A star is a luminous body made of hot plasma by constant burning of fuel and is very important for life. But then what is the largest star?
BROWN DWARF
Brown dwarfs are substellar objects that have more mass than the biggest gas giant planets, but less than the least massive main-sequence stars. Their mass is approximately 13 to 80 times that of Jupiter -- not big enough to sustain nuclear fusion of ordinary hydrogen into helium in their cores, but massive enough to emit some light and heat from the fusion of deuterium or in simple words a nucleur reaction in the cores of the failed star.
The objects now called "brown dwarfs" were theorized by Shiv S. Kumar in the 1960s to exist and were originally called black dwarf, a classification for dark substellar objects floating freely in space that were not massive enough to sustain hydrogen fusion. This was in the olden and boring days.
These are the smallest thing closest to stars and at the start of our long table.The nearest known brown dwarfs are located in the Luhman 16 system. The image below is of a brown dwarf.
RED DWARF
A red dwarf is the smallest and coolest kind of star on the main sequence. Red dwarfs are by far the most common type of star in the Milky Way, at least in the neighborhood of the Sun. From Earth, not one star that fits the stricter definitions of a red dwarf is visible to the naked eye. Proxima Centauri, the nearest star to the Sun, is a red dwarf, as are fifty of the sixty nearest stars. According to some estimates, red dwarfs make up three-quarters of the stars in the Milky Way. Proxima centauri, Barnard Star, Trappist-1, Teegarden's Star are some examples of red dwarfs.
SUN
The Sun is the star at the center of the Solar System. It is a massive, hot ball of plasma, inflated and heated by energy produced by nuclear fusion reactions at its core.About 1.3 million Earths could fit inside the sun, according to NASA's statistics. The mass of the sun is 1.989 x 1030 kilograms, about 333,000 times the mass of the Earth. Its diameter is about 865,000 miles (1.4 million kilometers).
ALPHA CENTAURI A
Alpha Centauri A is slightly larger and more massive than our Sun, with a diameter of about 1.7 million kilometers (1.05 million miles) and a mass of 1.1 times that of the Sun. Alpha Centauri A is a Class G star that is 1.1 times the mass of the Sun.
SIRIUS A
Sirius A is the brightest star in the night sky. Sirius, brightest star in the night sky, with apparent visual magnitude −1.46. It is a binary star in the constellation Canis Major. Sirius itself has a mass two times that of the Sun and a diameter of 1.5 million miles (2.4 million kilometers).
The bright star on top is Sirius A and the dim blue star is Sirius B.
POLLUX
Pollux is the brightest star in the constellation of Gemini. Its radius is 6.1222 million km or five times of the Sun. Its mass is 4.057 × 10^30 kg. Its luminosity is 43 L☉.
ARCUTRUS
It is about the same mass as the Sun, but has expanded to 25 times its size and is around 170 times as luminous. Its diameter is 35 million kilometres. It has the mass of 2.188 × 10^30 kg.
RIGEL
It has the raidus of 54.89 million km or more than 50 times of the sun. It has the mass of 3.58 × 10^31 kg. It is in the constellation Orion.
BETELGUESE
Betelgeuse is a red supergiant star of spectral type M1-2 and one of the largest visible to the naked eye. It has the radius of 617.1 million km.
ALDEBARAN
Aldebaran is a star located in the zodiac constellation of Taurus. It has the mass 3.381 × 10^30 kg. It is 44 times the diameter of the Sun, approximately 61 million kilometres.
ANTARES
Antares has a radius of about 600 to 800 times that of the Sun. This gives Antares a diameter between 835 million to 1.114 billion kilometers in size.
UY SCUTI
It has an estimated radius of 1.188 billion kilometers. If UY Scuti were the center of our solar system, its photosphere, or outer shell, would reach just past the orbit of Jupiter.
STEPHENSON 2-18
The winner of this crazy competition is Stephenson 2-18!
Stephenson 2-18 is now known as being one of the largest, if not the current largest star ever discovered, surpassing other stars like VY Canis Majoris and UY Scuti. Stephenson 2-18 has a radius of 2,150 solar radii, being larger than almost the entire orbit of Saturn.