The ‘zombie’ star, which is scientifically dubbed a white dwarf, is a star that ran out of fuel, but it still displays signs of being alive such as luminosity, which comes from its stored thermal energy, and gravitational pull.
A white dwarf’s gravitational force is tremendous because the star is extremely dense compared with its size. For instance, the white dwarf in question is 2,500 heavier than Saturn but it is seven times smaller.
Furthermore, it is its gravitation the main cause of the glowing ring of debris around it, scientists believe. Researchers at the University of Warwick’s Astrophysics Group explained that the white dwarf’s gravity ripped an asteroid to shreds and formed a Saturn-like ring out of gases and dust particles.
The ring has an eerie dark red glow because the gases released during collisions between debris particles are lit up by ultraviolet radiation emitted by the star.
Scientists have been tracking the said zombie star dubbed SDSS1228+1040 for over 12 years. They where puzzled by the debris ring surrounding the star. Yet, the ring is half the size of our sun and it could contain both planet Saturn and its rings as the gap within it is 700,000 km across.
Researchers, however, found debris rings around other white dwarfs as well but it is the first time we have an image of one such debris disc. Manser explained that scientists worldwide knew about the Saturn-like rings around dead stars for more than 20 years.
In order to obtain the image, researchers combined images taken by the Very Large Telescope in Chile over the course of 12 years. The research team explained that they used Doppler tomography for the photos, just like in CT scans. So, they took a series of images from different angles and combined them into a larger picture.
Manser explained that the data revealed that the debris rings are very similar to those around Saturn. The imagery also revealed that there’s a spiral-like structure within the debris ring, which must be produced by collisions between dust particles.
Scientists believe that the fate of SDSS1228+1040 reflects the future of our solar system, when the sun will run out of fuel.
Prof. Boris Gänsicke recalls that he and his fellow researchers discovered the debris ring in 2006. Back then, researchers thought that it was only an ‘asymmetric shape.’ The new data, however, revealed a detailed view of the system and was ‘definitely worth the wait,’ Prof. Gänsicke added.
Image Source: Wikimedia