There are many stars in the universe, and the sun is one of them. The shape of the sun is a sphere and has a hot plasma. It is the essential source of energy and supports life on our planet earth, it has a diameter of 109 times bigger compared to the earth, whereas its mass is more than 330,000 times that of the earth. Approximately ¾ of the mass of the sun is hydrogen, while the remaining part is mostly helium and other heavy elements.The sun can be classified as a middle-aged star and has not changed much for more than 4 billion years, and it is thought to remain relatively stable for another 5 billion years. In a single second, the sun can fuse approximately 600 million tons of hydrogen to helium, and as a result of converts about 4 million tons of matter into energy.
Stars Closest to Earth
Other than the sun there are many stars located within 16 light years away from earth; these stars form stellar systems which are a group of stars that are orbiting each other. There are more than 52 stellar systems that are known so far thanks to technological improvements that have made it possible to study far away objects in the universe.
Also called the Alpha Centauri C, this is a small and relatively cool star (Red dwarf star), and its distance from the sun is about 4.25 light-years. It is located in the Centaurus constellation. The star was discovered by Robert Innes, a Scottish astronomer, in 1915. Although Proxima Centauri is closer to the solar system, it is still invisible to the naked eye.
Another extremely-low-mass red dwarf star and its distance from the Earth is approximately six light-years found on the Ophiuchus constellation. It is the closest star to the Northern Celestial Hemisphere visible from the North Pole. Barnard's Star was discovered by and named after E. E. Barnard, an American astronomer. The star is about 7-12 billion years old making it older than the Earth's sun.
Luhman 16 is approximately 6.5 light-years away from Planet Earth, and it is located in the Vela constellation. The star is about 800 million years old, and it was discovered in 2013 by Kevin Luhman, an astronomer from Pennsylvania State University.
Located in the Leo constellation, Wolf 359 is about 7.9 light years away from earth with an apparent magnitude of about 13.54. The star was discovered in 1917 by Max Wolf, a German astronomer, after whom the star was named. Wolf 359 can only be seen through a powerful telescope.
Lalande 21185 holds the unique distinction of being the brightest red dwarf star that can be observed from the Northern Hemisphere. It is located in the Ursa Major constellation, and it is about 8.31 light-years away. Lalande 21185 was spotted in 1801 by Jerome Lalande, a French astronomer.
Other stars closer to earth include Sirius which is about 8.69 light years away followed by Luyten 726-8 which is about 9.791 light-years away and was spotted in 1949. There is also Epsilon Eridani which is 10.49 light-years away and was discovered in 2000. Others include Lacaille 9352, EZ Aquarii, 61 Cygni, and Procyon among others.