Planet-eating stars are surprisingly common in the universe. Astronomers have found out by examining dozens of twin stars that apparently one of every 12 stars in the world has swallowed its planet.
Planet-eating stars are surprisingly common in the universe
Planet-eating stars are surprisingly common in the universe. Is our solar system a normal system or a unique one? This mystery is one of the biggest questions in astronomy, and scientists have come a little closer to the answer by examining more than 5,500 exoplanets that have been discovered around other stars. However, the answer to the puzzle is confounded by a fairly significant problem: some stars eat their planets, making learning what is considered “normal” for planetary systems a little more laborious.
Now, according to a new study published in the journal Nature, planet-swallowing may not be an unexpected event, but a common one in the cosmos. An international team of scientists looked at dozens of closely related pairs of twin stars (stars that were born at the same time from the same protostellar cloud). It was expected that both twin stars would have started their lives with basically the same compositions, But scientists have found that this was not always the case. In 8 percent of those twin pairs, one of the stars visibly ejects masses of elements typically found in planets.
Gravitational perturbations can regularly fling rocky worlds toward their stars, even in mature systems.
Astronomers have previously studied stellar twins to discover greedy planet-eating stars, But the findings were never so conclusive. Yuan Sen Ting, an astrophysicist at the Australian National University and one of the authors of the study refers to the high strength of the observed signals and describes the study’s finding as a low estimate.
The authors of the study suspect that the indigestion observed in the stars reflects a change in their dietary intake during adulthood; That is, when unstable orbital paths regularly send planets into the star’s hellish embrace. This suggests that gravitational perturbations, possibly from passing stray stars or migrating gas giants, can regularly throw rocky worlds toward their stars, even in mature systems.
Planet-eating stars are surprisingly common in the universe
The recent discovery also offers a more efficient way to search for exoplanets. Lorenzo Spina, an astrophysicist at the Padua Astronomical Observatory in Italy, to Scientific American “In the future, we could use the abundance of chemicals in stars to select priority targets when searching for planets,”. Spina believes that stars that lack signs of planet-swallowing are more likely to host a system similar to our own cosmic neighborhood.
In the vast field of research to understand the life and death of planets, finding such strong evidence of their being swallowed by their stars is an explanation for an age-old puzzle. For years, stars exhibiting strange rotations, unusual flares, or special chemical compositions have puzzled astronomers. Stars that are strangely refractory elements (iron and even metals more resistant to evaporation) seem suspicious objects; Because such durable materials often make their way to planets.
But by examining individual stars, it was difficult to tell whether the star had turned its planet into its meal or formed from a unique interstellar cloud. In contrast, stellar twins born at the same time from the same cloud are ideal for unraveling the mystery. “Just like many sociological studies, twins are surprising,” says Ting. Because by going to them, you eliminate all other confounding factors.” If one of those twins has a high compositional similarity to its protostellar cloud, but its stellar sibling contains large amounts of silicon and iron, the latter has most likely returned from a planet-swallowing feast.
The research team used the European Space Agency’s Gaia space telescope to obtain the maximum sample size. This space observatory is particularly good at tracking the journey of billions of rotating stars in the Milky Way. In fact, Gaia is such a useful tool that its data can be used to retrace a star’s long-term motions and reveal its close relationship with other distant stars. In this way, the researchers identified 91 pairs of twin stars, many of which were not so dissimilar to our Sun.
The researchers then recorded the stars’ chemical composition using large ground-based telescopes and identified 21 elements commonly associated with planets, including carbon, oxygen, silicon, iron, nickel, and zinc. “We can detect all the subtle differences in these different elements,” says Fan Liu, an astronomer at Monash University in Australia and one of the study’s authors. Liu and his colleagues observed signs of a planetary engulfment event in 8 percent of the pairs.
Planet-eating stars are surprisingly common in the universe
The Earth may exist simply because the Sun did not want to swallow its planets
Many questions remain unanswered; Like what kinds of planets tend to be eaten by their stars, and how to be sure if any star has completely avoided swallowing its own planets.
But are 8% or more of all stars likely to be planet eaters? Circumstantial evidence inconclusively points to the same, But evaluating such a rate is very challenging. Even a sample of 91 stellar twins is tiny compared to the hundreds of billions of stars in the Milky Way, let alone countless stars in other galaxies.
What do the study’s findings say about our middle-aged Sun? Our star has no known fraternal twin, But numerous studies of similar stars elsewhere in the galaxy suggest that the Sun is not particularly enriched in refractory elements. In fact, it even seems that the sun is depleted of these elements, and this feature makes it appear unusual in another aspect. “The further we look into our own solar system, the weirder it gets,” Kane says.
According to Spina, we have discovered that there is a huge variety of planetary systems in the universe. Considering this extraordinary environment, our own neighborhood seems a bit dull. The solar system is not chaotic and all the planets are well placed around the sun. Earth may exist simply because the Sun, unlike many other similar stars, has not tended to swallow its planets.