the twisted birth of a binary star system

Scientists Just Witnessed the Birth of Two Stars in Stunning Detail

This transfixing image features two circumstellar disks in which baby stars are growing, taking in material from their surrounding disk. This is the first time ever that we’ve witnessed the complex birth of binary stars in such vivid detail. Stars are one of the most fundamental building blocks of space, but the specific conditions under which they assemble remain elusive.



How stars are formed

This is why scientists are hoping that these new observations will shine a light on their mysterious origins. So, here’s what we do know about how stars form. And no, it doesn’t involve finding an amazing agent or scoring a spot on a hit TV show after years of dead-end auditions. A star’s life begins inside a densely packed cloud of interstellar gas and dust. These clouds are made up of various elements—mostly helium and hydrogen—and are extremely cold.

This causes their resident atoms to huddle together in clumps, which buckle under their own weight once they reach a certain density. This collapse leads to fragmented clumps of matter, which now, broken free from the cloud core, can take shape into a star. Young stars are very impressionable and experience pressure coming at them from all different directions.





Gravitational pressure gets the star’s core hot enough for fusion reactions to begin, while the star’s hot, unpredictable interior results in a huge outflow of energy that helps to keep it from imploding. When the forces that push and pull on the star are in balance, it becomes a stable adult. Very relatable. While stars mostly form in the same way, they take on all different kinds of identities, from white dwarfs to blue giants. Most stars are classified by their luminosities and colors, which can shift throughout their life as they grow and age Stars are also defined by their social status.



With regard to our sun star

Our star, the Sun, is the sole provider of Earth’s light and entertainment, but most stars roll with a crew, belonging to systems where two or more stars are gravitationally bound to one another. While there’s some debate as to why this is, a recent statistical model suggests that all stars initially form as binaries, then drift apart over a million years. Even our dear Sun is thought to have a long-lost twin out there somewhere in the galaxy. Developing equipment powerful enough to capture detailed views of distant stars also remains a challenge. Stars typically evolve over millennia, so observing them in real-time isn’t very compatible with our relatively short lives.

What we know about star formation has been pieced together using data from instruments like radio telescopes, gamma-ray telescopes, and space-based telescopes like Hubble. But our knowledge of the early lives of stars remains limited, which is why this new observation is so exciting. Located roughly 700 light-years away in the Ophiuchus constellation, within a pipe-shaped dust lane called the Pipe Nebula, lies the binary [BHB2007] 11. Astronomers had already seen a rough outline of the two protostars and their surrounding structures, but this image offers an unprecedented look into the detailed network of gas and dust filaments circling them.



How scientists witnessed the birth of two stars

By leveraging the seeing power of the ALMA radio telescope, an international team of researchers was able to observe two circumstellar disks in the binary system, and a massive surrounding disk totaling about 80 Jupiter masses. Most strikingly, the new data revealed that the developing stars shed their mass from the bigger disk, or the circumbinary disk, in a two-level process.

The first part happens when mass is transferred from the shared disk to the individual circumstellar disks in swirling loops, which is what these new images show. Researchers also found that the smaller but brighter circumstellar disk— the one in the lower part of the image—accretes more material. In the second stage, the two stars accrete mass as a single unit. Since these feeding filaments connect the stars to their birth disk, this new knowledge provides important constraints for existing models of how stars form.



