A new study reveals the identity of 0,00001% of the double white dwarf that exist in our galaxy. This doubles the number of the ones known until now. We are still far from knowing everything, but step by step, we might make it.
In 2034, a new mission is expected — Laser Interferometer Space Antenna will be launched to detect hundreds of thousands of binary white dwarf stars.
After a process that lasted ten years, Scientists at the Center for Astrophysics Harvard and Smithsonian completed the ELM Survey. Extremely Low Mass spectroscopic study revealed 98 detached double white dwarf binaries.
About the white dwarf binary systems
A white dwarf is the remnant of a star that didn’t get the chance to become a real star. It is a left-over core that missed the mass needed to endure its nuclear fuel burning. There are several kinds of dwarfs in the Universe: red, yellow, orange, blue, white, and brown.
The white kind is composed of electron-degenerate matter. It is thought to be the final stage in the evolution of stars not massive enough to collapse into a neutron star or black hole—stars less massive than roughly nine solar masses. There are also black dwarfs out there. They are white dwarfs that have cooled sufficiently such that it no longer emits any visible light.
The recently spotted ones come with a new trait
The ones found now have a new feature: they only exist because of the other dwarf from the binary system. They have such low mass that seems to outdate the age of the Universe. They couldn’t get to this point by themselves. Only with the help of the companion in a close orbit. That makes the systems to be considered ultra-compact binaries.
“The traditional response to these binaries was to call them supernova progenitors. Someday they will merge together and become something else, and it’s unclear what,” said Dr. Warren Brown, an astronomer at CFA and lead author on the survey.