Astronomers led by the University of Warwick in Britain have identified the oldest star in the Milky Way, collecting the debris of a small planet orbiting it.
Their findings were published yesterday, Saturday, in the monthly notifications of the Royal Astronomical Society, and concluded that the star belongs to the type of faint white dwarf, located 90 light-years from Earth, and the age of the debris of its planetary system around it is more than 10 billion years.
The fate of most stars, including those similar to our sun, is to become a white dwarf, a star that has burned all its fuel and got rid of its outer layers and undergoes a process of shrinkage and cooling, and during this process, any planets revolving in its orbit will be disrupted, and in some cases destroyed, with Leave its debris to gather on the surface of the white dwarf.
For this study, a team of astronomers led by the University of Warwick modeled two unusual white dwarfs discovered by the European Space Agency’s GAIA space observatory. Both stars are contaminated with planetary debris; One was found to be unusually blue, while the other was the faintest and reddest star so far found in the local galactic region, and the team subjected both to further analysis.
Using spectroscopic and optical data from Gaia, dark energy surveys and European Southern Observatory tools to find out how long the star has cooled, the astronomers found that the red star (WDJ2147-4035) is about 10.7 billion years old, of which 10.2 billion years were spent in cooling, as a dwarf. white.
Spectroscopy involves analyzing light from a star of different wavelengths, which can detect when elements in a star’s atmosphere absorb light of different colors and help determine and quantify the elements present.
By analyzing the spectrum from the star (WDJ2147-4035), the research team found the minerals sodium, lithium, potassium and carbon initially detected on the star, making it the oldest mineral-contaminated white dwarf discovered to date.
The second blue star (WDJ1922 0233) is slightly smaller and was contaminated with planetary debris of similar composition to the Earth’s continental crust.