Structures created during cataclysmic collisions between objects left over from planet formation or something unknown?
Space news (July 13, 2015) – collisions indicating possible gravitational effects of unseen orbiting exoplanets or consequences of the star traveling through interstellar space –
Space scientists using the Hubble Space Telescope recently completed a visible-light imaging survey of the debris field systems around 10 young stars between the ages of 10 million to 1 billion years old. Debris fields they studied in order to better understand the early solar system and formation of the planets.
“It’s like looking back in time to see the kinds of destructive events that once routinely happened in our solar system after the planets formed,” said survey leader Glenn Schneider of the University of Arizona’s Steward Observatory.
What did the survey find?
Space scientists studying the evolution of stars and the formation of planets used to think debris fields surrounding young stars should be composed of simple pancake-like structures.
The complexity and diversity in debris fields studied in this recent survey strongly suggest this scenario is a little more involved than theories suggest. Facts indicate the possibility of gravitational effects of unseen exoplanets hidden within the dusty debris, the results of the young star traveling through interstellar space, or something unthought of as the reason for the deviation from theory.
“We find that the systems are not simply flat with uniform surfaces,” Schneider said. “These are actually pretty complicated three-dimensional debris systems, often with embedded smaller structures. Some of the substructures could be signposts of unseen planets.” The astronomers used Hubble’s Space Telescope
Imaging Spectrograph to study 10 previously discovered circumstellar debris systems.
Star HD 181327 Shows Huge Debris Spray
The ring-like debris system surrounding star HD 181327 has irregularities space scientists think could be due to a recent collision between two bodies on the outer part of the system.
“This spray of material is fairly distant from its host star — roughly twice the distance that Pluto is from the sun,” said co-investigator Christopher Stark. “Catastrophically destroying an object that massive at such a large distance is difficult to explain, and it should be very rare. If we are in fact seeing the recent aftermath of a massive collision, the unseen planetary system may be quite chaotic.”
“Another interpretation for the irregularity is that the disk has been mysteriously warped by the star’s passage through interstellar space, directly interacting with the unseen interstellar material. “Either way, the answer is exciting,” Schneider said. “Our team is currently analyzing follow-up observations that will help reveal the true cause of the irregularity.”
As of 07/09/2015 space scientists have verified the existence of 1858 exoplanets, including 468 exosolar systems with multiple planets, and 92 Earth-size terrestrial-type planets. The structure and overall architecture of the systems discovered so far are more diverse than astrophysicists first proposed.
During this time, space scientists have only viewed about two dozen light-scattering, circumstellar debris systems due to their comparative faintness and proximity to their parent stars. Despite the small sample size in exoplanetary debris systems astronomers view a surprising variety of architectures.
“We are now seeing a similar diversity in the architecture of the accompanying debris systems,” Schneider said. “How are the planets affecting the disks, and how are the disks affecting the planets? There is some sort of interdependence between a planet and the accompanying debris that might affect the evolution of these exoplanetary debris systems.”
Space scientists will now use the results obtained through this survey and the overall study of the debris system disks viewed to devise new theories and experiments to determine more about the evolution and growth of young stars in the cosmos.
They’ll also use the data and information gained to begin looking at how our solar system formed and evolved during the past 4.6 billion years. They want to study collisions between objects like HD 181327 and Earth-like planets to give more insight into the birth and evolution of our planet and the Moon during the first moments of the solar system.
You can learn more about and follow NASA’s space mission here.
Learn more about the Hubble Space Telescope here.