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Solving the mystery of cosmic stardust
Astrophysicists have long been puzzled about the process in which delicate grains of stellar material coalesce into planets and the complex chemistry of all life-forms. On the one hand, they know that the stardust comes from supernova explosions, but on the other hand, the violence of the explosions should rip the dust particles to smithereens.
The conundrum was solved with the help of a fortunately timed supernova called SN2010jl. Before its fiery death in 2010, the star was 40 times the size of the Sun. While observing the supernova through the use of a special spectrograph attached to the Very Large Telescope at Chile’s Paranal Observatory, scientists saw the newly-formed dust grains absorb light immediately after the blast. The measurements of which wavelengths were absorbed by the stardust allowed the researchers to develop a timeline of how the dust is created by the supernova as well as glean information about the physical size of the grains and what material they are composed of. The astrophysicists made ten observations of the aftermath over a period of two and a half years.
A study presenting the researchers’ findings was published recently in the journal Nature. It showed that the formation of the dust started soon after the eruption of the supernova and continued for a long period after the first blast. However, shortly before the main explosion, the star propelled into space gases rich in carbon, helium, and hydrogen. These gases formed a dense shell around the dying star.
When the star exploded, the shockwave slammed into the shell. This compressed the gases and cooled them down to approximately 2,000 degrees. The density and temperature allows the elements to nucleate and form solid particles large enough to survive the journey into open space. Scientists measured particles as large as around one micron, which is fairly large for grains of cosmic dust.
Source: http://www.ascensionearth2012.org/2014/07/solving-mystery-of-cosmic-stardust.html
