Which is the biggest star in the Universe discovered so far?

Stars vary greatly in size and brightness. While our Sun is considered an average-sized star, astronomers have discovered stars that are hundreds to thousands of times larger. The biggest star known so far is UY Scuti, a red supergiant located about 9,500 light-years away in the constellation Scutum.

UY Scuti is classified as a hypergiant and is considered the largest star by radius (volume). Its radius is estimated to be 1,700 times bigger than the Sun’s. If UY Scuti were placed at the center of our Solar System, its outer layers would extend beyond the orbit of Jupiter, swallowing Mercury, Venus, Earth, Mars, and even the asteroid belt.

Let’s analyze the options:

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  Rigel: A bright blue supergiant in Orion, very luminous, but not the largest by size.

  
  


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  Canopus: The second brightest star in the night sky, but smaller compared to UY Scuti.

  
  


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  Arcturus: The brightest star in the northern hemisphere, but also much smaller than UY Scuti.

  
  


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  UY Scuti: Correct answer. The largest star discovered so far.

  
  

Interestingly, UY Scuti is not the most massive star (stars like R136a1 are more massive), but it is the largest in terms of volume. Its brightness also changes because it is a variable star, meaning its luminosity fluctuates over time.

The discovery of such stars helps astronomers understand stellar evolution — how stars form, grow, and eventually die. UY Scuti, being a supergiant, will eventually end its life in a massive supernova explosion, possibly leaving behind a black hole or neutron star.

In summary, the biggest star discovered so far is UY Scuti (Option A). Its sheer size and distance make it one of the most fascinating objects in our universe.