Astronomers discover the chunk of a former planet circling the remains of its former dead star, now called a white dwarf. A white dwarf is what remains when a large star (the size of the sun, or even bigger) eventually shrinks into a dense spark that may resemble the size of the Earth. The solar system is filled these dense embers such as this particular white dwarf.
The piece of the fragmented planet has been studied meticulously to consist of iron and nickel among other types of metals. It also is located 410 light-years away from Earth in the Virgo constellation and estimated to be about 320,000 miles from the white dwarf. The sliver of this former planet is estimated to be a mile or even hundreds of miles in diameter length, but undoubtedly dense enough to withstand the environment and be able to remain following the explosion of what caused this deterioration in the first place. What is assumed to have been a large planet now circles the white dwarf closely enough where each orbit is completed under 2 hours, or every 123 minutes.
Dr. Christopher Manser, physicist at the University of Warwick in England, explains that a body orbiting every two hours is “clear evidence that a planetary body can survive this destructive process. His international team reported its results in Science on April 4th, explaining that “the planet must be unusually small and dense to avoid being ripped apart by tidal forces.”
While the star is in the process of deteriorating into ash, they first increase in size into what is called “red giants,” putting an end to their inner planets. When the sun goes through this process in the far future—in approximately 5 or 6 billion years—it will destroy everything inside the orbit of Mars and it is expected that it will affect the orbits of the other surrounding planets as well. It is unsure at this point in time if Earth will survive this process or be reeled in to the doings of the sun.
Dr. Manser and his colleague Boris Gänsicke from the University of Warwick, have been observing the disc surrounding a white dwarf known as SDSS J122859.93+10432.9 with a range of different telescopes. The most recent telescope that was used was the Grand Telescopio Canarias in La Palma in the Canary Islands in Spain. This white dwarf is known to be one of the few that are known to be surrounded by discs of debris.
Within the orbits, a solid object was also observed spraying a trail of gas. The object appeared as a solid fragment of metal which may be inferred to have been a part of the foundation of the planet. Dr. Gänsicke concludes that if this presumption is correct, “the original body was at least hundreds of kilometers in diameter.” What makes this discovery most unique is that it is only the second reported dense object from a planet to have been found currently orbiting a white dwarf, and as well as the first time that an object have been observed through means of spectroscopy, or observed by emitted light from the tail of gas.
Dr. Manser highlights the revelation behind this study since debris disks are usually known to originate from remnants of smaller bodies such as asteroids or comets that may have been destroyed from tidal forces after being near a white dwarf. The conclusion that was drawn from this discovery was that the new fragment would have to have been a solid metal to have survived the tidal force, according to Dr. Manser. The question of life being present on the fragment would probably be rejected as it orbits too closely to the white dwarf. Dr. Manser states that “it is unlikely that the system is habitable,” as the star appears too dim to provide for the system with planets resting further out.
This discovery, although it brings about many unanswered questions, also encourages additional awareness of what exactly this type of planet used to serve its purpose for while it was fully existent. What were its powerful strengths and its withering weaknesses? Was it able to withstand volatile environments that other planets could not survive? What material is it exactly consisting of that makes it unique compared to other planets that have not been found orbiting their former stars?
Dr. Manser concludes that “we are confident that we will discover additional planetesimals orbiting white dwarfs, which will allow us to learn more about their general properties.”
