A familiar collection of stars has begun forming a stellar structure, or maybe it always has been a stellar structure. The universe is keeping scientists very occupied, and just as soon as they think they have understood the anomalies of space, they get bombarded with another mystery to solve. Due to close observations, researchers discovered it is so unexpectedly large that it changes the understanding of how stars group and evolve together.
Stellar structure that challenges the current information on the universe
The Northern sky consists of a popular collection of stars that people have admired for many years. These stars are collectively called the Pleiades but are more commonly known as the Seven Sisters. Astronomers thought of it as a small group of stars that was kept together by gravity; however, this theory has been overturned entirely. It has been proven to be about 20 times larger than the structure was originally thought to be.
This discovery wasn’t made by searching deep into space, but through studying the behaviour of stars more closely. Thousands of stars were observed in terms of their rotation speeds and light patterns by scientists who were located close to the sisters. Astonishingly, researchers revealed that there were many stars around these sisters and that the star structure was not growing (as in increasing), they were separating.
Modern space technology revealed the actual size of the Pleiades cluster of stars.
In this discovery, a space craft that was originally designed to research exoplanets, called NASA’s TESS spacecraft, played a key role in revealing this structure’s true size. Using observational data, TESS can detect any changes in starlight and can reveal how fast a star rotates. Scientists found that stars existed far beyond the visible cluster that rotate nearly at the same rate as the Pleiades core, which is evidence that they share the same origin.
To be certain that the surrounding stars and the Pleiades core shared the same origin, researchers combined the knowledge that they had of the stars with that of the precise measurements from the European Space Agency’s intel that they had from the Gaia mission. The mission tracked the motion and position of billions of stars, and together, the data from the mission and the TESS spacecraft were able to prove that there were thousands of stars that were part of the same main cluster based on similar speed and direction.
A discovery that changes the way researchers study star clusters
The stars also underwent chemical analysis to make sure that the researchers’ findings were solid, and even though it just served as another layer of confirmation, when the results came back, they could proudly stand next to their research. The stars all contained a matching mix of elements such as magnesium and silicon. This served as a pattern and a recognizable chemical fingerprint. Proving the stars were born from the same cloud of gas and dust.
By uncovering the true theory of the star clusters, this has given scientists an opportunity to truly understand the life cycles of star clusters and how they behave in groups. The Pleiades are actually a young group of stars compared to the many out in the galaxy, and they have also become a foundation for discovering other star families that have already drifted apart, making them hard to recognize.
The secret behind the formation of clustered stars
Although the mystery behind the clusters’ growing formation was revealed, there is still a lot to learn about the universe. Now it is known that the story of the Seven Sisters was much broader in reality and much more detailed. This updated version of the stars gives scientists and future researchers an understanding of the lifecycle of star clusters, how they break apart, and how they evolve, allowing scientists to possibly uncover more clusters that have drifted.