Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mapping Orion’s winds

11.01.2006


For the past few months, Bob O’Dell has been mapping the winds blowing in the Orion Nebula, the closest stellar nursery similar to the one in which the sun was born.

New data from the Hubble Orion Heritage Program, a major observational effort by the Hubble Space Telescope in 2004 and 2005, have given the Vanderbilt astronomer the information he needs to measure the stellar winds with unprecedented detail, and he reported his early results on Jan. 11 at the annual meeting of the American Astronomical Society in Washington D.C.

"Determining how stellar winds interact with the ambient material in stellar nurseries like Orion is a critical factor in understanding the process of star creation," says O’Dell, distinguished research professor of astrophysics and an international authority on Orion.



All stars, including the Sun, give off a stream of particles as they burn. In young, hot stars like those that form the "Trapezium" at the heart of Orion this stream of particles is millions of times more dense and energetic than the solar wind. Newborn stars, which are still shrouded in thick veils of dust and gas, often eject gas and dust from their polar regions in narrow jets, rather than broadcasting them outward in all directions. When these stellar winds impact floating clouds of dust and gas, they produce shock waves that erode and shape the clouds in a fashion similar to the way in which terrestrial winds sculpt sand dunes. When they are strong enough, such shock waves also can compress the free-floating clouds of dust and gas, triggering the formation of new stars.

O’Dell is using these shock waves as celestial "wind socks" to plot the direction of these winds in different parts of the nebula. By back-tracking older, more distant shock waves to their likely points of origin, the astronomer can also get an idea of how long major currents have been flowing.

"When you look closely enough, you see that the nebula is filled with hundreds of visible shock waves," the astronomer says.

In his analysis, O’Dell has identified three different types of shock waves:

  • Bow-shocks are stationary shock waves that are formed by the collision of two steady winds and are excellent indicators of wind direction. They are present near the hottest stars in the center of the nebula where they show winds flowing outward at velocities of thousands of kilometers per second. They are also present in the outer nebula where they are produced by low velocity stellar winds of tens of kilometers per second.
  • Jet-driven shocks are produced when narrow streams of gas and particles traveling at hundreds of kilometers per second pass through gas that is relatively stationary. There are many shockwaves of this type in the nebula that are produced by jets of material ejected by newly formed stars.
  • Warped shocks are jet-driven shocks located in areas where the ambient gas is not stationary but is moving in a cross current. This bends the jets and shocks into bow-like shapes.

Using these markers, the astronomer has mapped the outflow from two of the three regions of star formation in the nebula. Both of these regions, labeled BN-KL and Orion-South, are located behind the glowing region of the nebula where the light from the central stars ionizes the outer layers of the parent molecular cloud. The specific objects that are producing these winds in the two regions are not visible to optical telescopes but they stand out as hot spots in infrared images.

By tracking back the farthest shockwaves produced by these outflows, O’Dell has established that the winds blowing from BN-KL have been doing so for 900 to 1,100 years, while those from Orion-South have been going on for 200 to 1,500 years. These observations were made during 104 orbits of the Hubble and provide the most comprehensive picture ever obtained of the Orion Nebula. The data will be combined with other Hubble and ground-based telescope observations to create a widely available archive for research scientists interested in this region, in addition to acting as a base for a detailed study that should provide new insights into the conditions required for creating stars like the sun.

David F. Salisbury | EurekAlert!
Further information:
http://www.vanderbilt.edu
http://www.exploration.vanderbilt.edu

More articles from Physics and Astronomy:

nachricht UNLV study unlocks clues to how planets form
13.12.2018 | University of Nevada, Las Vegas

nachricht Unprecedented Views of the Birth of Planets
13.12.2018 | Universität Heidelberg

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Magic number colloidal clusters

13.12.2018 | Life Sciences

UNLV study unlocks clues to how planets form

13.12.2018 | Physics and Astronomy

Live from the ocean research vessel Atlantis

13.12.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>