Scientists Explain Death Dance and Explosion of Binary Star Systems

Recent studies have shown that certain stars do not die alone, which may clarify the mystery surrounding a specific type of cosmic explosion known as the interacting supernova. When stars with masses significantly exceeding that of the Sun reach the end of their life cycles, their cores collapse, releasing shock waves that propagate through their outer layers. This process results in supernova explosions and leaves behind stellar remnants such as neutron stars or black holes.

According to Space, most stars exist not in isolation but within binary systems bound by gravity. The new research suggests these stars not only coexist but can also die simultaneously. Understanding this dual existence could be crucial to explaining the origins of dust shells observed in interacting supernovae.

Kei-Jong Chen, a team member from the Institute of Astronomy and Astrophysics at Academia Sinica (ASIAA), stated, "Our study indicates that many stars do not die alone; their final appearance may be shaped by a long and close relationship with a companion star."

How Do Some Stars Become Energy-Draining?

Before stars reach the end of their lives, they enter a relatively brief red giant phase during which they can expand to hundreds or even thousands of times their original radius. In binary star systems, this expansion leads to a phenomenon called Roche lobe overflow, where the enlarged star transfers material onto its companion. However, the companion star does not capture all the transferred material; some of it escapes and forms an extensive envelope surrounding the binary pair.

When the evolved and expanded star eventually explodes as a supernova, the shock waves move outward and collide with this surrounding material at speeds of thousands of miles per second. The kinetic energy from this collision converts into light, producing a highly luminous interacting supernova.

What Determines the Formation of Interacting Supernovae?

Chen and his colleagues conducted hundreds of computer simulations modeling mass transfer between binary stars. Their findings reveal that the timing of mass transfer during the late stages of stellar evolution is critical to generating an interacting supernova.