I’ve been practicing astronomy for a very long time, and I still think one of the coolest things we can do right now is literally see stars forming, combining from the disks of gas and dust around them.
Even cooler than that, we can see planetary systems forming around it.
But there are still great scales within that frame, and somewhere near the top is the binary star SVS 13. Why? Well, not only is it a young star system still forming during planet formation, it also emits trillions of kilometers long jets of gas at the same time.
And the kicker? It is not just about the formation of planets around each of the two stars separately, It may also form planets orbiting both.
This means that these two stars may form Three distinct planetary systems. I’m not even sure I would have thought that was possible.
SVS 13 lies about a thousand light-years from Earth — relatively close to our 120,000 light-year-wide galaxy — and is part of the massive Perseus Molecular Cloud, a vast, dense, cold cloud of gas and dust. Parts of this cloud collapse to form stars, and in some places the material around it is shining. NGC 1333 is a very luminous example of this, as we see dozens of stars being born.
SVS 13 looks like a single star to visible light telescopes, but careful observations in the radio portion of the spectrum using the Very Large Array (or VLA) show it’s a binary star, with two low-mass stars orbiting each other about 14 billion kilometers, or three times the distance. Between the sun and Neptune. The two components are called VLA 4A, which is about ¼ solar masses, and VLA 4B, which is about 0.6 solar masses.
The stars lie at the base of a small cavity sculpted in gas and dust in NGC 1333, with several points of gas within the cavity emitting light. These are caused by bundles of material emitted from the forming stars such as water from the fire chamber. These are generally called Herbig-Haro objects and those seen near SVS 13 are specifically called HH 7 to 11. So it’s very clear that the two stars are not only young but still in the process of formation.
New notes using VLA [link to paper] I researched the binary system on very small scales and the results were very surprising. VLA is sensitive to radio light emitted by the warm dust and gas surrounding these stars, and astronomers have found clear evidence that each of the two stars has a disk of dust and gas around it, with VLA 4A’s disk about 4 billion kilometers wide and one around 4B about 3 billion. The amount of material around 4A is enough to easily make a thousand Earths (or a few Jupiters) and the disk around 4B, although smaller, could contain twice as much material.
That’s right there very amazing. We know that low-mass stars like these, called red dwarfs, are not only capable of forming planets but tend to form smaller rocky planets like Earth versus large gas giants like Jupiter. The nearby low-mass star TRAPPIST-1 contains seven Earth-sized planets, all clustered closer to the star than Mercury orbiting the Sun. So it seems like a good bet that both stars might get their own planetary system when things settle down.
Interestingly enough, in fact, astronomers have also discovered organic molecules, complex carbon-based molecules, in this material around stars. While this does not indicate the existence of life, these molecules may have been the precursor to life, the basic types of building blocks for life on Earth began. In a few billion years, who knows what that will lead to?
VLA observations also show that the two stars are embedded in a much larger disk 150 billion kilometers wide. The disc is still in the early stages of configuration. Amazingly, very detailed observations of this system have been taken for 30 years, and over that time the stars have moved enough in their orbits around each other to actually see them move. The amount of motion depends on their orbital velocity, which depends on gravity and therefore the mass of the system, which has allowed astronomers to get the combined mass of stars, gas and dust: roughly the same as the mass of the Sun. All this complexity from just material!
But there is more. The total mass of dust and gas only in that larger disk is about 5% that of the Sun, but don’t be fooled; This is a lot of material, enough to make 50 planets. The notes also show a helical disc pattern, which is really interesting; This is sometimes the calling card of an embedded planet whose gravity perturbs the matter around it. However, it is also possible, and probably more likely, that this is the result of material falling from the surrounding gas cloud on the two stars themselves – this has been seen before in the formation of a binary system. As the stars orbit each other, the falling matter can wind up like pretzels.
The present observations are not sufficient to distinguish between the two. It depends on a lot of factors such as the masses of the stars, which are difficult to determine with enough certainty. Future observations may be able to solve this problem.
Since the large disk is still uniting, it may be able to form planets orbiting both stars round planets Think of Tatooine as an example.
This is the possibility that amazes me. Upon completion of their formation within a few million years, these two stars could each have their own planets, and another set of planets orbit far away. three Groups of planets! It wouldn’t be possible for all three to have Earth-like planets, because distant planets would be very cold, like Neptune or Pluto, but still. Even thinking about such a system is very exciting.
I love that all the weird and imaginary planets you read about in science fiction novels as a kid can actually be real, even some that no one ever thought of before. And we can see them taking shape.
Nature really can be smarter than us. It tells amazing stories.