Mike Myers, age 14, of Gladstone, Ore
How many light years away is the nearest star?
A light year, of course, is the distance traveled by a beam of light in one earth‑year, The speed of light is about 186,000 miles a second, which makes the distance of a fight year equal to about six million , million miles That is figure six, followed by 12 zeroes The sun is a star, but it is only 92 million miles away from us Its light distance is merely eight minutes, the time it takes for its light to reach us All the other stars we see are years away, in terms of light
North of the equator, the nearest star we see is Sirius, the Dog Star This brilliant carbuncle follows the dazzling constellation of Orion over our winter skies It is the most brilliant star seen from anywhere on earth Sirius is at a distance of 8 6 light years, or about 50 million, million miles When we look at the Dog Star, we are seeing light which set out towards us more than eight and a half years ago
In the skies above the southern hemisphere, there are three stars at a distance of about 4,4 light years The three are part of a starry unit, orbiting about each other Two of them era bright enough and close enough together to be seen as a single star of first magnitude We call them a double star The fact that they are two stars can be detected only through a telescope This double star is Alpha Centauri, the star of first importance in the constellation Centaur near the famous Southern Cross
The third member of this starry unit is too dim for our eyes to see at all The telescope shows it to be a small red dwarf star at an immense distance from the two bright stars Slowly, slowly it revolves in a vast orbit around them
Alpha Centaurs, our nearest stellar neighbor, is a multiple star system At the present time, the star nearest to our Solar System is the red dwarf revolving around the‑two bright central stars For this reason, the little dwarf has been named Proxima, meaning near one As it revolves, its path will someday take it on the far side of its bright sisters, and Proxima will no longer be the star nearest to us.
The distance of Proxima is about 4 1/4 light years or roughly 25 million, million miles The light which reaches the telescope from this nearest star set out to keep its rendezvous with earth four and a quarter years agog Proxima cannot be seen without a telescope, but its sisters are seen as a single bright star in the southern skies This double star also can be seen as far north of the equator as Florida and parts of Texas