Scientists have identified a planet candidate that may have formed from the materials left behind by a dead star. If the discovery is confirmed, it could be the first recorded example of a "second generation planet" observed around a white dwarf star.
According to the research published on October 5 in the journal Nature Astronomy, the planet candidate is located around the white dwarf named HS 0209+0832, which is approximately 270 light-years away from Earth.
By examining data obtained from NASA's Hubble Space Telescope and other observatories, researchers found chemical traces that indicate that the planet may have formed from materials scattered into space during the star's death process.
When Sun-like stars reach the end of their lives, they first expand greatly and turn into red giants. It then blows its outer layers into space, leaving behind a hot, dense core, the white dwarf.
Some planets can survive this catastrophic transformation of the star. However, these are defined as "first generation" planets that formed together with the star.
The candidate around HS 0209+0832 is different. According to researchers, the celestial body in question may have been formed by the recombination of gas and dust scattered into space after the star died.
NIOBIUM TRACE DRAWED ATTENTION
The most important finding that attracted the attention of scientists was the unusually heavy elements in the atmosphere of the white dwarf.
In the research, it was determined that elements such as niobium, copper and zinc were found in high amounts. On the other hand, elements such as iron and silicon, which are common on Earth-like rocky planets, were found to be at very low levels.
The researchers noted that the particularly high proportion of niobium is a characteristic trace of the nuclear processes that took place in the final stages of the star's life.
Jamie Williams, the lead author of the study, stated that this chemical composition indicates that the planet candidate may have formed from substances shed by the star during its death.
Data obtained from NASA's TESS satellite also revealed that there are small changes in the white dwarf's brightness that repeat approximately every 4.4 days.
Researchers think this signal is consistent with a giant planet orbiting near the white dwarf, whose atmosphere has been eroded by the star's intense radiation.
The period measured in the study was calculated as 4,399 days. Scientists estimate that the signal may be caused by the temperature difference between the day and night sides of the planet or the tail created by its evaporating atmosphere.
THERE MAY BE A NEW CLASS OF PLANETS
If the discovery is confirmed, the current understanding of planetary systems around white dwarfs could significantly change, according to the researchers.
To date, planets that survived the death of the star have been found around white dwarfs. However, the demonstration that a completely new planet can form from the materials left behind after the death of a star may indicate the existence of a different class of planets.
Scientists define such celestial bodies as "second generation planets".
Researchers underline that although the findings are strong, the existence of the planet has not yet been definitively confirmed.
Williams stated that the object is a "planet candidate" for now and that new observations are needed.
The team plans to re-examine the system with Hubble and NASA's Chandra X-ray Observatory. It is stated that observations with the James Webb Space Telescope can also provide stronger evidence about the existence and characteristics of the planet.
IT MAY ALSO SHED LIGHT ON THE FUTURE OF THE SOLAR SYSTEM
The results of the research are also remarkable in terms of the far future of the Solar System.
When the Sun reaches the end of its life billions of years later, it will turn into a red giant, then lose its outer layers and become a white dwarf.
According to researchers, if it is proven that second generation planets can actually form, it may be theoretically possible for new planets to emerge from the gas and dust left behind after the death of the Sun.
The study is considered an important finding that shows that systems around white dwarfs may enter a new planet formation process rather than ending completely with the death of the star.
