A team of researchers from Kagoshima University in Japan and the Chalmes University of Technology in Sweden used the ALMA telescope to observe the aging star W43A and successfully mapped the distribution of the jet from the star and its surroundings. According to a detailed analysis of the data, jet squirting began 60 years ago. The results reveal the mechanisms of the formation of the Planetary Nebula.
Stars of mass similar to the sun will expand into red giants in the final stages of their lives, becoming “planetary nebulae”. The Planetary Nebula has shapes of spherical, slender and so on. Since the underlying star is spherical, the mechanism of the emergence of various shaped nebulae has attracted the attention of many astronomers.
The shape of the Planetary Nebula depends on whether the original star is a single star or a binary star. The gas of a single star is basically spherically symmetrical, so the shape of the Planetary Nebula is also spherically symmetrical. In the case of two stars orbiting each other, the gas ejected from the aging star is affected by the gravity of another star, forming a complex shape of an asymmetric sphere.
Planetary nebulae are obscured by material released by stars, making it difficult to observe directly.
Using the high-resolution ALMA telescope, the team observed W43A, one of the “cosmic fountains”, successfully capturing radio waves from the jet stream of an aging star and capturing its distribution of dust. W43A is a co-star in the direction of the constellation Ofshawk, about 7,200 light-years from Earth.
A detailed analysis of the data by the team found that the jet speed from the celestial body reached 175 km per second, much higher than previously estimated. The reversal of jet length and velocity suggests that jet currents only started erupting 60 years ago. In addition, it is confirmed that gas clumps arranged almost equally spaced in the jet stream are confirmed.
“Both the jet stream and the planetary nebula that formed in the next few decades are part of the rotation of matter between interstellar space and stars,” said the team’s leader, Professor Yukio Ishii of Kagoshima University. By observation, we see the process by which elements synthesized inside stars are scattered through space. Uncovering its mechanisms gives us a deeper understanding of the evolution of cosmic matter. “
The findings were recently published in Astrophysical Letters.