The material emitted by the supernova will initially expand very rapidly, but then gradually slow down, forming a complex giant bubble of hot luminous gas. In the end, the “charred” remains of the exploding white dwarf will overtake these gaseous layers and go on a journey through our galaxy.
A new study showed that a strange white dwarf flying along the Milky Way may be the remains of a supernova outbreak. White dwarfs are the cold, dull nuclei of dead stars the size of the Earth, which remained after the medium-sized stars had exhausted their fuel and lost their outer layers. Our sun will one day become a white dwarf, like more than 90% of the stars of the Milky Way.
Previous studies have shown that white dwarfs usually have internal structures. Their nuclei are mainly composed of carbon and oxygen, which is usually surrounded by a layer of helium, and then a layer of hydrogen. In a new study, scientists focused on the white dwarf SDSS J1240 + 6710, located about 1430 light years from Earth. An unusual atmosphere was found at the object, which seemed to contain neither hydrogen nor helium, but instead consisted of a strange mixture of oxygen, neon, magnesium and silicon.
Using the Hubble Space Telescope, scientists studied the dwarfs in more detail and came to the conclusion that it flies 900,000 kilometers per hour in the opposite direction to the rotation of the galaxy. Moreover, it had a particularly low mass. This may mean that it could be thrown away by a supernova explosion, and now these remains are carried along the Milky Way.