Featured Research

from universities, journals, and other organizations

Astronomers Find Nebula Appears Larger Than It Is

Date:
January 19, 2000
Source:
Virginia Tech
Summary:
Astronomers from Virginia Tech announced on Thursday, Jan. 13, at the American Astronomical Society (AAS) meeting in Atlanta that a well-known, luminous cloud of gas in our galaxy called the Rosette Nebula is actually smaller than it appears.

BLACKSBURG, Va., Jan. 13, 2000 -- Astronomers from Virginia Tech announced on Thursday, Jan. 13, at the American Astronomical Society (AAS) meeting in Atlanta that a well-known, luminous cloud of gas in our galaxy called the Rosette Nebula is actually smaller than it appears.

Related Articles


Greg Topasna, a recent Ph.D. graduate of Virginia Tech, and Professors Brian Dennison and John Simonetti used a special camera tuned to detect a particular wavelength of light emitted by hydrogen atoms, much like a radio tuned to receive a particular station. Astronomers refer to this light from hydrogen as H-alpha. When they pointed their camera at the Rosette Nebula, they discovered that it appears larger than it actually is. The illusion is caused by scattering of H-alpha light from a dust shell surrounding the nebula, the astronomers said. This discovery means that when H-alpha light is used to view nebulae, one must take into consideration that their larger appearance may be an illusion caused by scattered light.

A related process occurs in the Earth's atmosphere, Topasna said. The sky looks bright during the day, he said, because sunlight is scattered from molecules and particles in the atmosphere. This is analogous to the Rosette Nebula, he said, because some of the light emitted in the hot core of the nebula is scattered by its surrounding shell.

The Rosette Nebula in the constellation Monoceros is about 5000 light years from Earth and can be seen with a modest telescope. It has a symmetrical rose-like appearance, which gives it its name. A cluster of hot stars heats gas within the nebulaΉs core to nearly 18,000 degrees Fahrenheit. The gas is so hot that it emits light, much like a fluorescent tube. Much of the light emitted in the Rosette nebula is H-alpha light from hydrogen atoms.

The Virginia Tech scientists used a special camera that they developed to detect H-alpha light and light from other atoms in space. The camera is located at a dark mountain site at Virginia Tech's Horton Research Center in Southwest Virginia. Topasna modified the camera to detect polarization of the light.

"When we found strong polarization in the H-alpha light from what appeared to be the outer parts of the Rosette Nebula, I knew we were onto something," he said. "Just as scattered sunlight from the daylight sky is polarized, we found that scattering in the dust shell surrounding the Rosette Nebula also causes polarization." Polarization is a common phenomenon usually present when light is scattered, the astronomers said, and many brands of sunglasses use this property of scattered light to reduce glare. Topasna already has evidence that similar effects are seen around other bright nebulae, such as the North America Nebula, so-called because of its crude resemblance to North America.

The trio is carrying out a highly sensitive survey of hydrogen gas between the stars. Their camera produces digital images that can be manipulated in a computer. Topasna, who implemented, the polarization technique for his Ph.D. thesis, will present his results at the AAS meeting in Atlanta Jan. 13.

###

Note to editors/reporters: A low-resolution image is available at: http://www.rgs.vt.edu/resmag/rosette.gif


Story Source:

The above story is based on materials provided by Virginia Tech. Note: Materials may be edited for content and length.


Cite This Page:

Virginia Tech. "Astronomers Find Nebula Appears Larger Than It Is." ScienceDaily. ScienceDaily, 19 January 2000. <www.sciencedaily.com/releases/2000/01/000119075516.htm>.
Virginia Tech. (2000, January 19). Astronomers Find Nebula Appears Larger Than It Is. ScienceDaily. Retrieved March 27, 2015 from www.sciencedaily.com/releases/2000/01/000119075516.htm
Virginia Tech. "Astronomers Find Nebula Appears Larger Than It Is." ScienceDaily. www.sciencedaily.com/releases/2000/01/000119075516.htm (accessed March 27, 2015).

Share This


More From ScienceDaily



More Space & Time News

Friday, March 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Why So Many People Think NASA's Asteroid Mission Is A Waste

Why So Many People Think NASA's Asteroid Mission Is A Waste

Newsy (Mar. 27, 2015) — The Asteroid Retrieval Mission announced this week bears little resemblance to its grand beginnings. Even NASA scientists are asking, "Why bother?" Video provided by Newsy
Powered by NewsLook.com
Robot Returns from International Space Station and Sets Two Guinness World Records

Robot Returns from International Space Station and Sets Two Guinness World Records

Reuters - Light News Video Online (Mar. 27, 2015) — The companion robot "Kirobo" returns to earth from the International Space Station and sets two Guinness World Records. Sharon Reich reports. Video provided by Reuters
Powered by NewsLook.com
Supermassive Blackhole Detector Ready for Business

Supermassive Blackhole Detector Ready for Business

Reuters - Innovations Video Online (Mar. 25, 2015) — Construction of the world&apos;s largest and most powerful observatory designed to detect and analyze gamma rays has been completed in Mexico. Gamma ray particles are considered the most energetic in the universe and scientists hope to use the observatory to learn more about the supernovas and black holes that produce them. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Rocket Blasts Off Carrying U.S. Air Force GPS Satellite

Rocket Blasts Off Carrying U.S. Air Force GPS Satellite

Reuters - News Video Online (Mar. 25, 2015) — A U.S. Air Force GPS IIF-9 satellite launches aboard a United Launch Alliance Delta IV rocket into semi-synchronous orbit. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins