The Helix Nebula, NGC 7293, lies about 700 light-years away in the constellation of Aquarius (the Water Bearer).
It is one of the closest and most spectacular examples of a planetary nebula. These exotic objects have nothing to do with planets, but are the final blooming of Sun-like stars before their retirement as white dwarfs.
Shells of gas are blown off from a star’s surface, often in intricate and beautiful patterns, and shine under the harsh ultraviolet radiation from the faint, but very hot, central star. The main ring of the Helix Nebula is about two light-years across or half the distance between the Sun and its closest stellar neighbour.
Despite being photographically very spectacular the Helix is hard to see visually as its light is thinly spread over a large area of sky and the history of its discovery is rather obscure. It first appears in a list of new objects compiled by the German astronomer Karl Ludwig Harding in 1824. The name Helix comes from the rough corkscrew shape seen in the earlier photographs.
Although the Helix looks very much like a doughnut, studies have shown that it possibly consists of at least two separate discs with outer rings and filaments. The brighter inner disc seems to be expanding at about 100 000 km/h and to have taken about 12 000 years to have formed.Because the Helix is relatively close — it covers an area of the sky about a quarter of the full Moon — it can be studied in much greater detail than most other planetary nebulae and has been found to have an unexpected and complex structure. All around the inside of the ring are small blobs, known as “cometary knots”, with faint tails extending away from the central star. They look remarkably like droplets of liquid running down a sheet of glass.
Dr. Henri Boffin | EurekAlert!
Further reports about: > Aquarius > ESO's La Silla Observatory > Helix > Helix Nebula > Sun-like stars > Telescope > Water Bearer > cometary knots > distant galaxies > light-years > magnificent Helix planetary nebula > nebula > planetary nebula > stellar neighbour > ultraviolet radiation > white dwarfs
From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison
Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
23.02.2017 | Physics and Astronomy
23.02.2017 | Earth Sciences
23.02.2017 | Life Sciences