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

ALMA sheds light on planet-forming gas streams

Tantalizing signs of flows feeding gas-guzzling giant planets

2013-01-03
(Press-News.org) Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope have seen a key stage in the birth of giant planets for the first time. Vast streams of gas are flowing across a gap in the disc of material around a young star. These are the first direct observations of such streams, which are expected to be created by giant planets guzzling gas as they grow. The result is published on 2 January 2013 in the journal Nature.

The international team of astronomers studied the young star HD 142527, over 450 light-years from Earth, which is surrounded by a disc of gas and cosmic dust — the remains of the cloud from which the star formed. The dusty disc is divided into an inner and an outer part by a gap, which is thought to have been carved by newly forming gas giant planets clearing out their orbits as they circle the star. The inner disc reaches from the star out to the equivalent of the orbit of Saturn in the Solar System, while the outer disc begins about 14 times further out. The outer disc does not surround the star uniformly; instead, it has a horseshoe shape, probably caused by the gravitational effect of the orbiting giant planets.

According to theory, the giant planets grow by capturing gas from the outer disc, in streams that form bridges across the gap in the disc.

"Astronomers have been predicting that these streams must exist, but this is the first time we've been able to see them directly," says Simon Casassus (Universidad de Chile, Chile), who led the new study. "Thanks to the new ALMA telescope, we've been able to get direct observations to illuminate current theories of how planets are formed!"

Casassus and his team used ALMA to look at the gas and cosmic dust around the star, seeing finer details, and closer to the star, than could be seen with previous such telescopes. ALMA's observations, at submillimetre wavelengths, are also impervious to the glare from the star that affects infrared or visible-light telescopes. The gap in the dusty disc was already known, but they also discovered diffuse gas remaining in the gap, and two denser streams of gas flowing from the outer disc, across the gap, to the inner disc.

"We think that there is a giant planet hidden within, and causing, each of these streams. The planets grow by capturing some of the gas from the outer disc, but they are really messy eaters: the rest of it overshoots and feeds into the inner disc around the star" says Sebastián Pérez, a member of the team, who is also at Universidad de Chile.

The observations answer another question about the disc around HD 142527. As the central star is still forming, by capturing material from the inner disc, the inner disc would have already been devoured, if it was not somehow topped up. The team found that the rate at which leftover gas streams onto the inner disc is just right to keep the inner disc replenished, and to feed the growing star.

Another first is the detection of the diffuse gas in the gap. "Astronomers have been looking for this gas for a long time, but so far we only had indirect evidence for it. Now, with ALMA, we can see it directly," explains Gerrit van der Plas, another team member at Universidad de Chile.

This residual gas is more evidence that the streams are caused by giant planets, rather than even larger objects such as a companion star. "A second star would have cleared out the gap more, leaving no residual gas. By studying the amount of gas left, we may be able to pin down the masses of the objects doing the clearing." adds Pérez.

What about the planets themselves? Casassus explains that, although the team did not detect them directly, he is not surprised. "We searched for the planets themselves with state-of-the-art infrared instruments on other telescopes. However, we expect that these forming planets are still deeply embedded in the streams of gas, which are almost opaque. Therefore, there may be little chance of spotting the planets directly."

Nevertheless, the astronomers aim to find out more about the suspected planets by studying the gas streams as well as the diffuse gas. The ALMA telescope is still under construction, and has not yet reached its full capabilities. When it is complete, its vision will be even sharper, and new observations of the streams may allow the team to determine properties of the planets, including their masses. ### END


ELSE PRESS RELEASES FROM THIS DATE:

Nature: Political action the biggest swing factor in meeting climate targets

2013-01-03
The new study, published today in the journal Nature, examined the probability of keeping average global temperatures from rising more than 2°C above preindustrial levels under varying levels of climate policy stringency, and thus mitigation costs. In addition, the study for the first time quantified and ranked the uncertainties associated with efforts to mitigate climate change, including questions about the climate itself, uncertainties related to future technologies and energy demand, and political uncertainties as to when action will be taken. The climate system itself ...

Our galaxy's 'geysers' are towers of power

Our galaxys geysers are towers of power
2013-01-03
VIDEO: This is Ettore Carretti talking about how the telescope makes maps of the sky. Click here for more information. "Monster" outflows of charged particles from the centre of our Galaxy, stretching more than halfway across the sky, have been detected and mapped with CSIRO's 64-m Parkes radio telescope. Corresponding to the "Fermi Bubbles" found in 2010, the outflows were detected by astronomers from Australia, the USA, Italy and The Netherlands. The finding is reported ...

Study refutes accepted model of memory formation

2013-01-03
A study by Johns Hopkins researchers has shown that a widely accepted model of long-term memory formation — that it hinges on a single enzyme in the brain — is flawed. The new study, published in the Jan. 2 issue of Nature, found that mice lacking the enzyme that purportedly builds memory were in fact still able to form long-term memories as well as normal mice could. "The prevailing theory is that when you learn something, you strengthen connections between your brain cells called synapses," explains Richard Huganir, Ph.D., a professor and director of the Johns Hopkins ...

ALMA shows how young star and planets grow simultaneously

2013-01-03
Astronomers have used the ALMA telescope to get their first glimpse of a fascinating stage of star formation in which planets forming around a young star are helping the star itself continue to grow, resolving a longstanding mystery. The young system, about 450 light-years from Earth, is revealing its complex gravitational dance to the ever-sharpening vision of the Atacama Large Millimeter/submillimeter Array (ALMA), scheduled for completion this year. As young stars gather material from their surrounding clouds of gas and dust, the incoming material forms a flat, spinning ...

Galactic geysers fuelled by star stuff

2013-01-03
Enormous outflows of charged particles from the centre of our Galaxy, stretching more than halfway across the sky and moving at supersonic speeds, have been detected and mapped with CSIRO's 64-m Parkes radio telescope. Corresponding to the "Fermi Bubbles" found in 2010, the recent observations of the phenomenon were made by a team of astronomers from Australia, the USA, Italy and The Netherlands, with the findings reported in today's issue of Nature. "There is an incredible amount of energy in the outflows," said co-author Professor Lister-Staveley-Smith from The University ...

The laws of global warming

2013-01-03
With policymakers and political leaders increasingly unable to combat global climate change, more scientists are considering the use of manual manipulation of the environment to slow warming's damage to the planet. But a University of Iowa law professor believes the legal ramifications of this kind of geo-engineering need to be thought through in advance and a global governance structure put in place soon to oversee these efforts. "Geo-engineering is a global concern that will have climate and weather impacts in all countries, and it is virtually inevitable that some ...

Communication is key to medication adherence

2013-01-03
Even the best medicines in the world can be rendered ineffective if they are not taken as prescribed. The problem known as medication "non-adherence" is a major health issue in the United States, contributing to worse outcomes for people who have diabetes and other chronic diseases. Now a study led by researchers at the University of California, San Francisco (UCSF), San Francisco General Hospital and Trauma Center (SFGH) and the Kaiser Permanente Division of Research has identified a significant factor that contributes to poor drug adherence – ineffective communication. Described ...

Bisexual men on the 'down low' run risk for poor mental health

2013-01-03
January 2, 2013 -- Bisexual men are less likely to disclose and more likely to conceal their sexual orientation than gay men. In the first study to look at the mental health of this population, researchers at Columbia University's Mailman School of Public Health found that greater concealment of homosexual behavior was associated with more symptoms of depression and anxiety. The study published in the American Psychological Association's Journal of Consulting and Clinical Psychology, examined bisexual men "on the down low," a subgroup of bisexual men who live predominantly ...

Common data determinants of recurrent cancer are broken, mislead researchers

2013-01-03
In order to study the effectiveness or cost effectiveness of treatments for recurrent cancer, you first have to discover the patients in medical databases who have recurrent cancer. Generally studies do this with billing or treatment codes – certain codes should identify who does and does not have recurrent cancer. A recent study published in the journal Medical Care shows that the commonly used data determinants of recurrent cancer may be misidentifying patients and potentially leading researchers astray. "For example, a study might look in a database for all patients ...

Previous studies on toxic effects of BPA couldn't be reproduced

2013-01-03
Following a three-year study using more than 2,800 mice, a University of Missouri researcher was not able to replicate a series of previous studies by another research group investigating the controversial chemical BPA. The MU study is not claiming that BPA is safe, but that the previous series of studies are not reproducible. The MU study, published in the Proceedings of the National Academy of Sciences, also investigated an estrogenic compound found in plants, genistein, in the same three-year study. "Our findings don't say anything about the positive or negative effects ...

LAST 30 PRESS RELEASES:

Toxic metals linked to impaired growth in infants in Guatemala

Being consistently physically active in adulthood linked to 30–40% lower risk of death

Nerve pain drug gabapentin linked to increased dementia, cognitive impairment risks

Children’s social care involvement common to nearly third of UK mums who died during perinatal period

‘Support, not judgement’: Study explores links between children’s social care involvement and maternal deaths

Ethnic minority and poorer children more likely to die in intensive care

Major progress in fertility preservation after treatment for cancer of the lymphatic system

Fewer complications after additional ultrasound in pregnant women who feel less fetal movement

Environmental impact of common pesticides seriously underestimated

The Milky Way could be teeming with more satellite galaxies than previously thought

New study reveals surprising reproductive secrets of a cricket-hunting parasitoid fly

Media Tip Sheet: Symposia at ESA2025

NSF CAREER Award will power UVA engineer’s research to improve drug purification

Tiny parasitoid flies show how early-life competition shapes adult success

New coating for glass promises energy-saving windows

Green spaces boost children’s cognitive skills and strengthen family well-being

Ancient trees dying faster than expected in Eastern Oregon

Study findings help hone precision of proven CVD risk tool

Most patients with advanced melanoma who received pre-surgical immunotherapy remain alive and disease free four years later

Introducing BioEmu: A generative AI Model that enables high-speed and accurate prediction of protein structural ensembles

Replacing mutated microglia with healthy microglia halts progression of genetic neurological disease in mice and humans

New research shows how tropical plants manage rival insect tenants by giving them separate ‘flats’

Condo-style living helps keep the peace inside these ant plants

Climate change action could dramatically limit rising UK heatwave deaths

Annual heat-related deaths projected to increase significantly due to climate and population change

Researchers discover new way cells protect themselves from damage

Rivers choose their path based on erosion — a discovery that could transform flood planning and restoration

New discovery reveals dopamine operates with surgical precision, not as a broad signal

New AI tool gives a helping hand to x ray diagnosis

New Leicester study reveals hidden heart risks in women with Type 2 Diabetes

[Press-News.org] ALMA sheds light on planet-forming gas streams
Tantalizing signs of flows feeding gas-guzzling giant planets