PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

New studies give strong boost to binary-star formation theory

VLA observations support 1 competing explanation for how double stars are formed

2013-12-31
(Press-News.org) Contact information: Dave Finley
dfinley@nrao.edu
575-835-7302
National Radio Astronomy Observatory
New studies give strong boost to binary-star formation theory VLA observations support 1 competing explanation for how double stars are formed Using the new capabilities of the upgraded Karl G. Jansky Very Large Array (VLA), scientists have discovered previously-unseen binary companions to a pair of very young protostars. The discovery gives strong support for one of the competing explanations for how double-star systems form.

Astronomers know that about half of all Sun-like stars are members of double or multiple-star systems, but have debated over how such systems are formed.

"The only way to resolve the debate is to observe very young stellar systems and catch them in the act of formation," said John Tobin, of the National Radio Astronomy Observatory (NRAO). "That's what we've done with the stars we observed, and we got valuable new clues from them," he added.

Their new clues support the idea that double-star systems form when a disk of gas and dust whirling around one young star fragments, forming another new star in orbit with the first. Young stars that still are gathering matter from their surroundings form such disks, along with jet-like outflows rapidly propelling material in narrow beams perpendicular to the disk.

When Tobin and an international team of astronomers studied gas-enshrouded young stars roughly 1,000 light-years from Earth, they found that two had previously-unseen companions in the plane where their disks would be expected, perpendicular to the direction of the outflows from the systems. One of the systems also clearly had a disk surrounding both young stars.

"This fits the theoretical model of companions forming from fragmentation in the disk," Tobin said. "This configuration would not be required by alternative explanations," he added.

The new observations add to a growing body of evidence supporting the disk-fragmentation idea. In 2006, a different VLA observing team found an orbiting pair of young stars, each of which was surrounded by a disk of material. The two disks, they found, were aligned with each other in the same plane. Last year, Tobin and his colleagues found a large circumstellar disk forming around a protostar in the initial phases of star formation. This showed that disks are present early in the star formation process, a necessity for binary pairs to form through disk fragmentation.

"Our new findings, combined with the earlier data, make disk fragmentation the strongest explanation for how close multiple star systems are formed," said Leslie Looney of NRAO and the University of Illinois.

"The increased sensitivity of the VLA, produced by a decade-long upgrade project completed in 2012, made the new discovery possible," Claire Chandler of NRAO said.

The new capability was particularly valuable at the VLA's highest frequency band, from 40-50 GHz, where dust in the disks surrounding young stars emits radio waves. The astronomers observed the young stars during 2012 with the VLA and with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) in California.

Tobin, Chandler, and Looney were part of a research team of astronomers from the U.S., Mexico, and the Netherlands. The scientists published their findings in the Astrophysical Journal.

### The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.


ELSE PRESS RELEASES FROM THIS DATE:

Final recommendations on lung cancer screening

2013-12-31
Final recommendations on lung cancer screening Embargoed news from Annals of Intenral Medicine Final word: Task Force says screen high-risk populations for lung cancer High-risk adults between the ages of 55 and 80 should receive annual lung cancer screening ...

Climate change spurs tropical mangroves to expand in the north

2013-12-31
Climate change spurs tropical mangroves to expand in the north As mangrove trees lose ground to deforestation and urban sprawl, one development seems to be giving them a boost: climate change. Fewer winter cold snaps have enabled them to conquer new territory around their northern ...

Mangroves expand north as Florida freezes decline

2013-12-31
Mangroves expand north as Florida freezes decline Mangrove forests have been expanding northward along the Atlantic coast of Florida for the last few decades not because of a general warming trend, but likely because cold snaps there are becoming a thing of the ...

With few hard frosts, tropical mangroves push north

2013-12-31
With few hard frosts, tropical mangroves push north N Florida coast transformed by extreme weather change, not overall warming COLLEGE PARK, MD – Cold-sensitive mangrove forests have expanded dramatically along Florida's Atlantic Coast as the frequency of killing frosts ...

Minority physicians care for a majority of underserved patients in the US

2013-12-31
Minority physicians care for a majority of underserved patients in the US Minority physicians also play a large role in the care of patients with poorer health, according to a new study in JAMA Internal Medicine CAMBRIDGE, Mass. – Black, Hispanic and Asian ...

Conversations on sex lacking between doctors and teens

2013-12-31
Conversations on sex lacking between doctors and teens DURHAM, N.C. – Doctors are missing a prime opportunity to share information about sex with their teenage patients by failing to broach the subject during checkups, according to researchers ...

High good and low bad cholesterol levels are healthy for the brain, too

2013-12-31
High good and low bad cholesterol levels are healthy for the brain, too (SACRAMENTO, Calif.) -- High levels of "good" cholesterol and low levels of "bad" cholesterol are correlated with lower levels of the amyloid plaque deposition ...

Field trial with lignin modified poplars shows potential for bio-based economy

2013-12-31
Field trial with lignin modified poplars shows potential for bio-based economy But work still needs to be done The results of a field trial with genetically modified poplar trees in Zwijnaarde, Belgium, shows that the wood of lignin ...

Most clinical studies on vitamins flawed by poor methodology

2013-12-31
Most clinical studies on vitamins flawed by poor methodology CORVALLIS, Ore. – Most large, clinical trials of vitamin supplements, including some that have concluded they are of no value or even harmful, have a flawed methodology that renders them largely ...

Molecular evolution of genetic sex-determination switch in honeybees

2013-12-31
Molecular evolution of genetic sex-determination switch in honeybees 5 amino acid differences separate males from females It's taken nearly 200 years, but scientists in Arizona and Europe have teased out how the molecular switch for sex gradually ...

LAST 30 PRESS RELEASES:

Less intensive works best for agricultural soil

Arctic rivers project receives “national champion” designation from frontiers foundation

Computational biology paves the way for new ALS tests

Study offers new hope for babies born with opioid withdrawal syndrome

UT, Volkswagen Group of America celebrate research partnership

New Medicare program could dramatically improve affordability for cancer drugs – if patients enroll

Are ‘zombie’ skin cells harmful or helpful? The answer may be in their shapes

University of Cincinnati Cancer Center presents research at AACR 2025

Head and neck, breast, lung and survivorship studies headline Dana-Farber research at AACR Annual Meeting 2025

AACR: Researchers share promising results from MD Anderson clinical trials

New research explains why our waistlines expand in middle age

Advancements in muon detection: Taishan Antineutrino Observatory's innovative top veto tracker

Chips off the old block

Microvascular decompression combined with nerve combing for atypical trigeminal neuralgia

Cutting the complexity from digital carpentry

Lung immune cell type “quietly” controls inflammation in COVID-19

Fiscal impact of expanded Medicare coverage for GLP-1 receptor agonists to treat obesity

State and sociodemographic trends in US cigarette smoking with future projections

Young adults drive historic decline in smoking

NFCR congratulates Dr. Robert C. Bast, Jr. on receiving the AACR-Daniel D. Von Hoff Award for Outstanding Contributions to Education and Training in Cancer Research

Chimpanzee stem cells offer new insights into early embryonic development

This injected protein-like polymer helps tissues heal after a heart attack

FlexTech inaugural issue launches, pioneering interdisciplinary innovation in flexible technology

In Down syndrome mice, 40Hz light and sound improve cognition, neurogenesis, connectivity

Methyl eugenol: potential to inhibit oxidative stress, address related diseases, and its toxicological effects

A vascularized multilayer chip reveals shear stress-induced angiogenesis in diverse fluid conditions

AI helps unravel a cause of Alzheimer's disease and identify a therapeutic candidate

Coalition of Autism Scientists critiques US Department of Health and Human Services Autism Research Initiative

Structure dictates effectiveness, safety in nanomedicine

Mission accomplished for the “T2T” Hong Kong Bauhinia Genome Project

[Press-News.org] New studies give strong boost to binary-star formation theory
VLA observations support 1 competing explanation for how double stars are formed