Planetary nebulae are just a few of the many types of nebulae that exist throughout the universe. Nebulae are formed by dust and gas at high temperatures in space
They are also among the most beautiful types of nebulae, due to their psychedelic patterns. In addition, they are described by some people as "cosmic mandalas".
Although they are called planetary nebulae, they have nothing to do with planets. It was actually a mistake. Some centuries ago, during the first observations, they looked like the gas giants of the solar system. However, this was because the telescopes were not close enough.
Now, in a study published on Friday (18) in the journal Science, scientists describe the possible means by which they acquire these beautiful shapes.
They form from red giants. A red giant is a dying form of stars similar to the Sun - that is, one of the last life stages of such stars.
When the Sun loses almost all of its fuel, it will swell and turn extremely red. In the process, the Sun will grow so large that it will swallow the Earth.
In various stages of growth and decrease, it loses almost all its mass. This released gas and plasma will form the planetary nebulae, which will glow from the residual heat of the matter.
"The Sun - which will ultimately become a red giant - is round like a billiard ball, so we wondered: how can such a star produce all these different shapes?" said astronomer Leen Decin in a statement .
Computer simulations and unprecedented observations made with the ALMA observatory in Chile have helped scientists understand a little about the formation of these nebulae.
The main influences on the shape of these stars are in gravity. The gravitational pull of nearby stars and large planets like Jupiter are able to distort the gas cloud.
The main advantage of the observations they made, is for the fact that they were meticulously thought out. When you do a broad analysis with several previous observations, from other studies, however, each observation has a different method.
In this case, all observations used the same methods. This is important for the removal of biases and, therefore, a better use of the data.
More specifically, they observed stellar winds. Although they carry that name, they are not like wind. They are plasma and highly charged particles released by stars.
"We noticed that these winds are anything but symmetrical or round. Some of them are quite similar in shape to planetary nebulae," as Decin explains.
"Some stellar winds were disk-shaped, others contained spirals, and in a third group we identified cones," he says.
Exe explains that "Just as a spoon you mix in a cup of coffee with some milk can create a spiral pattern, the companion sucks the material toward it as it spins around the star and shapes the stellar wind."
In the case of the solar system, for example, there is no binary companion for the Sun. However, Jupiter and Saturn have enough mass to influence these flows considerably. One day, therefore, we will be a beautiful planetary nebula.
The study was published in the journal Science . With information from Science Alert and KU Leuven News .