The third-closest star system to the earth has just been discovered, according to astronomer Kevin Luhman of Penn State University, who was working with NASA to create a sky map of nearby stellar objects using the Wide-field Infrared Survey Explorer (WISE). As you might expect of so-called stars that have gone unnoticed until well into the 21st century, they are small and dim. The so-called brown dwarfs are actually a double star that orbit each other about 6.5 light years away from Earth.
Since electromagnetic transmissions like television also travel at the speed of light, that means that “Earth’s television transmissions from 2006 are now arriving there,” Luhman explained.
Despite speculation that brown dwarfs may have earth-sized planets in their orbit, it may be stretching a point to call it a star system. Many experts describe brown dwarfs as too big to be planets and too small to be stars. Although they can be up to 80 times the size of our solar system’s largest planet, Jupiter, they are not big enough to undergo the fusion process that allows stars like our sun to shine.
However, they are definitely dwarfs, not dwarves. Tolkien popularized the latter word in his fantasy fiction classics The Hobbit and The Lord of the Rings, but astronomers always call the plural of the space objects “dwarfs.”
Whatever you want to call them, Luhman said that he had to use detective work to find them. He studied time-lapse digital images of the sky, comparing how it changed over time. When he noticed something that appeared to be moving very fast, he realized that it had to be close. He double-checked his work on the Gemini South telescope on Cerro Pachón in Chilé and was thrilled to discover that it was not one but two brown dwarfs orbiting each other.
This video from NASA explains how the Wide-field Infrared Survey Explorer (WISE) is used to seek out brown dwarfs in our neighborhood.
Perhaps it’s just as well that the newly discovered system is too heavy, cool, and dark for life as we know it. I’m not ready to hear what the Space Brothers from one of our closest stars would have to say about 2006 TV hits like Big Love and Dexter.
[photo courtesy NASA/ESA and K. Luhman]