Do not enter gently into that good night,
Old age must burn and rave at the end of the day;
Rage, rage against the dying of the light – Do not go meekly into that good night – Dylan Thomas
The stars do not live forever; they cast their beautiful bright light into the pitiless darkness of Space for a while, and then go out like little candles lost in Eternity. Small, lonely stars, like our own Sun, die in relative peace and great beauty, puffing out their outer layers into the darkness of Space. When our lonely sun dies, it will first swell to a bloat red giant star, cannibalizing the inner planets Mercury, Venus and possibly our Earth. Then it will eventually wither into a very dense little stellar corpse called white dwarfthat you will be surrounded by one of the most beautiful shrouds our Universe has to offer: a so-called planetary nebulaan enchanting “butterfly” of the Cosmos, made of multicolored gases that once made up the outer layers of the now dead, lonely little star.
The most massive stars, however, set the Universe on fire when they die as spectacular supernovae. Supernovae are the brightest and most powerful stellar explosions in the Universe, and they can be observed to the most remote corners of the Universe. Stars shatter for two reasons: they have sucked, like a vampire, too much mass from a victim sister star, Prayed they have burned up their necessary supply of nuclear fuel that has kept them bouncing against the relentless force of gravity, and they collapsed dramatically, and then exploded, spewing stellar matter into the Cosmos.
In February 2013, astronomers announced that it is possible to predict when a massive star will go supernova by watching for warning signs of the smaller outbursts it releases just before it explodes with incandescent fury.
star of death
Our Sun, at present, is a commonplace and relatively insignificant, main sequence (which burns hydrogen) star. It is a beautiful, bright golden yellow. There are eight major planets, a variety of mainly icy moons, and other smaller objects that make up the familiar and lovely family of our Sun. Our Solar System inhabits the far suburbs of an ordinary, yet majestic, barred spiral galaxy, the Milky Way. Our Sun, like all the stars, will die. But, today, she is a jumping star, still in active and productive middle age, lighting up the darkness around her with incandescent fire. However, in another five billion years or so, it will be an old star, with little life left in it. main sequence. Stars as small in mass as our Sun typically live for about 10 billion years. But our Star, and middle-aged stars like it, will continue to flood Space with light, burning hydrogen in their hearts as fuel. nuclear fusionfor another 5 billion years, give or take.
When our Sun and other Sun-like stars have finally used up their supply of hydrogen fuel, their appearance begins to change. Now they are old stars. At the heart of an ancient Sun-like star is a hidden heart of helium, surrounded by a shell in which hydrogen is still fusing to form helium. The shell begins to swell outward and the hidden heart grows larger as the star ages. The helium core itself begins to wither under its own mass, heating up wildly until, finally, it becomes hot enough in the center for a new stage of nuclear fusion to begin. Now it is helium that is burned to make the heavier element, carbon. Five billion years from now, our dying old Sun will have a small, extremely hot heart that will emit more energy than our still active middle-aged Sun emits right now. The outer layers of our Star will, by this time, have swelled to frightful proportions: it has become a dazzling glow. red giant star, hungry for the blood of its own planet-children! Ultimately, our star’s core will continue to shrink, and since it will no longer be able to emit radiation through nuclear fusion, any further evolution will be determined solely by the force of gravity. Our angry and dying Star will shed its outer layers, but its heart will remain intact. All the matter on the Sun will eventually collapse into this pathetic remnant object that is only the size of our little planet. In this way, our Star will evolve into the type of stellar body known as white dwarf. HAS white dwarf The star is doomed to get progressively cooler and cooler over time. Ultimately, our Sun will likely become an object known as Black Dwarf. black dwarf stars are hypothetical objects because it is thought that none (yet) dwell in our Cosmos. It takes hundreds of billions of years for a white dwarf to finally cool down to the black dwarf stage, and our Universe is “only” a little over 13.7 billion years old.
Stars that weigh at least 8 times more than our Sun die with much more anger than their smaller counterparts. Massive stars cannot resist the crushing property of gravity. Although the war between good and evil is often mentioned as the oldest conflict, the war between pressure and gravity is considerably older. The pressure, that pushes everything outside–derives from nuclear fusion, and is what keeps a star bouncing against the crushing force of gravity. Gravity seeks to pull everything in. When a star runs out of hydrogen fuel and reaches the point where its thrust pressure can no longer hold up against the pull of gravity, it has come to the end of the road. Supernovae typically explode when the iron core of a massive star reaches 1.4 times the mass of our Sun. The most massive stars in the Universe collapse and disappear entirely, becoming that gravitational monstrosity, a black hole. Massive stars, which are somewhat less massive, explode in supernova explosions, becoming a dense stellar corpse known as Neutron star. neutron stars are even denser than White dwarfs.
forecasting the storm
In an article published in the February 7, 2013 issue of the magazine Nature, An international team of astronomers suggests that it may be possible to predict when a star is ready to go supernova before it undergoes that final deadly explosion. One of the study authors, Dr. Mark Sullivan of the University of Southampton in England, explained in the February 8, 2013 space.com that “For a star like our Sun, the energy it emits from the fusion of hydrogen into helium deep in the core exerts an outward pressure on the star, usually counterbalanced by an inward pressure from gravity. However, if the star’s luminosity increases above a certain amount–the so-called Eddington luminosity–the outward pressure from the resulting radiation is strong enough to overcome gravity, which can then drive an outflow of material. Gravity waves can act as a conduit to move this large Eddington super luminosity in the core in an ejection of material from the star’s outer envelope.”
The team of astronomers used three telescopes in their effort to find out more about the way older stars rage before they die: NASA Fast mission Palomar Observatoryand the Very Large Array (VLA). The researchers began by studying a star that lives about 500 million light-years away from our planet. The massive star weighed about 50 times the mass of our Sun, eventually shattering as a supernova called SN 2010mc.
The astronomers’ study indicates that 40 days before the last deadly explosion, the dying old star emitted a giant outburst, releasing matter equaling about 1 percent of the mass of our star, or about 3,330 times the mass of our star. of our star planet, at about 4.5 million miles per hour.
This burst radiated “about a million times more than the energy output of the Sun in a whole year,” Dr. Sullivan continued to explain. He added that this precursor, however, “is still about 5,000 times less than the energy output of the subsequent supernova.”
The close timing between the smaller outburst and the final explosive end of the star strongly suggests that they are related. One of the study authors, Dr. Mansi Kasliwal of the Carnegie Institution for Science in Pasadena, California, told reporters in February 2013 that “what is surprising is the short time between the precursor eruption and the eventual supernova explosion; one month is an extremely small fraction of the 10 million year lifespan of a star”.
The lead author of the new study, Dr. Eran Ofek of the Weizmann Institute of Science in Israel, noted on February 8, 2013 space.com that probability models showed there was only a 0.1 percent chance that the outburst was a random event.
By comparing their data to three models proposed to explain how the earlier outburst might have occurred, the astronomers found that gravity waves helped pull mass into the star’s atmosphere. Gravity waves are fluctuations that result from matter rising due to buoyancy and then sinking due to gravity.
“Our discovery of SN 2010mc shows that we can mark the imminent death of a massive star. By predicting the explosion, we can catch it in the act,” Dr. Kasliwal continued.
