Some ‘twin’ stars eat planets, according to a new study

Over the course of its nearly 4.5 billion years of existence, the planetary system that consists of Earth and its sister planets orbiting the sun has remained highly stable. However, a recent study involving “twin” stars demonstrates that not all planetary systems are as fortunate.

Scientists reported on Wednesday that an incredible number of pairs of stars with similar diameters and chemical compositions have evidence of having swallowed a planet, most likely after the planet got out of a stable orbit for a variety of causes.

The study examined pairs of stars, referred to as co-natal stars, that formed in the same interstellar cloud of gas and dust, giving them a similar chemical composition and about similar mass and age. This group are the “twins.” The pairings are not binary systems of two stars gravitationally bonded to one other, even if they are traveling in the same direction within our Milky Way galaxy.

When a star consumes a planet, the elements that comprised the unfortunate globe are incorporated into the star’s composition, changing it physically. In comparison to some other elements, the researchers searched for stars that were different from their twin because they included larger concentrations of indicators of rocky planet remains, such as iron, nickel, or titanium.

“It’s the differences in elemental abundance between two stars in a co-natal system,” explained lead scientist and astronomer Fan Liu of Australia’s Monash University, which published the study in the journal.

One of the two stars in seven of the pairs showed signs of planetary ingestion.

The researchers believed that a planet may fall to its death due to an orbital disruption from a larger planet or an uncomfortably close visit by another star that would destabilize the planetary system.

Astrophysicist and study co-author Yuan-Sen Ting of the Australian National University and Ohio State University remarked, “This really puts into perspective our fortuitous position in the universe.” “The stability of a planetary system like the solar system is not a given.”

The twins were identified by the researchers using the European Space Agency’s Gaia space observatory, and their composition was determined using telescopes in Chile and Hawaii. The stars ranged in distance from our solar system from 70 light years to 960 light years. The distance that light travels in a year is 5.9 trillion miles (9.5 trillion kilometers), or one light year.

Although the likelihood of their data indicating the consumption of entire planets is high, the possibility exists that the food source was planetary building blocks devoured during the planet formation phase of the system.

Our sun and similar stars explode violently in their final moments, swallowing any nearby planets and exploding into a dense, blackened cinder known as a white dwarf.

“Like the sun, all stars will someday grow to be huge stars. Earth will someday be swallowed by the sun’s expanding envelope, according to Ting.

But rather than being close to the end of their lives, each person in this study was in the prime of it.

Approximately 8% of the investigated stellar pairs had one star that appeared to have swallowed a planet, suggesting that instability in planetary systems may be more widespread than previously thought.

According to Ting, the majority of planetary systems should to be stable since, similar to our solar system, the planets are mostly influenced by their host star rather than by their sister planets.

“But for other planetary systems with different initial conditions and configurations, this might break down, leading to very chaotic dynamics,” Ting said.

According to Ting, “a non-negligible fraction of planetary systems are indeed unstable, meaning there are always planets being ejected in or out.” This is supported by the study.

There may be more of these planetary exiles than previously thought, given that only a small number of these roaming planets might actually get consumed by their home star rather than just floating around the universe.

“Understanding which planetary systems are stable or not is a long-time goal of planetary dynamics theorists,” Ting added.