Something unusual has been discovered, and it’s unlike anything astronomers have seen before
Here’s what we know so far. The object is spotted using the Murchison Widefield Array telescope in Western Australia, and it releases a massive burst of energy three times an hour. It is located relatively close to Earth, roughly 4,200 light-years away.
The team that discovered it think it could be a neutron star or a white dwarf with an ultra-powerful magnetic field. The chances are the object is a magnetar (magnetar is a type of neutron star) whose existence has been only hypothesised until now.
Many neutron stars have strong magnetic fields and, as they spin, produce radio emissions. When these radio beams pass through the Earth, we see them appearing switch on and off very quickly, like in a lighthouse. These neutron stars are known as pulsars. But the new object discovered is bursting energy much more slowly than a pulsar. The researchers believe it to be a hypothetical object known as a magnetar – having strong magnetic fields that interact with the surrounding in a way that causes it to slow down significantly. In other words, it would turn it into a kind of slow rotating pulsar.
Another opinion is that the object is some kind of a strange white dwarf, but it is not clear how a white dwarf could become so radio bright, or it could be something that we have not thought of yet.
A very interesting video is below:
Repeating Transient Animation from ICRAR on Vimeo.
Life Cycle of a Star
However, how the star dies depends on what type of star it is. Massive stars transform into supernovae, neutron stars and black holes while average stars like the Sun end their lives as white dwarfs surrounded by a disappearing planetary nebula.
Main Sequence – The hydrogen protons are converted into helium atoms in this process.
Stars similar like the Sun
When the core runs out of hydrogen fuel, it will shrink due to gravity. As the core contracts, it heats up. It raises the temperature of the upper layers, causing them to expand. As the outer layers grow, the star’s radius will increase, becoming a red giant. The radius of the red giant will be just beyond Earth’s orbit. At some point after that, the core will become hot enough for the helium to fuse into carbon. When the helium fuel runs out, the core expands and cools. The upper layers will expand and eject material, forming a planetary nebula around the dying star. Eventually, the core will cool down into a white dwarf and finally into a black dwarf. This whole process will take a few billion years.
Stars larger than the Sun
When their cores run out of hydrogen, these stars, like the Sun, fuse helium into carbon. However, after the helium is gone, its mass is enough to fuse carbon into heavier elements like iron. Once the core has turned to iron, it can no longer burn. The star collapses by its own gravity, and the iron core heats up. The core becomes so tightly packed that protons and electrons merge to form neutrons. In less than a second, the iron core, which is roughly the size of Earth, shrinks to a neutron core with a radius of about 10 kilometres. The star’s outer layers fall inside the neutron core, crushing it further. The core heats up to billions of degrees and explodes (supernova), releasing large amounts of energy and material into Space. Shock waves from supernovas can trigger the birth of other stars. The rest of the core can form a neutron star or a black hole depending on the mass of the original star.
Source: Image and ScienceAlert