Planetary system formation is a process that involves astounding and complex forces. Humans have only just started trying to understand what goes on in this extraordinarily important phase of the development of new worlds. As such, we are continuing to make new discoveries and come up with better models that better fit the observations that our instruments are able to collect.
The most recent of those improved models was announced by a research team at the University of Warwick. A paper in Astrophysical Journal Letters explores possible reasons for why there is a lack of spiral structures in newly formed protoplanetary discs. Their answer is a simple one: massive planets that form on the outside of the disc might be disrupting the spiral formation.
Over the last few years, astronomers have observed distant solar systems in their early stages of growth. ALMA (Atacama Large Millimeter/submillimeter Array) has captured images of young stars and their disks of material. And in those disks, they’ve spotted the tell-tale gaps that signal the presence of growing young planets.
As they ramped up their efforts, astronomers were eventually able to spot the young planets themselves. All those observations helped confirm our understanding of how young solar systems form.
But more recent research adds another level of detail to the nebular hypothesis, which guides our understanding of solar system formation.
This week we are joined by Dr. Jane Huang and Dr. Jonathan Willams from the Center for Astrophysics, Harvard & Smithsonian (CfA). Dr. Huang, Dr. Williams, and their team recently discovered some surprising information about the size and shape of some protoplanetary disks.
Protoplanetary disks – where young stars are forming their families of planets – usually form concentric rings of gaps. But astronomers have recently spotted a surprising situation: an adolescent star surrounded by galaxy-like spiral arms.
Astronomers like to observe young planets forming in circumstellar debris disks, the rotating rings of material around young stars. But when they measure the amount of material in those disks, they don’t contain enough material to form large planets. That discrepancy has puzzled astronomers.
The answer might come down to timing.
A new study suggests that planets form much quicker than astronomers think.
Astronomers like observing distant young stars as they form. Stars are born out of a molecular cloud, and once enough of the matter in that cloud clumps together, fusion ignites and a star begins its life. The leftover material from the formation of the star is called a circumstellar disk.
As the material in the circumstellar disk swirls around the now-rotating star, it clumps up into individual planets. As planets form in it, they leave gaps in that disk. Or so we think.
According to the most widely accepted theory of planet formation (the Nebular Hypothesis), the Solar System began roughly 4.6 billion years ago from a massive cloud of dust and gas (aka. a nebula). After the cloud experienced gravitational collapse at the center, forming the Sun, the remaining gas and dust fell into a disk that orbited it. The planets gradually accreted from this disk over time, creating the system we know today.
However, until now, scientists have wondered how dust could come together in microgravity to form everything from stars and planets to asteroids. However, a new study by a team of German researchers (and co-authored by Rutgers University) found that matter in microgravity spontaneously develops strong electrical charges and stick together. These findings could resolve the long mystery of how planets formed.
We’ve all heard this one: when you drink a glass of water, that water has already been through a bunch of other people’s digestive tracts. Maybe Attila the Hun’s or Vlad the Impaler’s; maybe even a Tyrannosaurus Rex’s.
Well, the same thing is true of stars and matter. All the matter we see around us here on Earth, even our own bodies, has gone through at least one cycle of stellar birth and death, maybe more. But which type of star?
That’s what a team of researchers at ETH Zurich (Ecole polytechnique federale de Zurich) wanted to know.
Perhaps the greatest discovery to come from the “Golden Age of General Relativity” (ca. 1960 to 1975) was the realization that a supermassive black hole (SMBH) exists at the center of our galaxy. In time, scientists came to realize that similarly massive black holes were responsible for the extreme amounts of energy emanating from the active galactic nuclei (AGNs) of distant quasars.
Given their sheer size, mass, and energetic nature, scientists have known for some time that some pretty awesome things take place beyond the event horizon of an SMBH. But according to a recent study by a team of Japanese researchers, it is possible that SMBHs can actually form a system of planets! In fact, the research team concluded that SMBHs can form planetary systems that would put our Solar System to shame!
370 light years away from us, a solar system is making baby planets. The star at the center of it all is young, only about 6 million years old. And its babies are two enormous planets, likely both gas giants, nursing on gaseous matter from the star’s circumsolar disk.