This Tuesday (14), NASA and the European Space Agency published an image of the star WR 124, which appears in unprecedented detail captured by the instruments of the James Webb Telescope. The star is about 15,000 light-years away from us, and was one of the first objects observed by the telescope during the beginning of its operations, in June last year.
WR 124 is of the Wolf-Rayet type, a group that includes some of the most luminous, massive, and shortest-lived celestial bodies we know of. As they move through their evolutionary cycles, massive stars briefly go through the Wolf-Rayet phase, in which they shed their outer layers; then they explode in supernovae.
This process appears in the photo of the star. It is 30 times the mass of the Sun and, so far, has expelled 10 solar masses of material. As the ejected gas moves away from it and cools, it forms dust that glows in infrared light.
Check out:
With the NIRCam instrument, the James Webb Telescope was able to balance the brightness of the star’s core and the details of the tangled gas around it; the MIRI instrument reveals the structure of the gas and the surrounding dust nebula. That’s why this photo preserves a brief but turbulent moment of transformation in the star’s “life”.
In addition to the layers of gas and dust, there are a number of stars and galaxies in the background. These structures reveal a lot about the process of mass loss: instead of having a smooth shape, this nebula was born of random and asymmetric ejections, accompanied by clumps of gas and dust pushed by the stellar wind.
After the mass loss stage, it will reach the supernova stage. That’s when it stops performing nuclear fusion in its core; with that, gravity causes the star to collapse in on itself and then explode. With the Webb data, astronomers can investigate how much dust is generated before a supernova and how much of it can survive the explosion.
The origin of the dust present in the universe, which adds to the other existing reserves, is of interest to astronomers for a number of reasons; after all, it is dust that protects forming stars, accumulates to form planets, and serves as platforms for different molecules to assemble, like those that formed the building blocks for life on Earth.
Furthermore, stars like WR 124 are like analogues capable of helping astronomers better understand the early universe. When it was in its “infancy”, stars nearing the end of their lives produced and shed heavy elements in their cores; these elements are common today and are even present on our planet.
Source: NASA
