When a young solar system gets going it’s little more than a young star and a rotating disk of debris. Accepted thinking says that the swirling debris is swept up in planet formation. But a new study says that much of the matter in the disk could face a different fate.
It may not have the honour of becoming part of a nice stable planet, orbiting placidly and reliably around its host star. Instead, it’s simply discarded. It’s ejected out of the young, still-forming solar system to spend its existence as interstellar objects or as rogue planets.
Planet formation is notoriously difficult to study. Not only does the process take millions of years, making it impossible to observe in real time, there are myriad factors that play into it, making it difficult to distinguish cause and effect. What we do know is that planets form from features known as protoplanetary disks, which are made up of gas and dust surrounding young stars. And now a team using ALMA have found a star system that has a protoplanetary disk and enough variability to help them nail down some details of how exactly the process of planet formation works.
Planets form from the accumulation of countless grains of dust swirling around young stars. New computer simulations have found that planets begin forming earlier than previously thought, when a planet’s star hasn’t even finished forming yet.
Many planetary systems may get snuffed out before they even get a chance to form, according to new research. The culprit: nearby stars, capable of evaporating entire protoplanetary disks just when they begin to form.
Astronomers have been watching planetary systems form around sun-like stars for decades. And now, new observations with the ALMA telescope reveal the same process playing out around the smallest, but most common, stars in galaxy.
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.