Our Sun was born about 4.56 billion years ago from scattered fragments left as protracted relics of early generations of stars who died long ago - their nuclear floating fires extinguished after they consumed the necessary fuel. Stars of all sizes explode ever heavier and heavier atomic elements from lighter ones, and when they reach the end of this long star road, they send their freshly merged batch of heavy atomic elements into the space between the stars, where they can be included in the newly lit lights of younger ones. star babies. The explosion of the Big Bang of the Universe, which occurred about 14 billion years ago, produced only the lightest of the atomic elements — hydrogen, helium, and traces of lithium. All atomic elements heavier than helium, called metals astronomers were made in the furnaces of hot furnaces of stars.
red giant is a bright brilliant crimson star with low to medium mass, and these old stars are in a late stage of stellar evolution, their external gaseous atmospheres are bloated and weak. These dying stars have a large radius, and the surface temperature is "only" around 8540 degrees Fahrenheit - or even lower - which is very cool for a star. In a research paper published in the journal October 30, 2017 Astronomy of nature , a group of astronomers led by Dr. Vurer Vlemming from Chalmers University in Sweden published for the first time information about the surface of an elderly person. red giant star with the same mass as our own middle-aged sun - giving a preview of our star.
Observations revealing aging, distant red giant were identified by Chalmers astronomers from images they received from Atacama Large millimeter / submillimeter array (ALMA) located in the Atacama Desert in northern Chile. The elderly star was gigantic, with a diameter twice the orbit of the Earth around our Sun. In addition, the star's atmosphere impacted by unexpected strong shock waves.
red giant star named W hydrae , is 320 light years from our solar system, which practically places it in the cosmological backyard of the Earth, and is in the constellation Hydra, Water snake.
W hydrae is an example of what is called asymptotic giant branch (AGB) star. AGB the stars are bright, cool, mature and in the process of losing mass with their strong and merciless stellar winds. This name is taken from AGB stars on Hertzsprung-Russell stellar evolution scheme which classifies stars according to their brightness and temperature.
Dr. Vlemings explained in November 2017 Chalmers University Press Release that "it is important for us to study not only what red soldiers how they change and how they populate the galaxy with elements that are components of life. ALMA in their configuration with the highest resolution, we can now make the most detailed observations of these cool and exciting stars. "
Stars resembling our Sun have evolved over many billions of years. Our average age of the Sun still remains about 5 billion years before it reaches its death. However, when a star resembling our Sun reaches old age, these star older people inflate and grow, become cooler and more vulnerable to the loss of their material as a result of powerful, fast-moving winds. Sun-like stars produce important elements - such as carbon, nitrogen and oxygen - in their hot, hot nuclear fusion ovens. When do these stars reach red giant stages of their development, these heavy metals released into the interseasonal space available for use by later generations of new children's stars.
ALMA & # 39; s images provide the best possible surface appearance red giant star that sporting mass, similar to our own sun. Early detection of images showed details of much more massive red supergiant stars such as Betelgeuse and Antares.
Red giant stars show colors that range from yellow-orange to red, and the most abundant red giants are stars on red giant branch (RGB) of Hertzsprung-Russell diagram. These red giants still capable of draining hydrogen into helium in a shell that surrounds the inert helium core. These crimson giants have a radius of tens and hundreds of times larger than that of our Sun, but their outer gas envelope has a much colder temperature, providing them with a reddish-orange color. Although red giants have a lower energy density in their shells than our Sun, they are many times brighter because of their gigantic size. Indeed, Rgb the branches of the stars occupy an impressive luminosity, which can be almost three thousand times greater than that of our Star.
Red giants evolved from main sequence stars - as our own Sun, - that sports masses from 0.3 solar masses to 8 solar masses. When a star is born from a crumbling cold, dark, gigantic molecular cloud hiding with great love, in the space between the stars, it mainly consists only of hydrogen and helium - with relatively scant quantities metals. These elements are usually mixed and scattered throughout the star. Newborn star reaches main sequence its stellar "life" when its core rapidly rises to a temperature high enough to begin to drain hydrogen (several million kelvins). When this temperature is reached, the young star establishes a hydrostatic equilibrium, where gravitational gravity tends to pull all of its stellar material inward, while at the same time it tests the radiation pressure to push everything out. This necessary and delicate balance between two forces everlasting forces makes the star to stay fresh and fluffy for the duration main sequence. For all my "life" on main sequence , the star gradually merges the hydrogen in its core into helium. However, an aging star is indeed forced to face its inevitable death, after she managed to fuse almost all of its supplies of hydrogen fuel into its boiling core. Relatively small stars, such as our Sun, remain on the burning of hydrogen. main sequence about 10 billion years before they die. Alas, the more massive stars "live" quickly and pay for it to the "dying" young. These massive stars burn hydrogen stocks a lot of faster than their lesser celestial relatives, and, therefore, have shorter “lifetimes”. Red Dwarf Stars the smallest true stars in the universe can live trillions years. Since our universe is "only" about 14 billion years old, there is no red dwarf the relict inhabiting our Cosmos - at least not yet.
When main sequence the star has finally managed to burn the hydrogen fuel in its core, nuclear reactions can no longer continue. At this stage, the nucleus begins to shrink due to the attraction of its own gravity. This reduces the additional hydrogen to the zone where the temperature and pressure are high enough for nuclear fusion to resume in the shell surrounding the core. The outer gaseous layers of the star begin to expand sharply - and this causes red giant the stage of existence of the former Sun-like star. As the star continues to expand, the energy that is produced as a result of the burning of the shell spreads to a much larger surface area. This leads to a lower surface temperature, as well as a shift in the visible light of the star to red - therefore, becoming red giant.
The life cycle of our star
Our sun was born a member of the dense open cluster along with thousands of other sparkling sister stars. Many astronomers believe that our young Sun was ejected from its ancestral cluster as a result of gravitational interactions with the stars-brothers, or that he just ran away from home about 4.5 billion years ago. Our long-lost brothers and sisters also wandered to more distant areas of our Milky Way Galaxy, and it could well be as many as 3,500 of these star bums that exist in the space between the stars.
Like its native stars, our Sun was born in a cold, cold and incredibly dense blob tucked into twisted, wavy folds of one of the many gigantic, dark and frigid molecular clouds that can be found scattered throughout our galaxy. Dense blob ever collapsed under the weight of its own gravity, creating a new star. In the hidden folds of these huge and beautiful clouds , consisting of dust and gas, the fragile tendrils of a material usually merge, and then come together and grow for hundreds of thousands of years. Then, tightly compressing the crushing force of gravity, the hydrogen atoms inside this cluster suddenly merge. This illuminates the star lights that will burn as long as the new star lives, because that is how a star is born. While this may seem counter-intuitive, everything must be very cold for a burning and fiery newborn star to be born.
All our billions of stars in the Milky Way were born this way - as a result of the collapse of a frigid pocket in a cold molecular cloud, consisting mainly of gaseous hydrogen, but also containing less dust. These huge dark clouds of stellar age tend to come together, but stars of similar chemistry usually creep in to the same clouds at about the same time.
As the stars go on, our relatively small Sun does not stand out in the crowd. In the family of our Star there are eight famous large planets, moons and many small objects that are located in a distant suburb of the ordinary, but without a sudden, majestic and very ancient, locked spiral Galaxy, in one of its pens with a pen. If it were possible to trace the history of the atoms found on our planet today, only about 7 billion years old, we probably find them scattered over a wide range through our Milky Way. Some of these scattered atoms are now located in the same chain of your genetic matrix (DNA), although they have long been formed deep inside the ancient, alien stars that live in our young galaxy.
Stars do not last forever. When our Sun and similar stars finally burned their necessary supply of hydrogen fuel, their appearance changed. At the moment, the star is elderly. In the hot heart of an elderly star, similar to the Sun, lies the core of helium. The helium core of our Sun will be encoded inside the shell, in which hydrogen is still converted to helium. The shell will eventually expand outward, as the hot core of the Star grows as it matures. The helium core itself will shrink under its own relentless weight, and it will get hotter and hotter until it is roasted enough in the center to begin another stage of nuclear burning. At this new stage, helium will be fused to produce a heavier atomic element, carbon. In about 5 billion years, our Star will have only a very hot and small core, which will emit more energy than our still “living” Sun at the present time. The outer gas layers of our Sun swell to monstrous proportions, and this will be little reminiscent of the Sun that we see today. Our Star will experience a sea change in bloated red giant. Our swollen, hotter Sun at this stage will first swallow Mercury, and then proceed to absorb Venus. Our Earth may be next, as our Sun continues to consume its inner planets. The temperature on the surface of this bloated sphere of crimson gas will be much cooler than the surface of our Sun. This explains its new - and relatively cool - red tint. However, our Star will still be hot enough to turn the ice inhabitants Kuiper belt, such as Pluto and its big moon, Charon, to tropical areas - at least for a while. Our Sun is doomed, and the core of our dying Star will continue to shrink. Since he can no longer produce radiation through the process thermonuclear reaction , all further evolution will be determined only by gravity. In the end, our Sun will eject its outer gaseous layers into interplanar space - while its core remains intact. All the material of our Star is completely destroyed in this small relic core, which roughly corresponds to the size of our Earth. Now our Sun will become a type of star ghost, called white Dwarf. In our afterlife stars left white gnome the ghost will be surrounded by a beautiful expanding gas envelope called planetary nebula. These beautiful "Cosmos butterflies" got this design, because early astronomers believed that they resemble the planets of the ice giant Uranus and Neptune. white gnome is a dense object that radiates energy resulting from its collapse, and usually consists of carbon and oxygen nuclei floating in the dry sea of degenerate electrons. If any additional mass somehow contributed to this tiny body, it will only lead to less white Dwarf. This is due to the fact that the additional mass white gnome to aggravate even more when its central density becomes greater. The radius of our now dead Sun will decrease to several thousand kilometers. white gnome doomed to gradual cooling over time.
The inevitable end will come when our Sun becomes an object called black dwarf. Black dwarf stars are hypothetical objects. This is because it is commonly believed that so far no one lives in our Universe. This is because for hundreds of billions of years white gnome cool down to black dwarf phase - and our universe is less than 14 billion years old. Cooling white gnome The sun first emits yellow light, and then red light, based on what remains of its reservoir of thermal energy. Its atomic nuclei will be crushed together as much as physically possible. At this stage no further collapse will occur. Our Sun - and stars like this - will cool, becoming probably the same temperature as the extremely cold interstellar medium. black dwarf does not emit light at all. In this final, destructive phase of the evolution of stars, as carbon-rich black dwarf , our Sun will roam the Milky Way. During this long journey, he will be able to meet another molecular cloud - just like the one from which he, and his glittering kindred stars, was born so long ago. If this happens, the Sun will again become part of the process that will spawn a new newborn star with all its charming and beautiful promises of miracles.
Early preview
New observations W hydrae astronomers of Chalmers University were surprised. This is due to the appearance of an unexpectedly compact and bright spot. This bright spot indicates that the star has hot gas in the layer above the star's surface: a chromosphere.
Measurements W hydrae a bright spot indicates that in the atmosphere of a star there are extremely strong shock waves that reach higher temperatures than those predicted by theoretical current models for AGB stars, explained Dr. Theo Howry to the press. Dr. Khoury is an astronomer at Chalmers University and a member of the team.
However, there is an alternative possibility that is at least as amazing. This possibility indicates that the star observed a giant flash when conducting observations.
Currently, astronomers are conducting additional observations, and ALMA and other tools in their quest to understand W hydrae amazing atmosphere. Although observations from ALMA & # 39; s the configuration with the highest resolution is a difficult task, they are also awarded. As the team member Dr. Elvir De Beck, also an astronomer at Chalmers, told the press service:
"Humility look at our image W hydrae and see its size compared to the orbit of the earth. both of us about our origin and our future. "
