When a star dies, it can explode in a supernova explosion giant, one of the most spontaneous and violent events in the universe. How will these facts help us better understand the universe?
HOW does the SUPER nova explosion occur?
Large stars have short life cycles and die very early. Like all stars, they produce light by fusion, transforming hydrogen into helium. But in most massive stars the process is rapid, meaning they can burn through their hydrogen stores in just a few million years. Compared to the Sun, this process takes up to 10 billion years.
Illustration of a supernova explosion. Source: Wonderopolis
A star exists on a delicate balance between two opposing forces: gravity, which tends to cause it to collapse inward, and fusion pressure, which keeps the star from collapsing at its center. When the hydrogen in the star’s core is depleted, the star will continue to break down helium into heavier elements, first lithium, then oxygen, then other elements of the periodic table, until until iron is formed. Generating heavy elements not only increases the density of the star, leading to an increase in gravity, but the fusion reaction now produces less energy to keep the star more balanced. The star must eventually counteract its own gravity with Electron degeneracy pressure – the resistance to having more than one electron in the same place at the same time.
When the star’s core reaches a critical density of 1.4 times the mass of the Sun, also called Chandrasekhar limit, even electrons cannot save the day. At this point, the star’s core will collapse within seconds, rapidly pulling in its outer shell of gas at a quarter of the speed of light.
Life cycle of stars. Source: NASA
The nucleus continues to collapse inward until the atoms resist further contraction of the nucleus. At this point, the entire nucleus of the atoms becomes a tightly bound mass, creating a solid solid surface. Normally, this mass of compacted grains would exist as neutron starbut if the core of the star is heavy enough, it will continue to collapse and create a black hole.
Meanwhile, the shell of gas fell through the center at incredible speed, slamming into the solid surface of the core, then bouncing off in a massive shock wave, and finally ending in a supernova explosion on a giant planet. (See illustration below)
Source: Night Sky
LIGHT SEARCH
Starbursts produce very large amounts of light in a very short time. On Earth, researchers hope to capture such brief but intense events by looking for bright spots that appear unusually in the night sky. Initially this was done with the naked eye, and some amateur astronomers still search for supernova explosions through telescope observations, but professional surveyors now use automated systems to take pictures of the sky, finding “stars” that don’t didn’t appear there. the night before.
Several supernova remnants captured by NASA’s Chandra X-ray Space Telescope. Source: Chandra X-rays
However, not all they found were stellar explosions. Some are just faint novas, caused by interactions in a pair of stars that cause one of the stars to flash briefly. In August 2017, researchers observed for the first time a kilonova, a much brighter explosion caused by the collision of two neutron stars. Such stellar explosions are believed to be the source of all natural elements heavier than iron.
To find out what kind of nova the explosion came from, the researchers had to examine how the light from the newly emerged bright object changed. But they have to go fast. After the explosion, the light quickly went out. Thus, as soon as a supernova explosion is discovered, astronomers will notify all telescopes in the world to observe this star. Together they measured luminosity at all possible wavelengths and used spectroscopy to determine which elements were present on the star when it exploded.
A simulated supernova explosion has resulted in the formation of the famous supernova remnant Messier 1 (Crab Nebula) in the constellation Taurus. Source: ESA/Hubble
These elements not only scattered around the Universe, but also formed a type of nebula called: supernova explosion remnants (supernova remnant). These nebulae are rich in hydrogen gas, which will again be the incubator for the next generation of stars. Meanwhile, the heavy elements came together, eventually forming a planetary system, orbiting the infant stars in the nebula. By studying supernova explosions, people not only gain an understanding of the life cycles of massive stars, but also of the origins of planets.
TYPES OF SUPER NEWS
The state of the star before it collapses will determine the type of supernova it will create. There are two main types, depending on the amount of hydrogen found after the explosion: Type I Supernova contains only small amounts of hydrogen and Type II Supernova contain more hydrogen.
Type II supernovae, which come from the largest stars, are very short-lived, so the outer shell of hydrogen gas was virtually intact when the star exploded.
However, slightly smaller stars can lose this shell over time, either by their own stellar winds or by being stripped by a nearby star. In type Ib supernovae, the hydrogen gas layer is completely lost, and in type Ic supernova, even the helium layer is lost.
Simulation of a white dwarf star sucking material from its companion star to form a type Ia supernova. Source: Futurism
Meanwhile, Type Ia supernovae are created from smaller stars but are “locked” in a binary system with a white dwarf. Over time, the white dwarf star gradually stripped itself of material from its neighbor, until it reached the critical mass to cause an explosion. Since the luminosity of the stellar explosion will reflect the mass of the star, Type Ia supernovae always have about the same luminosity. This means that astronomers can determine how far the explosion is from us and use this data to measure distances in the universe.
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