Even though we see stars every day, twinkling in the night sky, they never fail to fascinate scientists and ordinary observers alike. In 2010, scientists were thrilled when they found the most massive star ever in the entire universe.
Its mass and brightness was beyond what many scientists thought was even possible. Such is an addition to an ever growing list of supergiants and hypergiants. Here are the ten largest stars in the universe in terms of mass, size, and luminosity.
R136a1 is believed to be the most massive star in the universe. In 2010, British astronomers in the University of Sheffield discovered the giant star in the Tarantula Nebula through a small satellite galaxy that circles the Milky Way.
While R136a1 is reported to be 265 times more massive than the Sun, it could have been 320 times more once, the discoverers noted. This star is also the most luminous. It is believed to be 10 million times brighter than our sun and has a temperature of 40,000 degrees Celsius on its surface. The R136a1 gives off more energy than all stars belonging in the Orion Nebula.
2. VY Canis Majoris
VY Canis Majoris is 30 to 40 times as heavy as the sun. A red hypergiant 2,000 times bigger than the Sun, VY Canis is the largest star in the universe in terms of size. To put things into perspective, if we could take VY Canis Majoris and put it in our solar system in place of the sun, it would stick out of Saturn’s orbit.
The VY Canis Majoris emits roughly 500,000 times as much light as the Sun does. Its temperature is estimated at around 3,200 degrees Celsius. The distance between this star and the Earth is 5,000 light years.
3. VV Cephei A
The VV Cephei A is one of the biggest stars found in the constellation Cepheus. It is about 5,000 light years away.
This star is recognized as a red supergiant primary as its luminosity and magnitude do not qualify it as a hypergiant. The VV Cephei A has a solar radius between 1,050 to 1,900.
This star belongs to an eclipsing binary star system called VV Cephei which is not entirely spherical, and hence, has unstable luminosity. It is also difficult to measure in terms of size.
4. Mu Cephei
Another star found in the constellation Cepheus that is among the largest and most luminous stars in the Milky Way is Mu Cephei. It is a so-called red supergiant star and may be the largest star visible to the naked eye, and possibly, in the whole galaxy.
Visually, Mu Cephei emits about 100,000 times more light than the Sun does. It takes a billion suns to match the size of Mu Cephei. It is also known as Herschel’s Garnet Star, as its deep red color was noted by William Herschel (1738-1822), a German-born British astronomer. This star is currently unstable in terms of light output, temperature, and size. It is, moreover, believed to be nearing death.
5. Pistol Star
Among the most radiant stars in the whole Milky Way galaxy, the Pistol Star measures between 80 to 150 solar masses, which means that its mass is roughly 80 to 150 times greater than that of our Sun.
First discovered in 1991 with the aid of the Hubble space telescope, this blue hypergiant was the most massive known star before the discovery of R136a1. The energy that it radiates in a matter of only 20 seconds is equal to what our sun does in a year.
It is, furthermore, believed to be 10 million times more luminous than the Sun. The Pistol Star is 25,000 light-years from the Earth and has a diameter that is significantly larger than the Earth’s orbit around the Sun.
Betelgeuse is the brightest star in Orion, and one of the largest known stars with a diameter of roughly 700 times that of the Sun.
Orion’s Alpha star is 20 times more massive than the Sun. This red supergiant emits 7,500 times as much energy as the Sun does. Its surface temperature of 6,000 degrees Fahrenheit is lower than the Sun’s 10,000 degrees. It is located 520 light years away from this planet. Stars like Betelgeuse may be close to the end of their life.
Another red supergiant within the Milky Way, Antares is the 15th brightest star in the sky. To the naked eye, it is about 10,000 times brighter than the Sun.
This bright celestial jewel has a color that can be compared to that of Mars. In fact, Antares translates to “like Mars.”Scientists estimate that it has a mass of 15 to 18 solar masses. It is quite cooler than the Sun, with a surface temperature of only 3,600 degrees Kelvin. Antares is believed to explode as a supernova anytime soon. This star is 550 light years away and shines just opposite Betelgeuse. It guides observers to the constellation Scorpius.
Rigel is a blue-white supergiant that ranks seventh in visual brightness. It is 860 light years away from Earth. This luminous star is 85,000 times brighter than the Sun, and much brighter than Orion’s Alpha star Betelgeuse. When measured, 74 Suns would fit inside Rigel. That size is nearly as big as Mercury’s orbit.
Furthermore, Rigel’s mass is about 18 times the mass of the Sun. It is currently 10 million years old and is believed to expand eventually into a red supergiant like Betelgeuse. Observers and enthusiasts should find Rigel, Orion’s Beta star, as the mythical Hunter’s foot looking down upon us.
Aldebaran, the brightest star in the constellation Taurus, matches the brightness of 425 Suns. Its name translates to “the follower,” as it seemingly follows a cluster called the Seven Sister or Pleiades.
This star has a distance of 67 light years from the earth and carries a mass that is just about twice than that of the Sun. If this star were put in our solar system, it would reach halfway the planet Mercury but its brightness will not make life possible on Earth.
Arcturus is the northern hemisphere’s brightest star. The Alpha star of Bootes constellation is 37 light years from the Earth. This orange giant star measures 4,290 degrees Kelvin at the surface.
If one looks at it with the naked eye, the star is 113 times more luminous than this solar system’s Sun. However, if the infrared radiation is taken into the equation, Arcturus should emit 215 times more radiation than the Sun does. In terms of size, it is roughly one-fourth of Mercury’s orbit, while its mass is about 1.5 times that of the Sun.