The last gases of dying stars are the most beautiful objects in the galaxy.
They are called planetary nebulae, clouds of stellar objects that are emitted into space when a red giant star enters the last phase of its life. The dying star shakes its outer layers, which glow from the inside with a hot, exposed center.
These clouds are complex, beautiful, like mandala-like waves, strange disks, wing-like pilot jets. The stunning complexity of these shapes and the variety contrast with the uniform shape of their predecessor stars.
“The sun – which eventually turns into a red giant – is like a billiard ball, so we wondered: how could such a star create these different shapes?” Said Leon Tesin, astronomer of KU Louvain in Belgium.
Now, with a comprehensive set of observations and hydrodynamic simulations, scientists have discovered how planetary nebulae can take on their forms: gravitational interactions with binary star companions and large planets such as Jupiter escaping the violent death of their host stars.
Initially, the team did not see the planetary nebula. The focus of their research was on a slightly earlier life stage, called the symptomatic giant branch (AGP).
When the red giant is in the final stages of evolution before the planetary nebula phase, and powerful winds from the star blow out into space around it, scattering gas and dust.
Red giants are the aging age of a particular type of star, which is less than eight times the mass of the Sun. How the sun is going to end its life, drowning Mercury, Venus and even Earth.
So, how these stars die is very interesting to astronomers. Yet DeGeneres ‘international team found that a comprehensive database of observational data on the AGP stars’ air had not been compiled. So they set out to create one.
“In the absence of such detailed observational data, we initially assumed that stellar winds had an overall spherical geometry, similar to the stars around them,” said Carl Godlip, an astronomer at the Harvard-Smithsonian Astronomical Center.
“Our new observational data shape a very different story of individual stars, how they live and how they die. We now have an unprecedented view of how stars like our Sun form in the final stages of their evolution.”
Using the Atacama large millimeter / sub millimeter array in Chile, the team observed a sample of AGP stars. In that data, they observed many structures, including curves, shells, bipolar structures, clamps, coils, donut shapes, and rotating disks.
The team quickly discovered that something in the immediate vicinity of the star could cause the structures of the object – such as a small binary asteroid or giant planet – to appear very dizzy, but whose gravitational pull would affect the object, as the radioactive exhaust air was uniform.
Indeed, while modeling the effect of a comrade on these expressions, the team found that every type of structure they observed could be created by the presence of a secondary object. The mass of the object, its distance from the star, and the eccentricity of its orbit may all play a role in the various structures produced in stellar air.
“You can stir a little milk into a cup of coffee and create a spiral shape with a spoon so that the mate will suck the material towards it as it spins around the star and forms stellar air,” Desin said.
“All of our observations can be explained by the presence of a subset of stars.”
All shapes have strong similarities with the complex structures and shapes found in planetary nebulae, suggesting that the structures at both levels have the same formation mechanism. There are a wide range of implications for our understanding of stellar evolution.
“Our findings change a lot,” Desin said. “Since the complexity of stellar winds has not been calculated in the past, the previous mass-loss rate estimate of older stars may be as high as 10 factors.”
This finding also strongly points to what can happen when the sun dies. For our sun, there is definitely no binary support (this is also a bit of a mystery).
But there are two planets in the solar system. They are Jupiter and Saturn, the gas giants, whose mass is already large enough to pull the sun into a small swaying circle.
When our star turns into a red giant they cannot reach the sun, and recent discoveries suggest that giant planets can actually escape the death of their stars – perhaps not for long, but for a long time to form some waves (or curves or bombs).
The team’s calculations predict that Jupiter, and Saturn will be able to carve relatively weak scrolls in the Sun’s AGP wind.
The team is now conducting further research to find out what else their discovery might change for our understanding of the deaths of stars.
Research has been published Science.