Astronomers have discovered two new objects that complement the strange objects discovered in 2018 and combine to form a new type of cosmic explosion,media slash Gear reported. This type of explosion has some common characteristics with supernova explosions of large-mass stars and explosions that produce gamma-ray bursts. Despite the similarities, this new explosion category is markedly different from other categories of explosions.
In June 2018, astronomers observed for the first time a cosmic explosion with amazing features and behavior. The object is known as AT2018cow, or nicknamed the Cow. Because the object has some common properties with supernova explosions, but different in some key features, the “cow” has attracted the attention of scientists around the world and has been widely studied. The two new explosions are CSS161010 and ZTF18abvkwla or “The Koala”. The first was discovered in 2016, about 500 million light-years from Earth.
The other was discovered in 2018, 3.4 billion light-years from Earth. Both objects were discovered using telescopes similar to visible light to scan large areas of the night sky for automatic celestial surveys. The scientists who studied koalas noted that the object’s radio wave emissions were comparable to that of gamma-ray bursts. Researchers investigating CSS 161010 say it sprayed “unexpected” material into interstellar space at more than half the speed of light.
In both cases, subsequent observations showed that the two objects share common characteristics with the “cow”. The scientists concluded that these events, known as “fast blue optical transients” (FBOTs), represent a significantly different kind of stellar explosion. Fast blue light transients start in the same way as some supernovae and gamma-ray bursts, and the difference sits after the initial explosion.
Scientists determined that the “fast blue optical transient” had the so-called “engine” seen in other types of explosions, but it was wrapped in thick material, most likely when the star fell off before it exploded. After an explosion, when the thick material near the star is hit by the explosion wave after the explosion, a bright visible burst of light appears, which is what makes these objects unusual. Scientists say the shroud of dense matter means that protostars are different from the ones that cause gamma-ray bursts. Scientists believe that explosions like this occur in small dwarf galaxies, whose properties allow for some very rare stellar evolutionary paths and lead to unique explosions.