Stars are like people: they send their dazzling light across the Cosmos for a while, but they don’t last forever in the universal tragicomedy of our existence. Supernovae herald the fatal explosions of massive stars that have reached the end of that long stellar path, having burned up their necessary supply of nuclear fusion fuel, and have perished brilliantly and beautifully, screaming explosively into oblivion. One of the ways astronomers look for clues, hinting at how these massive stars inflate themselves, is by hunting for what is called the parent star of the supernova To carry out their search, astronomers carefully review archival images from the telescope and try to determine the precise location and identity of the supernova. parent star before it was blown to pieces. In November 2018, for the first time, a team of astronomers from the California Institute of Technology (Caltech) in Pasadena announced that they had likely discovered such a star progenitor for a class of supernova known as youtype IC (pronounced “one-C”). Of all the classes of supernovae, this is the only one that did not have a known stellar. progenitor until its discovery. Therefore, its identification was considered by astronomers as a kind of Holy Grail.
Tea Type Ic supernova, nicknamed SN 2017was first seen in May 2017 by astronomers using the Tenagra Observatories in Arizona. It is located in a spiral galaxy called NGC 3938, which is located about 65 million light-years from Earth. Caltech astronomers were able to successfully track this supernova progenitor using archival NASA images Hubble Space Telescope (HST), obtained in 2007.
“An alert was sent when the supernova was initially found. You can’t sleep once that happens and you have to mobilize to try to find the progenitor to the explosion. A few weeks after the supernova was discovered, we found a candidate using both news and archives. hubble photos. The new images were essential to identify the candidate of the parent location,” Dr. Schuyler Van Dyk noted in a Nov. 15, 2018 JPL press release. Dr. Van Dyk is a staff scientist at IPACwhich is a science and data center located at Caltech.
Tea progenitor It turned out to be a very hot and luminous star, and is believed to be either a single massive star 48 to 49 times the mass of the Sun, or a massive binary system in which the star that went supernova weighed 60 to 80 times the mass of our sun.
Gentle IC supernovae
Type Ic supernovaeand their close cousins Type Ib supernovae, are classifications of supernovae that result from the explosive collapse of the core of massive stars. These doomed stars have shed, or more gently shed, their outer envelope of hydrogen gas. When Type Ic and Type Ib supernovae are compared to Type Ia supernovae, do not show the absorption line of silicon. When compared to Gentle pounds, Type Ic supernovae They are believed to have lost more of their original gaseous envelope, including most of their helium. Astronomers generally refer to the two types as “Stripped Core Collapse Supernovae”.
All stars, regardless of their mass, produce mass energy through the process of nuclear fusion of atomic elements, which creates heavier elements from lighter ones. Unlike our relatively small Sun, the most massive stars contain enough mass to fuse elements that have greater atomic masses than hydrogen and helium, albeit at ever-increasing temperatures and pressures. This increase results in a shorter “lifetime” for massive stars. Small stars, like our Sun, “live” in the branch of hydrogen that burns Hertzsprung-Russell diagram of stellar evolution for about 10 billion years. In dramatic contrast, massive stars “live” fast and “die” young. The more massive the star, the shorter its “life” is. A strong star fuses heavier and heavier atomic elements, beginning with hydrogen and helium, and then progressing through the familiar Periodic table until a nucleus of iron and nickel is formed. Because nuclear fusion iron or nickel produces no net output of energy, no further fusion can occur, leaving the nickel-iron core of the damned massive star inert. Due to the lack of power production that creates the necessary external thermal energy pressure to keep the heavy star bouncing against the relentless inner pull of his own gravity, the core shrinks. When the compacted mass of the inert iron-nickel core exceeds what is called Chandrasekhar limit of 1.4 solar masses, radiation pressure cannot counter gravitational compression, and a cataclysmic implosion of the core occurs within seconds. At this point, lacking the support of the now imploded inner core, the outer core of the formerly massive star collapses inward under the merciless force of gravity and reaches a speed of up to 23% of the speed of light. The sudden and dramatic compression increases the temperature of the inner core up to 100 trillions Kelvin. The collapse of the inner core is stopped by neutron degeneracy, resulting in the implosion to ricochet and bounce out. The energy of the expanding shock wave disrupts the overlying stellar material and accelerates it to escape velocity. A hideous, brilliant type II supernovae happens, and where once there was a massive star, there is no star anymore. Depending on the strong progenitor mass of the star, the memory it leaves behind to remind the Universe of its former existence will be a dense, city-sized neutron star gold has stellar mass black hole.
Little stars go to their inevitable Grand finale differently. Type Ia supernovaeunlike core collapse Type II supernovaeThey do not come from the funeral pyre of a huge progenitor star. Type Ia supernovae are the catastrophic remains of small stars, like our Sun, that have perished to become a type of dense stellar relic called white dwarf. Our Sun will never perish in the terrible beauty born of a Type Ia burst. This is because our Sun is a solitary Star. However, when small stars of the mass of our Sun inhabit a binary system with another star still alive, it’s a party set to happen. If the dense, like a vampire white dwarf relentlessly gravitationally sucking in the material of its companion star, it pays for its crime by “going critical.” I mean, the killer. white dwarf it steals enough mass from its companion to reach critical mass to blow itself to pieces, much like its more massive stellar relatives. Alternatively, a Type Ia Supernova It can also occur when a duo of white dwarfs, which make up a binary system, collide with each other. When this happens, it also results in a horrible Type Ia supernova burst.
Putting together how each of these types of supernovae (Type II, Type Ib, Type Ia, and Type Ic) occur provides a much better understanding of how the most massive stars in the Universe evolve.
Discovering an elusive and doomed star Progenitor
“Type Ic supernovae They occur with the most massive stars. But we were surprised by how massive this appears to be, and especially by the possibility of a massive two-star system like the progenitor. Although for the last three decades there have been theories that Type Ic supernovae could be the explosions of very massive single stars, more recent alternative theories point to lower mass stars in binary systems as the origins of these explosions,” explained Dr. Van Dyk on November 15, 2018 Caltech press release.
Type Ib and Type Ic differs from Type II because its stellar parents they lose their outer shells of material surrounding their central cores before going supernova. Type Ib and Here they also differ from each other slightly in chemical composition.
“The origins of such explosions are relevant to the entire astronomical community, not just supernova researchers. The results have implications for ideas ranging from star formation to stellar evolution to feedback in the galaxy,” commented Dr. Ori Fox on November 15, 2018. Caltech press release. Dr. Fox is a Support Scientist at the Space Telescope Science Institute (STScI) in Baltimore, Maryland.
Dr. van Dyk continued to observe in the same Press release that “astronomers have been trying to find this progenitor for about 20 years. Humans wouldn’t be here without supernovae–make the chemical elements we are made of.”
The astronomers also commented that they should be able to confirm with certainty whether they have identified the progenitor toward Type Ic explosion in a few years, using hubble or the next james Webb Space Telescope, planned to launch in 2021. As the supernova darkens as predicted, astronomers will have a clearer view of the region around it. if the luminous progenitor candidate was correctly identified in the archival images, then it will have disappeared and should not be detected in the new images. If scientists still see the candidate progenitorthat means it was misidentified and that some other hidden star was the real culprit behind the cataclysmic explosion.
In Memory of Mark.