Billions of years ago when our sun was a brand new ball of gas, it was surrounded by countless siblings. Over the years, the family drifted apart. Scientists have been trying to organize a reunion, and they’ve finally made some headway with the relatives.
Stars In A Cradle
For a star to be born, in most cases, another star must die. A dying star sheds layers of gas and dust. Those materials combine with heaps of energy to form a tightly-packed ball of matter. Inside that sphere, pressure and temperatures are so high that atoms are smashed together to make more massive particles, releasing incredible amounts of energy in the process. Once that process of nuclear fusion begins, a star is officially born.
Most stars form in stellar nurseries called nebulae. Each nebula has the potential to give rise to anywhere from dozens to hundreds of new stars. When all the dust and gas in the nebula is used up, the neighborhood of stars that are left is called an open cluster. Ever moving, the galaxy eventually pulls most of these stars apart with the interstellar tides. That’s precisely what happened to our sun over the last 4.6 billion years.
Searching For Siblings
Our sun is a main sequence star, in the prime of its life. To use its technical designation, it’s a G2V yellow dwarf. This odd classification organizes the star’s temperature, color, mass, size, and age into one convenient package. Scanning all the stars in our sky to find those that match our sun’s age and composition is a lot to ask. The fact that the search team managed to find a star that not only ticked those two boxes but is a near-identical twin is almost unthinkable.
HD186302 is a G3V type star with the same age and makeup as our sun, which means the only thing that differentiates the two of them is a slight difference in color. Studying the newly-found sibling can help astronomers learn a lot more about our sun’s past. It’s a subject about which we know surprisingly little.
A Complete Match?
Further analysis of our stellar twin will reveal whether or not the new star has planets. Ever-hopeful, astronomers are keeping their fingers crossed that they find a rocky planet within a stable, habitable orbit around our twin sun. If there is, the potential for life gets a whole lot more exciting. Theoretically, seeds of life could have hopped from our solar system to the new system during their formative years.
While the hope for life around the new star is a stretch, any planets orbiting this Sun 2.0 would provide just as much information as studying the star itself. Now, we have an example of a strikingly similar ball of gas to our own that was formed in the same place at the same time out of the same stuff. Scientists can examine the variables that caused the two to develop differently. With any luck, it’ll help us learn more about where we came from.