Featured Research

from universities, journals, and other organizations

Disc Of Silicates Found In Heart Of Magnificent Ant Nebula

Date:
October 3, 2007
Source:
ESO
Summary:
Using ESO's Very Large Telescope Interferometer and its unique ability to see small details, astronomers have uncovered a flat, nearly edge-on disc of silicates in the heart of the magnificent Ant Nebula. The disc seems, however, too 'skinny' to explain how the nebula got its intriguing ant-like shape.

Using ESO's Very Large Telescope Interferometer, astronomers have uncovered a disc in the heart of the Ant Nebula. The disc seems, however, too 'skinny' to explain how the nebula got its intriguing ant-like shape. The image on the right shows a previously taken image of the Ant Nebula, in the mid-infrared, with the VLT Imager and Spectrometer for the mid-InfraRed (VISIR) (see ESO Press Photo 16e/04). The image on the left shows a model of the dusty disc the astronomers uncovered with the MID-infrared Interferometric instrument (MIDI), which combined the light from two 8.2-m VLT Unit Telescopes. The lower part of the image representing the southern lobe is brighter, for this lobe is closer to our line-of-sight. The major axis of the flat, nearly edge-on disc is perpendicular to the axis of the bipolar lobes of the nebula. The disc extends from about 9 times the mean distance between the Earth and the Sun (9 Astronomical Units or 9 AU) to more than 500 AU.
Credit: Copyright Stephane Guisard, ESO

Using ESO's Very Large Telescope Interferometer and its unique ability to see small details, astronomers have uncovered a flat, nearly edge-on disc of silicates in the heart of the magnificent Ant Nebula. The disc seems, however, too 'skinny' to explain how the nebula got its intriguing ant-like shape.

Related Articles


The Ant Nebula is one of the most striking planetary nebulae known. Planetary nebulae - whose name arises because most are spherical and looked like planets when they were first discovered through older, less powerful telescopes - are glowing structures of gas cast off by solar-like stars at the ends of their lives. The morphology of the Ant Nebula - a bright core, three nested pairs of bipolar lobes and a ring-like outflow - is so unique that it was nicknamed the 'Chamber of Horrors' of planetary nebulae in the late 1950s.

But how can a spherical star produce such complex structures? The answer, many astronomers think, requires understanding of the discs surrounding the central star. By their nature, these discs bear witness to the phenomena that lead to the asymmetrical structures of planetary nebulae.

"The challenge is to actually detect these discs," explains team leader Olivier Chesneau, from the Observatoire de la Cτte d'Azur, France. "Most astronomical instruments do not have a sharp enough view to find, let alone study them. The Very Large Telescope Interferometer however, with its exceptionally high spatial resolution, is a powerful disc-hunter."

The disc of the Ant Nebula, which cannot be detected with a single 8.2-m VLT Unit Telescope, was uncovered in the interferometric mode where two 8.2-m Unit Telescopes were used to combine light, through the MID-infrared Interferometric instrument (MIDI). The observations reveal a flat, nearly edge-on disc whose major axis is perpendicular to the axis of the bipolar lobes.

The disc extends from about 9 times the mean distance between the Earth and the Sun (9 Astronomical Units or 9 AU) to more than 500 AU. At the distance of the Ant Nebula, this corresponds to having detected structures that subtend an angle of only 6 milli-arcseconds. This is similar to distinguishing a two-storey building on the Moon.

The dust mass stored in the disc appears to be only one hundred thousandth the mass of the Sun and is a hundred times smaller than the mass found in the bipolar lobes.

"We must therefore conclude that the disc is too light to have a significant impact on the outflowing material and cannot explain the shape of the Ant Nebula", says Chesneau. "Instead, it looks more like this disc is some remnant of the material expelled by the star."

The observations also provide unquestionable evidence that the disc is primarily composed of amorphous silicate. "This," says Chesneau, "most likely indicates that the disc is young, perhaps as young as the planetary nebula itself."

The astronomers favour the possibility that the large quantity of material in the lobes was propelled by several large-scale events, triggered with the help of a cool stellar companion. The solution of the mystery thus resides in the core of the system, and requires better characterisation of the hot central star and its putative companion, currently hidden from our view by the dusty disc.

The results are presented in a Letter to the Editor published by the research journal Astronomy and Astrophysics ("A silicate disk in the heart of the Ant" by O. Chesneau et al.).

The team is composed of O. Chesneau and A. Spang (Observatoire de la Cτte d'Azur, France), F. Lykou, E. Lagadec, and A.A. Zijlstra (University of Manchester, UK), B. Balick (University of Washington, Seattle, USA), M. Matsuura (NAOJ, Tokyo, Japan), N. Smith (University of California, USA), and S. Wolf (Max-Planck-Institute for Astronomy, Heidelberg, Germany).


Story Source:

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


Cite This Page:

ESO. "Disc Of Silicates Found In Heart Of Magnificent Ant Nebula." ScienceDaily. ScienceDaily, 3 October 2007. <www.sciencedaily.com/releases/2007/09/070927113205.htm>.
ESO. (2007, October 3). Disc Of Silicates Found In Heart Of Magnificent Ant Nebula. ScienceDaily. Retrieved November 24, 2014 from www.sciencedaily.com/releases/2007/09/070927113205.htm
ESO. "Disc Of Silicates Found In Heart Of Magnificent Ant Nebula." ScienceDaily. www.sciencedaily.com/releases/2007/09/070927113205.htm (accessed November 24, 2014).

Share This


More From ScienceDaily



More Space & Time News

Monday, November 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Soyuz Spacecraft Docks With International Space Station: NASA

Soyuz Spacecraft Docks With International Space Station: NASA

AFP (Nov. 24, 2014) — A Russian Soyuz spacecraft carrying Italy's first female astronaut safely docks with the International Space Station, according to NASA. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Multi-National Crew Safely Docks at Space Station

Multi-National Crew Safely Docks at Space Station

Reuters - US Online Video (Nov. 24, 2014) — A Russian Soyuz rocket delivers a multi-national trio to the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Raw: Soyuz Docks With Int'l Space Station

Raw: Soyuz Docks With Int'l Space Station

AP (Nov. 23, 2014) — A Russian capsule carrying three astronauts from Russia, the United States and Italy has arrived at the International Space Station. (Nov. 23) Video provided by AP
Powered by NewsLook.com
Raw: Crew Blasts Off for Int'l Space Station

Raw: Crew Blasts Off for Int'l Space Station

AP (Nov. 23, 2014) — A Russian capsule carrying three astronauts from Russia, the United States and Italy has blasted off for the International Space Station. (Nov. 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