2021-06-05

Astronomers noticed a significant difference in the matter ejected from a massive primordial star

By yqqlm yqqlm

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Astronomers noticed a significant difference in the matter ejected from a massive primordial star

The telescope enables astronomers to perform observations on the inner regions of the material jets from massive young stars. The most detailed imaging. Low-mass and high-quality young stars, called primordial stars, eject material perpendicular to the disk of matter that orbits the star closely. For a star with a mass similar to the sun, the ejected material will be relatively tightly concentrated near the star through a process called collimation.

Most high-quality protostars are relatively far away, and it is difficult to study the regions of these stars at close range, which makes scientists uncertain whether the same process occurs in higher-mass stars. The high-quality protostar studied by astronomers is called Cep A HW2, which is about 2,300 light-years away from Earth in the constellation Cepheus. When its development is complete, Cep A HW2 is expected to develop into a star ten times the mass of the sun.

Using the very large antenna array, astronomers can collect images that show the finest details of such celestial bodies, allowing astronomers to see the innermost part of the jet. The part the team saw was approximately as long as the diameter of the solar system. The research team says that what they see is very different from what they normally see in jets of matter ejected from low-mass stars.

Astronomers noticed a significant difference in the matter ejected from a massive primordial star(1)

On low-mass protostars Observations show that the jet is collimated when approaching the star, only a few times the distance between the earth and the sun. In Cep A HW2, what the research team observed was not a single jet, but two different substances. The research team saw a wide-angle wind originating from near the star, and a jet stream gathered at a greater distance. The collimated jet from a massive star starts at a distance from the star, which is equivalent to the distance between the sun and Uranus or Neptune.

The team said that two things may be at work. First, although the same mechanism can work in high- or low-mass protostars, the mass of the star can determine the collimation distance. The second possibility is that high-quality stars may only produce the wide-angle winds observed in Cep A HW2, and collimation can only be caused when the physical conditions around the star restrict the flow of the jet.