A team of astronomers has discovered an ultra-massive white dwarf who has a unique trait in the form of atmosphere that contains a mix of carbon and hydrogen. The star has been classified under the name of WD J055134.612+413531.09 ( or WD J0551+4135), and it can be found at a distance of approximately 150 light-years away from Earth.
The mass is quite close to our sun at 1.14, and it appears that it may have surfaced after two white dwarfs, which formed a binary system merged. One of the main researchers who contributed to the project has stated that the new discovery was quite surprising since the were no previous examples.
It is expected that the atmosphere may contain a layer of hydrogen that is sometimes mixed with helium or is a mix of helium and carbon. However, the presence of hydrogen and carbon, along with a thick layer of helium in the middle is quite strange. The star was spotted in data collected by the GAIA spacecraft, which is operated by the European Space Agency.
Two stars united into a giant white dwarf
The researchers decided to learn more about the interesting object with the help of the William Herschel Telescope, which sports an advanced spectroscope. They deconstructed the light that was released by the star and used the information to determine the chemical structure, which comes with a surprising amount of carbon.
White dwarf stars are the remnants of stars that have consumed their entire fuel but did not reach the supernova stage as the outer layers were removed before they become unstable. While the white dwarf observed by the researchers is twice as big as a regular one, the diameter is limited to approximately 66% of that of the sun.
According to the team, the star formed after a merger process, an event that may explain the exotic traits of the object.