The interaction of two massive stars sparked a cosmic firework that was captured by the Webb Space Telescope to form at least 17 concentric rings of dust over the past 130 years.
Including the sun, the “stellar wind (stream of charged particles)” blowing from the surface of stars to push the surrounding dust is a common sesame trivia in the universe. What is interesting is how this dust spreads into the surrounding space. And when there are two stars in a binary system that are relatively close together, the stellar winds merge to form interesting concentric rings of dust.
Astronomers had expected the dust to spread at a uniform rate, but when a team from the University of Cambridge, UK, analyzed observations of the WR140 system over the past 16 years, they found that the dust was actually accelerating as it traveled.
The WR140 system consists of an O-type star and a Wolf-Rayet (WR star) orbiting each other. The former is about 20 times the size of the sun and is a very rare star type with a surface temperature of over 30,000K; The latter is even rarer, 100,000 times brighter than Earth, with a surface temperature ranging from 30,000K to 210,000K.
▲ Wolf-Rayet and O-type stars.
The WR140 system composed of these two giant stars is a million times brighter than the sun. When the two orbits close to each other (circling once every 8 years) and interact, they blow at a speed of 3,000 kilometers per second. Stellar wind collisions also formed the oddly-shaped concentric rings newly captured by the Webb Space Telescope. Scientists knew dust shells were expanding fast, but they didn’t know it was getting faster, and new research shows that stars emit extremely intense light interacting with matter, pushing dust and accelerating it.
In the past, the Keck telescope could only photograph the first two concentric rings of the WR140 system, but the Webb Space Telescope photographed at least 17 concentric rings that spread out from the center at perfect intervals. Rings can work like annual rings to figure out how long ago the outermost ripples were formed.
Photons carry momentum that propels matter, but the process is difficult to capture, and acceleration caused by the light of stars is even rarer, because this force weakens with distance and is quickly taken over by other natural forces. The Webb telescope not only once again proved its powerful function, but also opened a new door for the study of Wolf-Rayet physics.
The new paper is published in the journal Nature Astronomy.
(Image credit: NASA)
New technological knowledge, updated from time to time