Astronomy: What is a Light Year?
What is a light year?
The answer is very simple! A light year is a unit of measuring the distance, especially used in astronomy. As the distances between the stars, the galaxies are very huge and it is difficult to explain them in regular units of distances, the concept of light years was introduced.
The light travels about 300,000 Kilo Meters (Exactly saying 299,792.458 Kilo Meters) per second. So when we calculate, we find that it travels 9,500,000,000,000 Kilo Meters (That is about 10Trillions Kilo Meters or 6 Trillion Miles) in a year!This distance is known as One Light Year distance.
The nearest star to us is Proxima Centauri. It is just (!) 4.24 Light Years away from us. It means, the light coming from that star reach to us after 4.24 years. In other words, this distance is about 42 Trillions of Kilo Meters.
It also means that the star Proxima Centauri we see today, is of 4.24 years before.
Who Invented The Concept of Light Year?
Many people know the concept of a light year, but few people know that Friedrich Wilhelm Bessel, a German mathematician and astronomer, was the inventor and the first user of the light year concept in 1838.
He was born 22nd July 1784. He was lacking University education. In spite of that, he became a famous astronomer of his times. He was first to use Parallax to calculate the distance to stars. At the age of 26, he was appointed as director of the Königsberg Observatory by King Frederick William III of Prussia. There he recorded positions of over 50000 stars.
The asteroid 1552 and the largest crater in the Moon's Mare Serenitatis is named Bessel after this great astronomer.
Top 10 Nearest Stars
A list of top 10 nearest stars from us.
Proxima Centauri: 4.24 Light Years
Apha Centauri A : 4.36 Light Years
Apha Centauri B: 4.36 Light Years
Barnard's Star: 5.96 Light Years
Wolf 359: 7.78 Light Years
Lalande 21185: 8.29 Light Years
Sirius A: 8.58 Light Years
Sirius B: 8.58 Light Years
Luyten 726-8 A: 8.72 Light Years
Luyten 726-8 B: 8.72 Light Years
Video: Light Years Explained0
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