Featured Research

from universities, journals, and other organizations

Cosmic dust belts without dust

Date:
July 8, 2013
Source:
Friedrich Schiller University Jena
Summary:
Planets and asteroids, red giants and brown dwarfs – there are all kinds of objects in our Universe. Debris disks are among them. These are belts consisting of countless dust particles and planetesimals, circling around one central star. Debris disks are an important piece in the puzzle to be able to better understand the variety of planetary systems.

Planets and asteroids, red giants and brown dwarfs -- there are all kinds of objects in our Universe. Debris disks are among them. These are belts consisting of countless dust particles and planetesimals, circling around one central star. "At least one fifth of stars are surrounded by dust belts like these," Prof. Dr. Alexander Krivov from the Friedrich-Schiller-University Jena explains. "They are the remains of the formation of planets, in which the unused, building materials are collected," the astrophysicist points out. Therefore debris disks are an important piece in the puzzle to be able to better understand the variety of planetary systems.

Related Articles


For astronomers like Alexander Krivov debris disks are actually nothing new. Our sun is also orbited by such dust belts: the Asteroid Belt and the Kuiper Belt with Pluto being perhaps the most well-known object in it. However, the Jena astrophysicist, accompanied by an international team of scientists, has observed six stars similar to the sun with extraordinary dust belts: The newly discovered debris disks are not only bigger than the Kuiper Belt. Above all they are extremely cold. With a temperature of about minus 250 °C they are the coldest debris disks known so far. The scientists report on it in the science journal 'The Astrophysical Journal', which is already online and will be available in a print version from 20 July. "We were surprised that such cold debris disks exist at all," Alexander Krivov, the lead author of the new study, says. By way of comparison: The Kuiper Belt is about 70 °C degree warmer, some of the dust disks even reach room temperature.

The six debris disks are mysterious for yet another reason: They are lacking the characteristic dust which is always released when the rocks collide. "Small dust particles are much hotter than the temperatures observed by us," Krivov says. According to this, the cold debris disks only consist of bigger but at the same time not-too-big rocks. The calculations of the scientists suggest that the radius of the particles lies between several millimeters and several kilometers maximum. "If there were any bigger objects, the disks would be much more dynamic, the bodies would collide and thereby generate dust," the Jena professor of astrophysics explains. The cold debris disks are admittedly a relic of its former planet factory, but the growth to the size of planets stopped early on -- even before bodies the size of asteroids or even dwarf planets could develop. "We don't know why the development stopped," Krivov says. "But the cold debris disks are proof that such belts can exist for over billions of years."

The scientists came across the unusual debris disks with the help of the Herschel Space Observatory -- the largest telescope that was ever launched into space. "Herschel was especially designed to detect cold objects, because it has measured the radiation in far infrared," Prof. Krivov explains. In spite of its enormous effectiveness the observation of the cold debris disks was a demanding task even for Herschel. Thus scientists cannot rule out the possibility that the supposed debris disks could actually be background galaxies which just happen to be behind the central star. "Our studies however show that there is a high likelihood we are mostly dealing with real disks," Krivov states. As planned, Herschel entered retirement in April. The scientists reckon that they will gain final certainty about their findings with the help of data by further instruments like the radio telescope ALMA in the Chilean Atacama Desert.


Story Source:

The above story is based on materials provided by Friedrich Schiller University Jena. Note: Materials may be edited for content and length.


Journal Reference:

  1. A. V. Krivov, C. Eiroa, T. Löhne, J. P. Marshall, B. Montesinos, C. del Burgo, O. Absil, D. Ardila, J.-C. Augereau, A. Bayo, G. Bryden, W. Danchi, S. Ertel, J. Lebreton, R. Liseau, A. Mora, A. J. Mustill, H. Mutschke, R. Neuhäuser, G. L. Pilbratt, A. Roberge, T. O. B. Schmidt, K. R. Stapelfeldt, Ph. Thébault, Ch. Vitense, G. J. White, S. Wolf. HERSCHEL's “COLD DEBRIS DISKS”: BACKGROUND GALAXIES OR QUIESCENT RIMS OF PLANETARY SYSTEMS? The Astrophysical Journal, 2013; 772 (1): 32 DOI: 10.1088/0004-637X/772/1/32

Cite This Page:

Friedrich Schiller University Jena. "Cosmic dust belts without dust." ScienceDaily. ScienceDaily, 8 July 2013. <www.sciencedaily.com/releases/2013/07/130708102936.htm>.
Friedrich Schiller University Jena. (2013, July 8). Cosmic dust belts without dust. ScienceDaily. Retrieved March 27, 2015 from www.sciencedaily.com/releases/2013/07/130708102936.htm
Friedrich Schiller University Jena. "Cosmic dust belts without dust." ScienceDaily. www.sciencedaily.com/releases/2013/07/130708102936.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

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
Opportunity's Marathon: The Mars Rover Just Keeps Going

Opportunity's Marathon: The Mars Rover Just Keeps Going

Newsy (Mar. 24, 2015) — NASA&apos;s Opportunity Mars Rover finished a full marathon, making it the first human creation to do a full 26.2 miles on another planet. Video provided by Newsy
Powered by NewsLook.com
Twin Astronaut to Break NASA Record in Study

Twin Astronaut to Break NASA Record in Study

AP (Mar. 23, 2015) — NASA astronaut Scott Kelly will be the first American to spend a year aboard the International Space Station in an experiment to test human endurance in space, while his twin brother&apos;s health is compared on Earth. (March 23) Video provided by AP
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