Stars do not live forever, and when they perish they can disappear into eternity with either a bang or a whimper, depending on their mass. Furthermore, stars can do some very strange things when they come to the end of that long stellar road–and a distant dying star dubbed V Hydrae has been observed to be behaving very strangely, indeed. In October 2016, astronomers announced that NASA’s Hubble Space Telescope (HST) has spotted some searing-hot blobs of glaring gas, each twice as massive as the planet Mars, being shot out near V Hydrae. The big blobs of super-hot plasma zoom out so fast into the surrounding space that it would take only half-an-hour for them to zip from Earth’s Moon to our planet. This puzzling stellar “cannon fire” has been occurring once every 8.5 years for at least 400 years–and now astronomers have proposed a new explanation for this strange behavior among the stars.
The fiery blobs of super-hot gas present a mystery for astronomers to solve. This is because the rudely evicted material, that is being shot into space like a series of celestial “cannonballs”, cannot have come from V Hydrae. This dying star is a swollen red giant, dwelling 1,200 light-years away from Earth, which has probably ejected at least 50% of its mass into the space between stars during its final death throes. Red giants are the doomed and dying remains of small Sun-like stars that have grown old, after having exhausted their necessary amount of nuclear-fusing-fuel–and have now bloated up to monstrous proportions as they approach the sad end of their shining stellar existence.
Of Red Giant Stars And Celestial “Butterflies”
Red giant stars are enormous, luminous old stars that have evolved from small or intermediate mass stars of approximately 0.3 to 8 times solar-mass. These gigantic, elderly stars are in the late stages of stellar evolution, and are about to meet their inevitable destiny. Yellow-orange to red in color, the outer atmosphere of a red giant is both tenuous and bloated–which is the reason why these old stars possess such huge radii, as well as low surface temperatures of only 5,000 Kelvin–or lower.
Even though red giants are about to go gentle into that good night, they still have some life left in them because they are still capable of fusing hydrogen into helium in a shell surrounding a degenerate core of helium. The closest red giant star to Earth is Gamma Crucis, which is a mere 88 light-years away. However, there is an intriguing orange giant star, dubbed Arcturus, that some astronomers think is a red giant–and it is only 36 light-years away.
Red giants display impressive radii tens to hundreds of times greater than that of our Sun. However, their outer gaseous envelope is much cooler, which is the reason why they show a cool reddish-orange hue. Even though these gigantic old stars are many times more luminous than our Sun, their gaseous envelopes have lower energy density because of their huge size. In fact, these dying stars display luminosities that are approximately one hundred to several hundred times that of our Sun! 바카라사이트
Red giants are the remains of small Sun-like stars that were on the hydrogen burning main sequence of the Hertzsprung-Russell Diagram Of Stellar Evolution before they used up their necessary supply of fuel. An infant star, or protostar, is born as the result of the collapse of an especially dense pocket located within the undulating, swirling folds of one of the numerous, billowing, cold, and dark giant molecular clouds that float like lovely phantoms throughout our Milky Way Galaxy. Giant frigid molecular clouds are primarily made up of hydrogen and helium, sprinkled with only a pinch of heavier atomic elements. Hydrogen (the most abundant atomic element in the Universe), and helium are the two lightest of all atomic elements, and both were born in the inflationary Big Bang birth of the Universe almost 14 billion years ago–along with very small amounts of lithium and beryllium. All atomic elements heavier than helium are termed metals in the terminology that astronomers use, and all of the metals were formed in the nuclear-fusing furnaces of our Universe’s myriad of stars–or else in the violent, furiously hot and brilliant supernovae explosions that dramatically herald the raging death throes of massive stars. The heaviest atomic elements of all are born in the fantastic fireworks of glaring supernovae blasts.
The metals are all uniformly dispersed throughout the entire neonatal star. The baby star at last reaches the hydrogen-burning main-sequence when its core grows sufficiently hot enough to commence the process of nuclear-fusion–whereby lighter atomic elements are fused into ever heavier atomic elements. The process of nuclear-fusion begins at the toasty temperature of a few million Kelvin, and at these temperatures the baby star can at last begin to fuse hydrogen in its heart and establish hydrostatic equilibrium. Throughout the entire main-sequence “life” of the star, it gradually continues to fuse the hydrogen in its searing-hot core into helium. The “life” of a star comes to an end when almost all of the hydrogen in its heart has been fused.
Our own Star today was also born within a dense pocket embedded within the billowing, swirling folds of a dark and frigid giant molecular cloud composed of mostly hydrogen gas and a pinch of dust. Today our Sun is a small middle-aged main-sequence Star sometimes called a “yellow dwarf”. There is nothing particularly special about our Sun–it is like billions of others of its kind scattered throughout Space and Time. There are planets, moons, and an assortment of smaller objects circling our Star, which is comfortably situated in the far suburbs of our large, majestic, barred-spiral Milky Way Galaxy, in one of its pin-wheel-like arms.