Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Astronomers take revealing peek at star factory

13.01.2005


Observations eventually expected lead to increased understanding of interstellar dust and gas

Using NASA’s orbiting Far Ultraviolet Spectroscopic Explorer, a team of astronomers from The Johns Hopkins University and elsewhere has taken an unprecedented peek beneath the "skirts" of the tunic-clad Orion the Hunter and come away with observations that may lead to enhanced knowledge of how interstellar dust absorbs and scatters ultraviolet starlight. "Understanding interstellar dust is important. After all, this is the stuff out of which, ultimately, planets, stars and even people are made," said team member Richard Conn Henry, a professor in the Henry A. Rowland Department of Physics and Astronomy at Johns Hopkins. Henry presented findings during the American Astronomical Society’s meeting this week in San Diego.

The constellation Orion, named for its resemblance to a powerful, tunic-clad hunter wielding a club and sword, is probably the greatest star factory in our galaxy, with thousands of young, hot, blue stars emerging from its great clouds of gas and dust. Led by Jayant Murthy of the Indian Institute of Astrophysics, the team examined data FUSE recorded near the most active region of current star formation.



What they saw surprised them.

"FUSE detected a spectrum of ultraviolet light in a region where there is no star at all," said Murthy, who spent many years at Johns Hopkins before going to the Indian Institute. "The spectrum is of light reflecting from the dust in a region near a quite bright star, whose spectrum is very similar to that of the reflected light we detected. At first, we thought that particular star was the original source of the light. But a closer look revealed that, despite the similarity, there were differences -- differences striking enough to allow us to conclude that the star in question could not be the source of the light that is scattering from the dust. So where was that light coming from?"

Team members suspect that the light in question emanated from the Trapezium, a cluster of stars located in the heart of the Orion Nebula. So named because the configuration of its stars resembles a geometric quadrilateral with two parallel sides, the Trapezium not only is one of the most famous multiple star systems in the night sky, but is also -- at only about 1 million years old -- the youngest.

"The ultimate aim of this work is to understand exactly in what manner the light gets reflected: What is this interstellar dust from which the stars are born?" asks David Sahnow, a research scientist in the Department of Physics and Astronomy at Johns Hopkins and a member of the investigating team. "To what extent does the dust absorb the light, and to what extent does it scatter it? For that light which is scattered, does it go backward, forward, or sideways?"

Perhaps one of the most interesting aspects of this investigation into interstellar dust is that it happened serendipitously.

"This is a great example of how science works sometimes, how you can stumble across something valuable while looking for something else," said Murthy. "We were actually taking engineering tests at some semi-random places in the sky while FUSE was thermalizing, and we noticed this. Our discovery that FUSE’s high spectral resolution can actually be applied to diffuse radiation has additional ramifications. High spectral resolution is often a key to physical understanding, and our Orion observation shows that we will be able to use this technique to more deeply understand the general diffuse background radiation over the sky."

NASA funded this research. The team hopes the agency will underwrite further investigations.

"We have submitted a proposal to NASA to use FUSE over the next year to explore the ramifications of our surprise discovery that FUSE can detect diffuse emission," Henry said. "By choosing targets carefully, we can get more easily interpreted data, allowing stronger conclusions regarding the nature of interstellar dust. The observed cosmic background is not fully understood and possibly is of new cosmological importance. We are confident that with FUSE and carefully implemented further observations, we can answer many questions for the first time."

The team’s paper on its observations of Orion has been accepted for publication by the Astrophysical Journal.

Designed and operated by a team of engineers and scientists at Johns Hopkins, FUSE is the largest astrophysics mission NASA has ever handed off to a university to manage. The 18-foot tall, 3,000 pound satellite has operated for five years from its perch 475 miles above the Earth’s surface, gathering unique data about everything from planets and nearby stars to galaxies and quasars billions of light years away.

Lisa DeNike | EurekAlert!
Further information:
http://www.jhu.edu
http://henry.pha.jhu.edu/orion.html

More articles from Physics and Astronomy:

nachricht Neutron star merger directly observed for the first time
17.10.2017 | University of Maryland

nachricht Breaking: the first light from two neutron stars merging
17.10.2017 | American Association for the Advancement of Science

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>