The Greek god Cronos is known for devouring his offspring in fear of being overthrown by one of his sons. In an almost similar event, scientists found that Sun-like stars eat their own planets.
According to The Swaddle, researchers said that it has been common knowledge before that stars could engulf their rocky planets, which could be rich in heavy elements such as iron, silicon, and titanium.
At the same time, some could also carry lighter material, like carbon, helium, hydrogen, and oxygen. When planets are devoured by their suns, these heavy elements will scatter at the outer layer of the star and leave telltale absorption signatures.
How Often Stars Engulf Planets
In the study titled "Chemical Evidence for Planetary Ingestion in a Quarter of Sun-Like Stars," published in Nature Astronomy, researchers narrowed down the binary systems that have a history of their star engulfing their planets.
Astrophysicist Lorenzo Spina from the Astronomical Observatory of Padua said that researchers have known that sometimes stars absorb their planets. According to Science, such stars that are anomalously rich in heavy metals, like iron, but not in other elements, like carbon and oxygen, can be interpreted as a signature of planetary engulfment.
The challenge now is finding how frequently planets are devoured because of the unstable solar systems. More so, their study discusses the possibility of finding stellar systems that host Earth-like planets.
The team looked at 107 binary systems, solar systems that have two Sun-like stars, and found that 33 of those have companions that showed elevated levels of iron compared to the other, signaling planetary cannibalism. In addition, they detected lithium in these systems, further proving their theory.
Their findings suggest that Sun-like stars have a 20% to 35% likelihood of devouring their planets, which likely happen in systems where gravitational interactions among planets would bring it close enough for the star to slowly vaporize or fling it into the central star.
Our Sun Is One-of-Its-Kind
According to Science Alert, the Sun in the Solar System is a one-of-a-kind star in the Milky Way galaxy. Most of the stars are M-type or red dwarfs, but the Sun is a G-type star belonging to the 7% of the kind of stars in the Milky Way.
Furthermore, the Sun is a loner, born with no siblings, unlike how most stars are formed in the Milky Way. Stars usually have at least one companion locked in a mutual binary system orbit. However, some scientists believe that the Sun could have a long-lost twin somewhere in the galaxy.
Researchers believe that studying the planetary engulfment phenomena in binary systems will give additional evidence that a significant number of Sun-like stars had a volatile history. Moreover, it might also shed light on how life began on Earth since the study presented binary systems that are a bit too messy to host life.
This could help narrow down the search for Earth-like planets outside the solar system, although Sun-like stars are relatively rare in the Milky Way.
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