Approximately 90 percent of all stars in the universe will turn into a planetary nebula, which could also happen to the sun when it dies in about 5 billion years.
Planetary Nebula
A team of international astronomers predicted that the sun in the Solar System will most likely transform into a luminous interstellar gas and dust called a planetary nebula. Scientists initially did not know the fate of the sun until they have developed a new stellar model that can predict the life cycle of stars.
"When a star dies it ejects a mass of gas and dust — known as its envelope — into space. The envelope can be as much as half the star's mass. This reveals the star's core, which by this point in the star's life is running out of fuel, eventually turning off and before finally dying," said lead author Albert Zijlstra, a professor in the School of Physics and Astronomy at the University of Manchester in the UK.
Once a planetary nebula is formed, its envelope will shine brightly for around 10,000 years, which is equivalent to a brief period in astronomy. Stars with lesser mass than that of the sun emit fainter light compared to massive stars.
The new model suggests that low-mass stars like the sun heat faster than larger ones to form a planetary nebula. Zijlstra said a breakthrough study like this allows researchers to measure the presence of stars even in distant galaxies just by looking at how bright its luminosities are.
Details of the study are published May 7 in the journal Nature Astronomy.
Composition Of Planetary Nebulae
In a study published in the August 2012 issue of The Astronomical Journal, 21 planetary nebulae were already observed using NASA's Chandra X-ray Observatory and the Hubble Space Telescope. The ones observed through Chandra emit a purple color while those from the Hubble produces red, green, and blue colors.
The shell-like filamentary structures of planetary nebulae are caused by the rapid wind emanating outward from the star's core. The study reported that one of the 21 documented planetary nebular showed high-energy X-rays that are likely caused by a companion star.
"The new survey data reveal that the optical images of most planetary nebulas with diffuse X-ray emission display compact shells with sharp rims, surrounded by fainter halos," NASA reported.
Researchers said future studies can explore the role of double stars in the formation and evolution of planetary nebulae.
The Aftermath
Currently, astronomers measure that the sun is midway along its predicted lifespan. As it ages, the hydrogen on its core will run out, leading to its collapse. Nuclear reactions will take place outside its core, which will eventually engulf Mercury and Venus.
The outer mass of the sun will be blown off at a rate of 20 kilometers per second producing ultraviolet light and x-rays. The temperature will reach 30,000 degrees Celsius that life on Earth will cease to exist even if the planet will survive the sun's explosion.
