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| NASA |
NEWSLINE PAPER,- New stars are constantly born, while others end their lifetime.
However, how fast are the stars shifting in the night sky, and in our galaxy, the Milky Way, how many stars die every year?
According to James De Buizer, a scientist at the Search for Extraterrestrial Intelligence (SETI) Institute, counting the number of dead stars is a complicated task.
The star dies when the nuclear fusion stops. There are two ways that the star ends its life, and that way depends on its mass.
For low-mass stars, nuclear fusion ends when all the hydrogen in the star's nucleus is converted to helium. Without heat and fusion pressure outward, stars will die by themselves.
During the star collapse, the pressure on the nucleus becomes so strong that the remaining helium begins to fuse into carbon and release energy.
The outer star's atmosphere then expands and turns red, thus creating an object called a red giant.
Eventually, the star will release a blistering atmosphere, leaving a dense object known as a white frog.
According to De Buizer, about 97 percent of the stars in the Milky Way, including the Sun, are destined to be white frogs.
Astronomers can see white dwarfs because they emit a unique sign of light. Astronomers use this information, plus the rate of star formation and the total number of stars, to figure out how many stars die each year.
De Buizer said experts predicted one white dwarf planet formed every two years.
Meanwhile, stars whose mass is eight or more times the mass of the Sun, go through different death processes. These massive stars make up only about 3 percent of the stars in the Milky Way, but the impact is very impressive.
The star combines increasingly heavy elements in its core, which eventually become so massive that it cannot withstand gravity.
The result is a massive explosion called a supernova. Then the nucleus of the star lives as a neutron star or black hole.
The last recorded observation of supernovae in the Milky Way was in 1604, but astronomers estimate that supernovas occur once or twice in a century in the galaxy.
In total, with the formation of white frogs every two years or more, plus several supernovae occurring every 100 years, there are a total of 53 stars dying every century in the Milky Way, or about one star every 1.9 years.
(Newsline Paper Teams)