Who doesn’t love a tale of estranged siblings? From the perky Parent Trap to the poorly-accented Robin Hood: Prince of Thieves, to the glorious Star Wars, the long lost sibling storyline is guaranteed to please.
Good news for our sun, because we just found its brother. Unlike Luke and Leia, the sun’s estranged solar sibling will not introduce any awkward brother/sister kissing. It could, however, give us a much better understanding of why our sun supports life. Maybe the sun’s brother even hosts alien life itself!
Stars are born in beautiful clouds called nebulae. Space isn’t homogenous, and so very gradually gravity starts acting on denser areas, pulling together all the space gunk (professionally called ‘interstellar medium’) into billows of dust. Gravity continues compressing these clouds until there is enough pressure for some of the mass to ignite, forming a star.
Each of these clouds can spawn thousands of baby suns, plus all the planets, moons, asteroids, and Rebel Bases that accompany a solar system. Eventually they wander away from the cloud and go about their lives, dying violently and spewing all their guts into space to become interstellar medium and eventually make more stars.
Our sun, known as Sol, is an incredibly ordinary star. It’s mostly hydrogen and helium, which is the sign of a healthy, yuppie sun. However, it does have trace chemicals that make it unique from other stars. Using advanced techniques to discern the chemical composition of 30 likely candidates, paired with sophisticated calculations of stars’ trajectories, a team at The University of Texas identified one star that appears to have been born out of the same nebula as our sun.
It’s the star memorably named “HD 162826.”
Unfortunate names aside, if you’re a space geek at all (or really if you’ve ever looked at the sky) you have probably stared right at our sun’s brother without knowing it. It’s very close to Vega, which is not only one of the brightest stars in the sky, but it’s the star Carl Sagan chose to have fictitiously host life in his book and movie Contact. You can’t see HD 162826 with the naked eye, but with a pair of binoculars it shows up plain as day.
The star is a little bit bigger than ours, and while astronomers are fairly certain that there are no giant Jupiter-esque bodies in its orbit, it’s possible that it could host Earth-sized planets. Incredibly, this sibling star may be the best place to search for extraterrestrial life. Whatever catalyzed life may have swapped spit with HD 162826. Or more professionally, “It is possible that spores of life have been exchanged between our Solar system and the possible planetary systems of these stars.”
Even if we perfect our Tardis and travel the 110 light years through time and space to check out Earth’s sibling, only to realize that Brother Sun is a jerk who extinguishes any planetary body or trace of alien life, hope isn’t lost. Since thousands of stars are born of the same nebula, the sun has potentially thousands of siblings sharing our life-supporting spores. Successfully identifying one solar sibling opens the doors to easily finding many more.
When Carl Sagan said, “we’re made of star-stuff,” what he really meant was that we’re made from the compacted ashes of dead stars, which makes space seem that much more lonely. But Sol found a star that started out its treacherous life from the same ashes, and though it strayed over 100 light years away, it shares the same familial idiosyncrasies.
Welcome to our dysfunctional family, HD 162826!
Images: WikiMedia Commons