Stars all around the universe appear in different colors. The hottest of the hot are white, followed by blue, and somewhere near the bottom of the color spectrum are red and brown, which are some of the coldest stars out there.
But for the first time, researchers now suggest that a star’s color can also be impacted by the planets they devour. The research appears in a paper shared on arXiv.org.
As stars grow, or planets hurdle to their demise through gravitational pull, stars have been known to ‘eat’ planets. The planet’s materials typically can’t withstand the immense heat generated by a star’s nuclear fusion, and rather than surviving, they will melt.
But what happens when iron-rich planets are melted down to the core after being devoured by a star?
Researchers Emanuel Tognelli and Pier Giorgio Prada Moroni of the University of Pisa, Italy have suggested that stars devouring planets made up of certain elements may actually change color, even if temporarily.
As explained in the study, which involved the use of computer models the predict what would happen when stars devoured planets as large as Earth, or up to 50 times larger, it was found that stars feeding on iron-rich planets would turn redder, as the iron composition would actually change the chemical composition of the star quite drastically.
The study explains that the metals absorb light in the blue wavelength, and this makes it so the remaining visible light wavelengths are mostly the opposite: red.
Of course, the size and age of the star also has a lot to do with the effect, mostly because larger stars would only really have a dramatic impact if the planet colliding with it were larger as well, and because younger stars have so much hydrogen that a little more iron isn’t going to really do as much as, say, in a star that already has a ton of iron and is on its last legs.
Unfortunately, a computer model is all the team had to go by. There really isn’t any way for scientists to look out into space and push a planet into a star to find out more. These kinds of things happen to much by chance, and so observing it in real life is a problem.
Source: New Scientist
