The Biggest Known Stars in the Universe: Exploring UY Scuti, Stephenson 2–18, and Beyond

For years, the quest to discover the largest and most massive stars has piqued the interest of astronomers and enthusiasts alike. As of August 2023, UY Scuti stands tall among these cosmic giants with its impressive radius, dwarfing even the Sun. But is UY Scuti truly the largest star we know of, or are there even more massive stars waiting to be discovered?

Diameter and Radius of UY Scuti

UY Scuti, a red supergiant located in the constellation Scutum, holds the title of the largest known star by radius, with an estimated diameter of around 1,700 times that of the Sun. If the Sun were the size of a marble, UY Scuti would be roughly the size of a 10-story building! This colossal star is a true behemoth in the heavens, shining with a luminosity 340,000 times brighter than our Sun. Its enormous size is reflected in its volume, estimated to contain nearly 5 billion Suns.

Mass of the Most Massive Star

In terms of mass, the most renowned candidate is Wolf 359, a Wolf-Rayet star. Estimate its mass ranges from 100 to 150 times that of the Sun. However, these estimates can vary significantly due to the complexity of measuring such distant and massive stars accurately.

While Wolf 359 holds the title of the most massive, the accuracy of these measurements is subject to ongoing research and advancements in observational techniques. As new data and technologies become available, these figures are expected to evolve, potentially revealing even more massive stars in the future.

Stephenson 2–18: A New Record Setter?

The latest contender in this endless cosmic competition is Stephenson 2–18, a star system that has recently outstripped UY Scuti as the largest known star. With a radius ten times that of the average distance between the Earth and the Sun, Stephenson 2–18 surpasses even the previous record holder, UY Scuti. Although its mass is not yet confirmed, it has the potential to fit an astounding 8 billion suns or 13 quadrillion Earths within its vast expanse.

While Stephenson 2–18 currently holds the title of the largest star discovered, the cosmic frontier remains vast and full of mysteries. Who knows what other supergiants or hypergiants may be waiting to be discovered in the depths of space?

Other Notable Stars

Several other stars compete for attention in the title of the largest known star. VY Canis Majoris and WOH G64 are two notable contenders, both hypergiant stars located at impressive distances from Earth. VY Canis Majoris boasts a diameter estimated at around 1,420 times that of the Sun, while WOH G64, comprising two significantly larger than the Sun, is a fascinating binary system.

Conclusion

The search for the largest known stars continues to captivate astronomers and inspire awe. With new observational techniques, advances in technology, and the vastness of the universe, it's entirely possible that even more massive stars may be discovered in the future. UY Scuti, Stephenson 2–18, and other contenders remain at the forefront of this quest, each one a testament to the boundless wonders of the cosmos.