The first evidence of the existence of a “second generation” planet around a dead star has been observed

In a possible cosmic first, scientists say they have spotted a planet that may have formed from the remains of its host star after its death. This planet is believed to be a gas giant orbiting a white dwarf known as “HS 0209+0832,” located about 270 light-years from Earth.

After analyzing data from NASA's Hubble Space Telescope and other observing tools, researchers found chemical evidence indicating that the planet may have been formed from material ejected by the star when it exhausted its fuel and turned into a white dwarf. When a sun-like star dies, it first expands rapidly to become a red giant, then sheds its outer layers, leaving behind a small, very dense, hot core called a white dwarf.

Some planets that formed with the star from the beginning can survive this violent phase if their orbits are far enough away. Scientists have already observed a number of these surviving planets around white dwarfs, but they have not previously confirmed the existence of a so-called “second generation planet,” that is, a new planet formed from the debris of a dead star.

One of the most prominent evidences of the possibility of the existence of this planet is the discovery of unusual amounts of heavy elements on the surface of the white dwarf. Researchers believe that these materials come from a nearby planet whose material is falling onto the star. Among these elements is niobium, which lead researcher Jamie Williams, from the British University of Warwick, said was observed for the first time in a white dwarf in this image.

The team believes that its presence indicates that planetary material may have arisen from the ashes of the star itself during its death. Analysis of NASA's TESS satellite data also showed a weak optical signal that occurs every 4.4 days, which, according to researchers, is consistent with the possibility of the presence of a giant planet orbiting the white dwarf.

Planets close to white dwarfs are characterized by the possibility of having stable habitable areas for very long periods, because white dwarfs cool slowly over time. Williams said a second-generation planet could form and then remain within the habitable zone for tens of billions of years, which could provide more stable conditions for life to arise.

However, the researchers stressed that the discovered object is still a "planetary candidate" and has not been definitively confirmed. After the red giant stage, the dying star can produce various elements as a result of nuclear processes within it.

But when it turns into a white dwarf, the heavy elements quickly fall into the star, and only light elements such as hydrogen and helium usually remain on its surface. So scientists believe that the niobium found on the surface of HS 0209+0832 came from exogenous material surrounding the star.

The researchers explain this by saying that the white dwarf is very hot and emits large amounts of high-energy ultraviolet radiation, which may lead to the stripping of the atmosphere of a nearby planet, and then parts of its matter falling onto the surface of the star. The idea of ​​second-generation planets is not entirely new.

The first planets outside the solar system were discovered around pulsars, which are rapidly rotating dead stars that usually result from supernova explosions. Scientists believe that these planets formed after the explosion, because any original planets would have likely been destroyed.

As for white dwarfs, they do not form as a result of supernovae, but they may be surrounded by large amounts of debris, such as the remains of shattered planets and the gas and dust that emerged from the star during its transformation from a red giant to a white dwarf. It is possible that this material will recombine to form new planets.

Scientists propose another possible scenario, which is that a second body, such as a small star or brown dwarf, entered the star during the red giant phase. This process may have helped prevent gas and dust from spreading far, and instead led to the formation of a disk of material orbiting the white dwarf, from which the new planet emerged.

The researchers plan to continue studying the system using the Hubble Telescope and the Chandra If the discovery is confirmed, this distant world may represent an entirely new class of planets, and means that second-generation planets may be more common around white dwarfs than previously thought.

This discovery has special significance for the future of our solar system, because the Sun itself will one day turn into a white dwarf. Scientists believe that the death of the Sun may not necessarily mean the end of all planets, but rather new worlds may emerge from the materials it leaves behind.

Researchers indicate that more than 95% of the stars in the universe will eventually turn into white dwarfs. If it is proven that planets can form after this stage, this may change our understanding of the life cycle of planetary systems, and reveal that the story of planets does not always end with the death of their stars, but rather completely new chapters may begin after that.