IN FIFTY years, the sun will die, and as a result, the Earth will suffer an endless winter. This is the premise of the movie Sunshine, about a team of astronauts sent to revive the sun by detonating a bomb on its weakening portion.
The sun will surely die, but this will happen not in 50 years but in five billion years, said Dr. Augusto Morales, Jr. of the UST Graduate School, whose specialization is Theoretical Physics. And upon the sun’s death, he added, it will steadily increase its size and become a red giant, contrary to the movie’s premise that the sun will ‘burn out.’
“Its volume will increase and it may consume Mercury and Venus,” he said.
However, as the sun becomes a red giant, its heat will slowly increase, which may destroy Earth’s oceans and atmosphere through extreme evaporation and ultraviolet activity. The sun will begin to degenerate and shrink after it consumes its supply of hydrogen in its core. Once the shrinking begins, the heat output will also decrease slowly.
“When the shrinkage is complete, the sun will be considered a white dwarf, after which point it will slowly flicker out. This whole process will take billions of years,” Morales said.
A National Aeronautics and Space Administration (NASA) study of a photograph from the Anglo-Australian Telescope in June 1996 explains what might happen when the sun ‘dies’ in the guise of the Helix Nebula, an interstellar cloud of dust, hydrogen, and plasma.
NASA scientists observed that the Helix Nebula contains a multitude of tadpole-shaped objects formed due to gaseous instabilities. The remaining stellar core glows in light, causing its previously expelled gas to fluoresce. The core will eventually turn into a hot, residual white dwarf. Within a billion years, white dwarfs will cool and fade until they can no longer be seen even with the help of telescopes, since the nuclear reactions fueling the star have already extinguished.
In the movie, an Icarus II spacecraft is launched to drop a stellar bomb to destroy a matter that consumes the sun from the core, said to cause its premature death. Researches made to review the science behind the sci-fi movie revealed that a dangerous matter known as Q-ball can rip neutrons and protons apart and convert them into supersymmetric particles, and in the movie, it is lodged in the sun’s innards, destroying it from inside.
However, the movie gave no explanation on how the Q-ball got into the sun’s core. In reality, Q-ball remains hypothetical. Also, there is no exact proof that a “dark matter,” a component in the supposed stellar bomb to blow Q-balls up, really exists.
Starry life
Almost every characteristic of a star, like luminosity and life span, is determined by its initial mass. Generally, a more massive star has shorter lifespan because such kind of star has greater pressure on its core, burning hydrogen faster.
Also, other factors can determine a star’s age. These are color, size, heat, rotation, and gravitational pull.
According to Morales, younger stars are generally yellow. Aging turns it red, and then finally, bluish white.
“However, color is not a good indicator of a star’s age since a full spectral analysis should be performed,” he added.
Spectral analysis is a method of charting and analyzing the chemical properties of matter and gases based on the color of visible bands in the light it gives off. Furthermore, young stars begin small, then expand to become giants, then again shrink to become dwarfs, like its color phasing. Also, like all other stars, the sun slowly increases heat output, up to its red giant stage. Beyond that, it will gradually cool off.
A star’s rotation also helps determine a star’s age. The rotation rate of stars can be approximated by tracking the rotation rate of its star spots, a region on a star’s surface marked by a low temperature.
Younger stars usually have a rapid rate of rotation greater than 100 kilometers per second at their equator, compared to aged stars. The sun, comparably, has 1.99 kilometers per second velocity, taking it 25.38 days to complete just one rotation.
The issue of life sustenance of stars has long been in debate, and there has been no proof of life existence other than the Earth’s.
“It depends on a combination of things: distance from the sun, ambient temperature of the sun, and the type of planet,” Morales said.
In the case of Earth, given the present conditions, there are no problems. “But if the sun is a red giant, then, all heavy atoms and molecules that support life would be stripped from the Earth’s surface because of the extreme heat,” he added. According to Morales, as any star dies, it will lose mass. “When it does, according to Newton’s Law of Gravitation, the orbits of the planets may become elongated, since a lighter sun wouldn’t have the mass to maintain its previous gravitational pull,” he said.
Despite the premise of the sci-fi movie Sunshine, current estimates assure that the sun will last up to billions of years. “And beyond that, it’s even difficult to say when the sun will really blink out,” Morales said.
