Check out that extra-bright galaxy towards the top of this image. That's an elliptical galaxy, which are among the largest galaxies in the universe. And now scientists believe these galaxies hold five to ten times more stars than previously thought.
Until recently, astronomers believed elliptical galaxies contained around a trillion stars each, as compared to 400 billion stars in our own galaxy. But thanks to new data, they now believe elliptical galaxies actually contain five trillion to ten trillion stars, and that by itself means the universe would have three times as many stars as we'd previously believed. (Nobody knows how many stars that is — earlier estimates were in the neighborhood of 100 sextillion, or a 1 with 23 zeroes — this discovery could mean that number is tripled.)
Astronomers used the powerful instruments at the Keck Observatory in Hawaii to detect red dwarf stars in eight elliptical galaxies, located between 50 million and 300 million light years away. Until now, we've never been able to detect red dwarfs in galaxies outside our own, because they're dim compared to stars such as our own sun. And it turns out red dwarfs are way more common than we'd previously believed, with the elliptical galaxies containing around 20 times as many of them as our own galaxy. Red dwarfs could turn out to make up 80 percent of all stars in the universe. The abundance of red dwarfs could mean there's less "dark matter" than we'd previously thought, since these red dwarfs could account for a lot of the universe's missing mass.
And yes, the abundance of these stars could mean many more Earthlike planets, which could potentially contain alien life. "There are possibly trillions of Earths orbiting these stars," Pieter van Dokkum, an astronomer at Yale University, told Space.com. [Space]