As humans, we require an abundance of nutrients to maintain our health. In fact, this is true of every living inhabitant of our planet. When pondering our space in the pale-blue world we share on this spiral arm of the Milky Way, questions arise. Are there planets out in the vast universe like ours on which humans can survive? How do we know where to look and where not to look for such planets?
A recent study, published in Nature Astronomy, found that some stars, like our sun, need nutrients just as urgently as humans. In a cannibalistic pursuit to gain these nutrients, these stars eat and absorb their nutrient-rich planets so that they can survive longer. The results of this study provide us with the perfect answer of where not to look when it comes to finding the next Earth-like place.
Have no fear! Thankfully our sun does not need to gobble us up for nutrients. Yet, how could we possibly know if a star behaves like ours or if it is a cannibalistic monster? The answer lies in the atmospheres of the star.
The awesome fact about binary systems is that these systems possess two suns. In this study led by Dr. Lorenzo Spina, of the INAF-Astronomical Observatory of Padua, Italy, 107 binary systems were investigated. Choosing binary star systems gave the study two similar suns to compare, as these systems were picked for their twin-like suns.
Under our telescope’s examining eye, 33 out of 107 of the binary star systems exhibited increased levels of iron in their atmospheres. Since stars are mostly made up of lighter elements such as hydrogen, helium, carbon, and oxygen; increased levels of iron in a sun’s atmosphere are the tell-tale sign that the sun is a planet eater.
Why do these shamelessly cannibalistic suns need to eat their planets? In the case of older suns, running out of essential nutrients is an issue that is resolved through the absorption and consumption of the planets closest to them.
“Such events could happen in systems where gravitational interactions among the planets would either fling one into the central star or bring it close enough for the star to slowly vaporize and devour it.” The results of this study tell us which star systems to actively avoid in our conquest for Earth-like planets.