If the star HD 140283 were a dude, it would have a long white beard and would hobble around on a cane, yelling at all the other younger stars, calling them whipsersnappers and whatnot. See, this star is old, very old, nearly as old as the universe itself.
A new estimate puts the age of HD 140283 at a whopping 14.46+-0.80 billion years old, which places the star’s origins shortly after the Big Bang. That’s a lot of candles. And at 190 light years away from the sun, that puts HD is roughly in our neck of the woods, universally speaking.
Metal-poor stars like this one are important for scientists to predict the age of the universe, since metal content is a stand in for age. Heavier metals are generally formed in supernova explosions, which pollute the surrounding interstellar medium. Stars subsequently born from that medium are more enriched with metals than their predecessors, with each successive generation becoming increasingly enriched. Indeed, HD 140283 exhibits less than 1% the iron content of the Sun, which provides an indication of its ancient age.
A team, led by Howard Bond, used a computer model that tracks luminosity and temperature over the lifespan of the star, which is how they derived the 14.46+-0.80 billion-year mark.
Previous attempts to examine globular star clusters and the Hubble Constant—the expansion rate of the universe—have come up with drastically different ages for the universe. Hammering down the age of HD 140283 will allow researchers to use it in comparison to existing age estimates.
Basically, this new study confirms that there are some cranky old man stars hanging around the block. If you can get them to talk to you, they can be used to estimate the approximate age of the universe.