A study published on Tuesday in the journal Nature Communications suggests that there are 15 “chemically peculiar” stars in the Milky Way.
These 15 chemically peculiar stars can’t be explained by existing theories. They contain a lot of phosphorus, a chemical which does not occur naturally in big quantities.
The scientists who published the paper are affiliated with the department of astrophysics at Universidad de La Laguna and the centre for information and communications technology research at Universid de da Coruña, in Spain.
In their paper, they said that origins of phosphorus is of “extreme interest” because it’s widely accepted to be essential for life on earth, but many of the stars which we have previously discovered don’t have it in abundance.
Speaking to Vice, Thomas Masseron, the lead author, explained that the group has a couple of theories about what might have happened – these phosphorus rich stars may have been born out of the ashes of a previous generation of massive stars, which overproduced phosphorus in our lifetimes.
"These results show that not only are we dealing with a new type of objects but that their discovery opens the way for the exploration of new physical mechanisms and nuclear reactions which occur in stellar interiors," he said.
Another theory is that these stars may have absorbed phosphorus from another star orbiting close to them, or they may have merged with other stars. However, many of the actual observations by the scientists didn’t directly suggest that any of these theories are true.
However, other elements which are present in these stars include magnesium, silicon, oxygen and even elements like cerium, which are heavier and not so easy to find.
To the authors of the paper, this suggested that they may have to develop new methods of understanding reactions that occur between and within stars, and that there may still be a long way to go before they fully understand how these stars came to be.
The team is planning to study these stars at different wavelengths to see if there are other commonalities or aberrations that they can’t understand yet – and to keep looking even further outfield to try and find more phosphorus rich stars.
“The paper is all about exploring all possibilities and ruling out all of them,” said Masseron. “Basically, the answer is we don’t know.”