“The skies are painted with unnumbered sparks,” wrote William Shakespeare. “They are all fire, and every one doth shine.”
But the Bard didn’t know about brown dwarfs. Too big to be planets yet too small to be stars, astronomers often call them “failed stars.” And there are billions of them in our galaxy.
Stars like the Sun shine by fusing atoms together in their hot interiors, which releases energy in a blaze of light. Brown dwarfs, on the other hand, are too puny to ignite the fiery furnace of fusion. They radiate the feeblest of glows almost like an afterthought, growing cooler and dimmer with time.
It’s easy to feel sorry for brown dwarfs. Stuck somewhere between stars and planets, they’re the overlooked denizens of the night. The human eye can see thousands of stars but not a single brown dwarf. To glimpse their faint light requires large telescopes, and even then, it’s not easy – the first brown dwarf wasn’t spotted until 1994.
But there’s no shame in leading a less luminous life. Not everyone wants to be a star.
We live in an age when it’s often assumed that a happy life ...