Scientists have discovered an "impossible" white dwarf that made them scratch their heads, as they cannot explain what happened to its mass, according to a study published on 5 August in Astrophysical Journal Letters. The mass of white dwarfs is based on that of the original star and can be used to determine its age. Previously, scientists detected 100 white dwarfs with very low mass, which suggests that they are older than our universe. They tried to explain this conundrum by saying that almost all of these white dwarfs have companion stars that could filch their neighbours' mass and make them appear older than they actually are.
However, the latest finding by a team led by Kento Masuda has baffled scientists, as the white dwarf in question also has a companion star, but it is located too far to be able to steal its mass. "This finding suggests that there is something missing in our current understanding of low mass white dwarf formation and/or binary interactions", Kento Masuda, lead author of the research and an astronomer at Princeton University, told Space.com.
Scientists discovered the mysterious white dwarf using data from NASA’s Kepler telescope. Because the odds are low to find a white dwarf with extremely low mass using the instruments that the researchers had, scientists assume that this could mean that "impossible" white dwarfs are far more common than previously imagined.
Kento Masuda said that he and his colleagues would continue searching for small white dwarfs with companions in order to learn more about their properties.