Life on our entire planet depends on the Sun, and sometimes we do not realize that in fact there are many other galaxies in the Universe and star systems inside them. And our almighty Sun is just a small star among billions of other luminaries. Our article will tell you the name of the largest star in the world, which can still be covered by the human mind. Perhaps, beyond it, in hitherto unexplored worlds, even more gigantic stars of immense size exist …
Measure stars in Suns
Before talking about the name of the largest star, let's clarify that the size of stars is usually measured in solar radii, its size is 696,392 kilometers. Many of the stars in our galaxy are larger than the Sun in many ways. Most of them belong to the class of red supergiants -large massive stars with a compacted hot core and a rarefied envelope. Their temperature is noticeably lower than the temperature of blue and white stars - 8000-30,000 K (on the Kelvin scale) and 2000-5000 K, respectively. Red stars are called cold, although in fact their temperature is slightly less than the maximum temperature in the core of our Earth (6000 K).
Most celestial objects do not have constant parameters (including size), but rather are in constant change. Such stars are called variable - their sizes change regularly. This can happen for various reasons. Some variable stars are in fact a system of several bodies exchanging masses, others are pulsating due to internal physical processes, shrinking and growing again.
What is the name of the biggest star in the universe?
At a distance of 9.5 thousand light years from the Sun is the constellation of the Shield. It appeared on star maps at the end of the 17th century, thanks to the Polish astronomer Jan Hevelius. And two hundred years later, German astronomers from the Bonn Observatory added the star UY Shield (U-Ygrek) to the catalog. And already in our time, in 2012, it was found that UY Shield is the largest of the known stars within the studied Universe.
The radius of the UY Shield is about 1700 times greater than the radius of the Sun. This red hypergiant is a variable star, which means its size can reach evenlarger sizes. During periods of maximum expansion, the radius of the UY Shield is 1900 solar radii. The volume of this star can be compared with a sphere, the radius of which would be the distance from the center of the solar system to Jupiter.
Giants of Space: what are the names of the biggest stars
In the neighboring galaxy the Large Magellanic Cloud is the second largest star within the studied space. Its name cannot be called particularly memorable - WOH G64, but you can take note that it is located in the constellation Dorado, a constant visible in the southern hemisphere. In size, it is slightly smaller than UY Scutum - about 1500 solar radii. But it has an interesting shape - the accumulation of a rarefied shell around the nucleus forms a spherical shape, but rather resembles a donut or bagel. Scientifically, this shape is called a torus.
According to another version, what is the name of the largest star after UY Shield, the leader is VY Canis Major. It is believed that its radius is equal to 1420 solar. But the surface of VY Canis Majoris is too rarefied - the Earth's atmosphere exceeds it in density by several thousand times. Due to the difficulty in determining what is the actual surface of the star, and what is already its companion shell, scientists still cannot come to a final conclusion regarding the size of VY Canis Major.
Heaviest stars
If we consider not the radius, but the mass of a celestial body, then the largest star is called as a set of letters and numbers in encryption - R136a1. It is also located in the Large Magellanic Cloud, but it belongs to the type of blue stars. Its mass corresponds to 315 solar masses. For comparison, the mass of the UY Shield is only 7-10 solar masses.
Another massive formation called Eta Carina is a giant double star in the constellation Carina. In the 19th century, an outburst created a nebula around this system, named Homunculus because of its strange shape. The mass of Eta Carina is 150-250 solar masses.
The biggest stars in the night sky
Hiding in the depths of space, giant stars are inaccessible to the eye of a simple layman - most often they can only be seen through a telescope. At night, in the starry sky, the brightest and closest objects to the Earth will seem large to us - be it stars or planets.
What is the name of the biggest star in the sky and at the same time the brightest? This is Sirius, which is one of the closest stars to the Earth. In fact, it is not much larger than the Sun in size and mass - only one and a half to two times. But its brightness is really much greater - 22 times greater than that of the Sun.
Another bright and therefore seemingly large object in the night sky is actually not a star, but a planet. We are talking about Venus, the brightness of which in many respects exceeds the rest of the stars. Its brilliance is visible closer to sunrise or some time after sunset.
