. 24/7 Space News .
How to Spin a Disk Around Young Protostars
by Staff Writers
Garching, Germany (SPX) Sep 09, 2019

file illustration only

The main steps of star and planet formation are well understood: a dense, interstellar cloud will collapse under its own gravity; a central core forms as well as a protostellar disk due to the conservation of angular momentum; finally, after about 100,000 years or so, the star will become dense enough to ignite nuclear fusion at its centre and so will start to shine, while in the disk, planets will form.

But there are still many open questions about the details of this process, e.g., what is the role of angular momentum in disk formation or how does the circum-stellar disk gather most of its mass?

An international team of scientists led by the Max Planck Institute for Extraterrestrial Physics (MPE) has now observed three of the youngest protostellar sources in the Perseus molecular cloud. These sources are close to edge-on in the plane of the sky, allowing a study of the velocity distribution of the dense cloud.

"This is the first time that we were able to analyze the gas kinematics around three circum-stellar disks in early stages of their formation," states Jaime Pineda, who led the study at MPE. "All systems can be fit with the same model, which gave us the first hint that the dense clouds do not rotate as a solid body."

A solid body rotation is the simplest assumption, which describes the gas in the dense cloud with a fixed angular speed at any given radius. The model best describing all three systems is in between those expected for solid body rotation and pure turbulence.

Furthermore, when comparing these observations to previous numerical models, it is clear that magnetic fields play a role in the formation of these disks: "If a magnetic field is included it makes sure that the collapse is not too fast and the gas rotation matches the observed one," explains Pineda. "Our latest observations give us an upper limit on the disk sizes, which are in great agreement with previous studies."

In particular, the specific angular momentum of the in-falling material is directly related to the possible maximum Keplerian radius of the protostellar disk. Assuming a stellar mass of about 5% of the mass of our Sun, the scientists estimate that the upper limit of the Keplerian disk is about 60 astronomical units (AU), or about the double the size of our planetary system, in agreement with previous estimates. This suggests that big disks (greater than 80 AU) cannot be formed early in the life of a star, and therefore affects the starting point for planet forming scenarios.

The next step for the astronomers will be to observe such systems at various stages in their evolution and in different environments to check if these influence the specific angular momentum profile. These findings can then be incorporated in or compared with numerical simulations to better understand the co-evolution of the dense core forming a star and the circumstellar disk forming planets.

Research Report: "The Specific Angular Momentum Radial Profile in Dense Cores: Improved Initial Conditions for Disk Formation"

Related Links
Max Planck Institute For Extraterrestrial Physics
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only
SpaceDaily Contributor
$5 Billed Once

credit card or paypal

Potassium Detected in an Exoplanet Atmosphere
Potsdam, Germany (SPX) Sep 05, 2019
A team of astronomers led by AIP PhD student Engin Keles detected the chemical element potassium in the atmosphere of an exoplanet, for the first time with overwhelming significance and applying high-resolution spectroscopy. The Potsdam Echelle Polarimetric and Spectroscopic Instrument at the Large Binocular Telescope in Arizona was used to study the atmosphere on the Jupiter-like exoplanet HD 189733b. Ever since the earliest theoretical predictions 20 years ago, the chemical elements potassium an ... read more

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Company Claims Orbital Hotel to Host 400 Space Tourists Will Be Operational By 2025

Malaysia Interested in Having Access to Russian Space Tech, Prime Minister Says

Europe Unlikely to Abandon Soyuz Once US Revives Space Shuttles - German Space Center

UAE Wants to Train More Astronauts for Arab World - Emirati Official

Russia Launches Rokot Space Rocket to Orbit Military Satellite

Vega Flight VV15: Findings of the Independent Inquiry Commission's investigations

Trump says US 'not involved' in Iranian rocket failure

Firefly Aerospace pushes back first launch to 2020

NASA Research Gives New Insight into How Much Atmosphere Mars Lost

NASA engineers attach Mars Helicopter to Mars 2020 rover

ESA Chief says discussed ExoMars 2020 launch with Roscosmos

NASA Invites Students to Name Next Mars Rover

China's KZ-1A rocket launches two satellites

China's newly launched communication satellite suffers abnormality

China launches first private rocket capable of carrying satellites

Chinese scientists say goodbye to Tiangong-2

Private Chinese firms tapping international space market

Iridium and Thales Expand Partnership to Deliver Aircraft Connectivity Services

ESA re-routes satellite to avoid SpaceX collision risk

Cutting-edge Chinese satellite malfunctions after launch

Seeking moments of disorder

China's Tianhe-2 Supercomputer to Crunch Space Data From New Radio Telescope

Defrosting surfaces in seconds

ESA spacecraft dodges large constellation

Planetary collisions can drop the internal pressures in planets

Potassium Detected in an Exoplanet Atmosphere

Deep-sea sediments reveal solar system chaos: An advance in dating geologic archives

Exoplanets Can't Hide Their Secrets from Innovative New Instrument

Storms on Jupiter are disturbing the planet's colorful belts

ALMA shows what's inside Jupiter's storms

Young Jupiter was smacked head-on by massive newborn planet

Mission to Jupiter's icy moon confirmed

The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.