Sunday April 14, 2024

On this dead star, a single day equals to 72 Earth years

Dead star rich in carbon, oxygen rushes so fast that its one day equates to 72 Earth years

By Web Desk
February 19, 2024
An illustration shows the TMTS J0526 binary star system. — Jingchuan Yu/Beijing Planetarium/File
An illustration shows the TMTS J0526 binary star system. — Jingchuan Yu/Beijing Planetarium/File

In an amazing binary system that astronomers have found, a "dead star," or white dwarf, rushes around its minuscule and scorching stellar partner so quickly that it compresses about 72 Earth years into a single day.

Using the Tsinghua University-Ma Huateng Telescope for Survey (TMTS), a team from Tsinghua University discovered the system, which they named TMTS J0526. It is situated approximately 2,760 light-years away from Earth, according to Space.

A white dwarf star rich in carbon and oxygen, with a mass of around 74% of the Sun's, can be found at TMTS J0526. It orbits a hot subdwarf star that is about seven times as wide as Earth and has a mass around a third that of our star. In terms of volume, it is smaller than Jupiter, the gas giant planet, and among the tiniest stars ever observed.

Each orbit is completed by the parts of TMTS J0526 approximately every 20.5 minutes. Though the system is still inferior to HM Cancri, which has two white dwarfs that complete an orbit roughly every 5.4 minutes, this makes it a record-breaker for this kind of binary.

Still, compared to its white dwarf companion, the little star is bigger and more apparent due to its thin hydrogen atmosphere. However, when the two swiftly orbit one another, the white dwarf's strong gravitational pull can bend the tiny star into an ellipsoid shape.

Furthermore, TMTS J0526's finding is noteworthy not just for its extraordinarily brief orbital period but also because it may provide light on the process by which such minuscule subdwarf stars form in the first place.

When sun-sized stars run out of hydrogen in their cores and are unable to sustain themselves against the pull of gravity from within, white dwarfs are formed.

As a result, the outer layers of the stars, where nuclear fusion is still occurring, spread outward and the collapse of the stellar core. The stars undergo an initial transformation into red giants, followed by a cooling process that leaves behind white dwarfs encircled by gas and dust envelopes.