Is the largest known star shield from the Milky Way? Are there bigger ones in other galaxies?

Yes, UY Shield is a member of the Milky Way, and this is a red Supergiant star. I don't know if there are other galaxies bigger than it, but I believe there will be, because there are many galaxies bigger than the Milky Way, and bigger ones should exist, but we haven't found that the universe is so big that anything is possible.

UY is actually a red Supergiant star, which is very big, equivalent to 4.5 billion times of the sun. Big doesn't mean its quality is big. On the contrary, its mass is very small relative to itself, only 32 times that of the sun, which is equivalent to 3.3 million earths compared with the earth. This also shows that its density is very low and it is a gaseous star. But its brightness is very high, and the apparent magnitude is 1 1.2 to 13.3. Its brightness is 340,000 times that of our sun. At the same time, it is also a variable star, and its brightness changes periodically, with a change period of almost 740 days.

The shield constellation UY is one of the largest stars, with a huge volume, 4.5 billion suns and 200 million earths. Its diameter is over 2.37 billion kilometers, which is about 1400 times the diameter of the sun. Even if the speed of light is so fast, it will take more than 9 hours to go around. Light travels around the earth seven and a half times in 1 second. Look at the huge gap. UY is very unstable because of its large volume and extremely low density, and its quality is rapidly losing, so its life will not be too long.

Scientists estimate that its life span may be only 6.5438+million to 50 million years, after which it will eventually collapse into a black hole like other massive stars.