveal the Age of Massive Southern Cross Star

Astronomers Unlock the Interior Structure of Beta Crucis – Reveal the Age of Massive Southern Cross Star

Southern Cross

Southern Cross (view from Merna Mora, South Australia). Credit: James St. John (CC BY 2.0)

An international team of astronomers from Australia, the United States, and Europe has for the first time unlocked the interior structure of Beta Crucis – a bright blue giant star that features on the flags of Australia, Brazil, New Zealand, Papua New Guinea, and Samoa.

With an entirely new approach, the team led by Dr. Daniel Cotton, found the star to be 14.5 times as massive as the Sun and as young as 11 million years old, making it the heaviest star with an age determined from asteroseismology ever.

The findings will provide new detail on how stars live and die, and how they impact the Galaxy’s chemical evolution.

To crack the star’s age and mass, the research team combined asteroseismology, the study of a star’s regular movements, with polarimetry, the measurement of the orientation of light waves.

Asteroseismology relies on seismic waves bouncing around the interior of a star and producing measurable changes in its light. Probing the interiors of heavy stars that will later explode as supernovae has traditionally been difficult.

Southern Cross Over Chilean Volcano

Southern Cross over Chilean Volcano. This famous four-star icon is best seen from Earth’s Southern Hemisphere. This image was taken in Chile and captures the Southern Cross just to the left of erupting Villarrica, one of the most active volcanos in our Solar System. Credit & Copyright: Tomáš Slovinský

“I wanted to investigate an old idea,” lead author Dr. Cotton, from The