What is the most massive known star by mass in the universe?

The most massive known star in the universe is R136a1, a star located in the Large Magellanic Cloud, a satellite galaxy of the Milky Way. R136a1 has a mass of around 265 times that of the Sun, making it significantly more massive than any other known star. It was discovered in 2010 using observations from the Hubble Space Telescope and was previously believed to be two separate stars.

R136a1 is a part of a cluster of stars known as R136, which contains several other massive stars. These stars are all relatively young, with ages of only a few million years, and are extremely bright, with R136a1 being one of the brightest.

The most massive known star by mass in the universe is R136a1, which is located in the Tarantula Nebula in the Large Magellanic Cloud, a dwarf galaxy satellite of the Milky Way. R136a1 has a mass of between 170 and 230 times that of the Sun. It is a blue supergiant star, and it is one of the hottest and brightest stars known. It is also one of the youngest stars known, with an estimated age of only 2 million years. R136a1 is so massive that it will only live for a short time. It will eventually collapse and explode in a supernova, scattering its material back into the interstellar medium.

Here are some other details about R136a1:

• It is about 160,000 light-years from Earth.
• It has a surface temperature of about 40,000 degrees Celsius.
• It is about 30 times the radius of the Sun.
• It is about 10 million times more luminous than the Sun.

R136a1 is a very rare object. There are only a handful of stars known to be more massive than R136a1. These stars are found in the most massive star clusters in the universe.