London, United Kingdom – A groundbreaking discovery has been made about the fate of a binary star system located approximately 150 light-years away from Earth. For the two white dwarf stars in this system, a precise time of death has been revealed – they are destined to collide in a spectacular explosion known as a Type Ia supernova in around 23 billion years.
Scientists have long suspected that white dwarf stars are responsible for Type Ia supernovae that light up the sky, but this recent finding confirms a theoretical prediction. It suggests that the precursor to most Type Ia supernovae involves two white dwarf stars in a binary system, rather than just one.
These white dwarfs are not living stars in the traditional sense, as they are no longer fusing hydrogen in their cores like main sequence stars. When the hydrogen runs out, the star dies, leaving behind a white dwarf – an ultradense object with a mass up to 1.4 times that of the Sun compressed into a small space between the sizes of Earth and the Moon.
The Type Ia supernova that occurs when a white dwarf exceeds its mass limit is crucial for seeding the Universe with heavy elements. These explosions are also valuable for measuring distances in space due to their known specific brightness peak.
The discovery of a binary white dwarf system known as WDJ181058.67+311940.94 provides concrete evidence linking Type Ia supernovae to white dwarf binaries. This system, with a combined mass equal to 1.56 times that of the Sun, is expected to produce a Type Ia supernova in around 23 billion years as the two stars gradually draw closer together.
This finding offers new insights into the origins of Type Ia supernovae and sheds light on what to look for in the search for similar systems in the Milky Way galaxy. It represents a monumental leap in our understanding of the life cycles of stars and the processes that shape the cosmos.
The research detailing this discovery has been published in the prestigious journal Nature Astronomy, marking a significant milestone in the field of astrophysics. This breakthrough opens up exciting new avenues for studying the interactions between binary stars and the cosmic events that shape our Universe.