An international team of astronomers has reported the discovery of a previously unknown supernova remnant. It shows a remarkable circular symmetry in its shape.
During a supernova explosion, its shell explodes in all directions, creating a shock wave moving at tremendous speed. It interacts with the surrounding interstellar matter to form a nebula called a supernova remnant.
Generally, supernova remnants appear as diffuse, expanding structures. But there are exceptions to this rule. Recently, a group of astronomers discovered a new supernova remnant completely by accident, which has been labeled G305.4-2.2. It was identified in images taken by Australia’s ASKAP radio telescope.
G305.4-2 caught the researchers’ attention because of its almost perfectly round shape. Therefore, they gave it the nickname Teleios, which means “perfect” in Greek. Observations show that Teleios is either 7,170 or 25,100 light-years away, corresponding to a diameter of 45.6 or 156.5 light-years, respectively. This gives two possible scenarios. Alternatively, Teleios was formed very recently, and its age is less than a thousand years, or on the contrary, its age is more than 10,000 years.
Astronomers emphasize that the exceptional circular shape of Teleios is highly unusual for supernova remnants, as few similar structures exhibit such morphology. To explain its origin, the study authors consider several scenarios. In their opinion, the most plausible is a Type Ia supernova that originated below the galactic plane. Such objects are the result of a thermonuclear explosion of a white dwarf whose mass has exceeded the Chandrasekhar limit. It usually occurs as a result of the merger of a pair of white dwarfs or the white dwarf absorbing the matter of the companion star.
However, scientists emphasize that they do not have direct evidence to definitively confirm this scenario yet. They plan to make high resolution multi-frequency observations of Teleios in the future. This will help calculate its rate of expansion, which will allow more accurate determination of the properties of the remnant.
Earlier we reported on the last time a supernova erupted in our galaxy.
According to Phys.org
