Search This Blog

Wednesday, November 18, 2009

Close-Up Movie Shows Hidden Details in the Birth of Super-Suns





ScienceDaily (Nov. 16, 2009) — The constellation of Orion is a hotbed of massive star formation, most prominently in the Great Nebula that sits in Orion's sword. The glowing gas of the Nebula is powered by a group of young massive stars, but behind it is a cluster of younger stars and clumps of gas. Still gathering together under gravity's pull, these gas clumps will eventually ignite into stars.

The youthful cluster cannot be seen with traditional telescopes because of the surrounding gas and dust, but a new high-resolution time-lapse movie reveals the process of massive star formation with radio images a thousand times sharper and more detailed than any previously obtained. The movie shows that massive stars form like their smaller siblings, with disk accretion and magnetic fields playing crucial roles.
The way that massive stars form remains mysterious, in part, because massive stars are rare and tend to spend their youth enshrouded by dust and gas hiding them from view.
"We know how these stars die, but not how they are born," said Lincoln Greenhill, a principal investigator of the study and part of a team comprising scientists from the Harvard-Smithsonian Center for Astrophysics (CfA) and the National Radio Astronomy Observatory (NRAO).
Unlike Hubble and other visible-light telescopes, radio telescopes can penetrate dusty veils around stars. The research astronomers studied a massive young protostar called Source I (pronounced "eye") at radio wavelengths, using the National Science Foundation's Very Long Baseline Array (VLBA) as a powerful "zoom lens."

The VLBA yielded even sharper images than the famous Hubble photos of "proplyds," or protoplanetary disks in Orion. The team observed Source I at monthly intervals over two years and then assembled the individual images into a time-lapse movie.
The VLBA detected thousands of silicon monoxide gas clouds called masers -- naturally occurring laser-like beacons often associated with star formation. Some masers were as close to the protostar as Jupiter is to our Sun, which is also a record. Many of the masers existed long enough for their motions to be tracked across the sky and along our line of sight, yielding their 3-d motions through space.

"In astronomy, it's rare to see changes over the course of a human lifetime. With this new movie, we can see changes over just a few months as gas clumps swarm around this young protostar," added Smithsonian astronomer and co-author Ciriaco Goddi.


The resulting movie reveals signs of a rotating accretion disk, where gas is swirling closer and closer to the protostar at the center. It also shows material flowing outward perpendicular to the disk in two large V's -- actually the edges of cone-shaped streams of gas. Such outflows foster star formation by carrying angular momentum away from the system.
Intriguingly, the outflow streams appear to curve as they leave the disk. "The bending path of these masers provides key evidence that magnetic fields may be influencing gas motions very close to the protostar," pointed out Claire Chandler of NRAO, a co-principal investigator of the study.

Source:http://www.sciencedaily.com/releases/2009/11/091116131826.htm

Source of image of the Great Nebula in Orion:http://www.freewebs.com/jezstar/imagesfromspace.htm
Credit & Copyright: Jon Christensen

No comments:

Visit GM Alexandra Kosteniuk's Women's Chess Blog:Please click on the image below:

Visit GM Alexandra Kosteniuk's Women's Chess Blog:Please click on the image below:
Chess needs more women and girl participants and administrators!

Thoughts worth thinking about

"Our subconscious minds have no sense of humor, play no jokes and cannot tell the difference between reality and an imagined thought or image. What we continually think about eventually will manifest in our lives."-Sidney Madwed



Laws alone can not secure freedom of expression; in order that every woman and man present their views without penalty, there must be spirit of tolerance in the entire population.- Albert Einstein Too often we underestimate the power of a touch, a smile, a kind word, a listening ear, an honest compliment, or the smallest act of caring, all of which have the potential to turn a life around. - Leo Buscaglia



A person's true wealth is the good he or she does in the world. - Mohammed



Our task must be to free ourselves... by widening our circle of compassion to embrace all living creatures and the whole of nature and its beauty. -Albert Einstein



The best way to find yourself, is to lose yourself in the service of others. - Ghandi



The unselfish effort to bring cheer to others will be the beginning of a happier life for ourselves. - Helen Keller



Aim for success, not perfection. Never give up your right to be wrong, because then you will lose the ability to learn new things and move forward with your life. Remember that fear always lurks behind perfectionism. Confronting your fears and allowing yourself the right to be human can, paradoxically, make yourself a happier and more productive person. - Dr. David M. Burns



Life is as dear to a mute creature as it is to man. Just as one wants happiness and fears pain, just as one wants to live and not die, so do other creatures. -His Holiness The Dalai Lama



Mankind's true moral test, its fundamental test (which lies deeply buried from view), consists of its attitude towards those who are at its mercy: animals. And in this respect mankind has suffered a fundamental debacle, a debacle so fundamental that all others stem from it. -



Milan Kundera, The Unbearable Lightness of Being



The worst sin towards our fellow creatures is not to hate them, but to be indifferent to them. That's the essence of inhumanity. -George Bernard Shaw

Ego's trick is to make us lose sight of our interdependence. That kind of ego-thought gives us a perfect justification to look out only for ourselves. But that is far from the truth. In reality we all depend on each other and we have to help each other. The husband has to help his wife, the wife has to help the husband, the mother has to help her children, and the children are supposed to help the parents too, whether they want to or not.-Gehlek Rinpoche Source: "The Best Buddhist Writing 2005 pg. 165

The hostile attitude of conquering nature ignores the basic interdependence of all things and events---that the world beyond the skin is actually an extension of our own bodies---and will end in destroying the very environment from which we emerge and upon which our whole life depends.