Exploring the Largest Star in the Known Universe
In the vast expanse of the cosmos, daunting questions about the largest and most immense celestial bodies arise continually. Once UY Scuti was the honorably recognized largest star in our Milky Way galaxy, but now it is Stephenson 2-18 that holds the title. This article delves into these fascinating stars, their characteristics, and the scale of the universe in which they exist. If you need any convincing about the immensity of the cosmos, read on to better understand the largest star in the universe.
Introduction: Vastness of the Universe
Our understanding of the universe is a mere fraction of its entirety. We know significantly less about the Milky Way galaxy compared to what we know about the Earth. Graphic statements such as, “Our knowledge about the Earth is a mere 10, about the Solar System is 1, about the Milky Way galaxy is 0.0000001, and about the universe is 0.0000000000001,” illustrate the minuscule amount we truly know. While the universe is predicted to be billions of light years in radius, we have only a fraction of a percent of it mapped out. This realization is both humbling and intriguing.
Context and Perspective
Imagine the universe as a grain of sand on a beach, or even multiple grains combined. The vastness and infiniteness of space are infinite, while the finite universe is akin to a speck in that vastness. Trillions of stars, septillions of planets, and myriad other celestial bodies exist within this grain-sized universe. Despite our advancement, the size and scale of the universe are incomprehensible to the human mind.
UY Scuti: The Largest Star in the Milky Way
Speaking of the largest star in the Milky Way galaxy, UY Scuti reigned supreme. This red supergiant boasts a dust-enshrouded, bright red appearance and is classified as a semiregular variable with an approximately 740-day pulsation period. Its colossal radius is 909 times that of the Sun, with a luminosity 124,000 times greater than our star. With a temperature of 3,550 Kelvin, it stands at a distance of 5,871 light years from Earth. While this star holds the title for the largest in the Milky Way, it might not be the largest discovered to this day.
The Current Record Holder: Stephenson 2-18
The current record holder for the largest star in the known universe is Stephenson 2-18 (St2-18). Located in the constellation Scutum, this star is a red supergiant and the current record holder. One of its alternate names is RSGC2-18. St2-18 has been measured to be 2,150 times larger than our Sun, making it an astounding and awe-inspiring celestial body.
St2-18’s Dimensions
Just how vast is St2-18 in comparison to terrestrial and cosmic scales? Imagine Earth’s fastest jet flying around the star—it would take over 500 years. At the speed of light, it would take almost 9 hours to orbit it. Its circumference is approximately the size of Saturn's orbit. St2-18 is located 18,900 light years from Earth and is a member of the open cluster Stephenson 2.
Uncovering Star Composition and Distance
Due to the vast distances in space, it is nearly impossible to accurately determine the composition, size, and distance from Earth’s surface of stars in the sky. Ongoing research and observation methods continue to refine our understanding of these gigantic celestial bodies. While much of the data is based on estimation and theory, continuing advancements in telescopic technology and data analysis are providing us with more accurate and detailed insights into the universe's largest stars.
Conclusion: Realizing the Scale of the Universe
While the universe may seem tyrannically vast and obscure, the pursuit of knowledge is ongoing. Whether it’s UY Scuti or Stephenson 2-18, these giants of the cosmos are excellent examples of the universe’s record-breaking celestial bodies. Understanding the immensity of the universe and the magnificence of its largest stars continues to inspire wonder and deepen our appreciation for the cosmos we inhabit.