Nebula halo - spectacular results

Stars are not large enough to carry out supernova explosions that end their lives by blowing most of their weight in a high wind. Only the star's hot core exists as a white star; the rest dispersed into interstellar intermediate regions, enriching this space with elements that have undergone chemical alterations, such as carbon, the chemical found in all births. living things on Earth.

These elements are fired in the furnace, which is the star itself in its billions of years of life. High-energy radiation from white stars causes the air to be blown away for a short time, and the result is one of the most beautiful and most astronomical astronomical objects: planetary nebulae.

Complex history

The event that led to the formation of planetary nebulae developed in two stages that eventually formed a structure that contained a dense interior - the planetary nebula - and a dimmer outer halo, contains ionizing winds. This phenomenon occurs for a short time, in astronomical terms, and planetary nebulae can only be observed for a few thousand years. For that reason, there are not many such objects to study.

The outer halos of the planetary nebula are faint and difficult to study, but they can provide a great deal of information about the physical properties of the stellar loss of weight before turning off. Although there have been advances in understanding the development and weight loss of stars in theory, but detailed observations, especially the final stage of the weight loss process, are still very limited. Astronomical spectroscopes and other devices allow you to study certain characteristics of a fuzzy and large object, making it extremely difficult, or even impossible, to analyze the light above. OK.

Solution for integrating spectroscopy

Using the new technique of integrative spectroscopy, scientists can collect hundreds of spectra in a fairly large space, which opens new perspectives for the analysis of large objects, such as planetary nebulae. The Calar Alto Observatory has one of the best integral spectrophotometers in the world, PMAS (Potsdam Multi-Aperture Spectrophotometer), attached to a telescope.

IC 3568 (Photo: Howard Bond (STScI), NASA)

In a new article, published in the journal Astronomy and Astrophysics, a research group from the Potsdam Astronomical Academy, led by C. Sandin, used PMAS to study the two-dimensional structure of a group of 5 crystals. Planetary vein in our galaxy: Blue Snowball nebula (NGC 7662), M2-2, IC 3568, Blinking planetary nebula (NGC 6826) and Owl nebula (NGC 3587).

The halo of the planetary nebula is revealed

For 4 of the aforementioned objects, the team built a temperature structure, extending from the central star to the outer glow. They found that in 3 cases the temperature increased suddenly inside the halos. According to Sandin: 'The presence of such a hot halo can be explained as a brief phenomenon that occurs when the halo is ionized' . A remarkable result of that study was that they had for the first time determined the history of the weight loss process in the last evolution of the star, and from which the planetary nebula was formed.

Sandin said: 'Compared to other methods, measuring the rate of star weight loss, our calculations are performed directly on the gas composition in stellar winds'. These results provide an important understanding of the gradual loss of weight over time, and the researchers found that 'weight loss rates increase due to a factor of 4-7 in the last 10,000 years. same ' . The team plans to continue studying the final evolution of low-weight stars. They observed the planetary nebula at the Magellanic Cloud. The authors argue that 'theoretically the results of this study provide the basis for the advancement of the wind patterns of stars'.