Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

X-Rays From a Reborn Planetary Nebula

19.11.2012
These images of the planetary nebula Abell 30, (a.k.a. A30), show one of the clearest views ever obtained of a special phase of evolution for these objects.

The inset image on the right is a close-up view of A30 showing X-ray data from NASA's Chandra X-ray Observatory in purple and Hubble Space Telescope (HST) data showing optical emission from oxygen ions in orange.


Inset X-ray (NASA/CXC/IAA-CSIC/M.Guerrero et al); Inset Optical (NASA/STScI); Widefield X-ray (ESA/XMM-Newton); Widefield Optical (NSF/NOAO/KPNO)

The planetary nebula Abell 30, (a.k.a. A30), is located about 5500 light years from Earth. The inset image on the right is a close-up view of A30 showing X-ray data from NASA's Chandra X-ray Observatory in purple and Hubble Space Telescope data showing optical emission from oxygen ions in orange. On the left is a larger view showing optical and X-ray data from the Kitt Peak National Observatory and ESA's XMM-Newton, respectively, where the optical data shows emission from oxygen (orange) and hydrogen (green and blue), and X-ray emission is colored purple. A planetary nebula is formed in the late stage of the evolution of a sun-like star, after it expands to become a red giant. In the case of A30, a planetary nebula formed but then the star briefly reverted to being a red giant. The evolution of the planetary nebula then restarted, making it reborn, a special phase of evolution that is rarely seen.

On the left is a larger view showing optical and X-ray data from the Kitt Peak National Observatory and ESA's XMM-Newton, respectively. In this image the optical data show emission from oxygen (orange) and hydrogen (green and blue), and X-ray emission is colored purple.

A planetary nebula – so called because it looks like a planet when viewed with a small telescope – is formed in the late stage of the evolution of a sun-like star.

After having steadily produced energy for several billion years through the nuclear fusion of hydrogen into helium in its central region, or core, the star undergoes a series of energy crises related to the depletion of hydrogen and subsequent contraction of the core. These crises culminate in the star expanding a hundred-fold to become a red giant.

Eventually the outer envelope of the red giant is ejected and moves away from the star at a relatively sedate speed of less than 100,000 miles per hour. The star meanwhile is transformed from a cool giant into a hot, compact star that produces intense ultraviolet (UV) radiation and a fast wind of particles moving at about 6 million miles per hour. The interaction of the UV radiation and the fast wind with the ejected red giant envelope creates the planetary nebula, shown by the large spherical shell in the bigger image.

In rare cases, nuclear fusion reactions in the region surrounding the star’s core heat the outer envelope of the star so much that it temporarily becomes a red giant again. The sequence of events - envelope ejection followed by a fast stellar wind - is repeated on a much faster scale than before, and a small-scale planetary nebula is created inside the original one. In a sense, the planetary nebula is reborn.

The large nebula seen in the larger image has an observed age of about 12,500 years and was formed by the initial interaction of the fast and slow winds. The cloverleaf pattern of knots seen in both images, correspond to the recently ejected material. These knots were produced much more recently, as they have an observed age of about 850 years, based on observations of their expansion using HST.

The diffuse X-ray emission seen in the larger image and in the region around the central source in the inset is caused by interactions between wind from the star and the knots of the ejected material. The knots are heated and eroded by this interaction, producing X-ray emission. The cause of the point-like X-ray emission from the central star is unknown.

Studies of A30 and other planetary nebulas help improve our understanding of the evolution of sun-like stars as they near the end of their lifetime. The X-ray emission reveals how the material lost by the stars at different evolutionary stages interact with each another. These observations of A30, located about 5500 light years away, provide a picture of the harsh environment that the solar system will evolve towards in several billion years, when the sun's strong stellar wind and energetic radiation will blast those planets that survived the previous, red giant phase of stellar evolution.

The structures seen in A30 originally inspired the idea of reborn planetary nebulas, and only three other examples of this phenomenon are known. A new study of A30, using the observatories mentioned above, has been reported by an international team of astronomers in the August 20th, 2012 issue of The Astrophysical Journal. The paper is available at http://lanl.arxiv.org/abs/1202.4463

The first author of the paper reporting these results is Martín A. Guerrero of the Instituto de Astrofísica de Andalucía (IAA-CSIC) in Spain. The other authors are N. Ruiz, also from the IAA-CSIC, Spain; W.-R. Hamann, from the University of Potsdam, Germany; Y.-H. Chu, from the University of Illinois, Urbana, IL; H. Todt, from the University of Potsdam, Germany; D. Schönberner, from the Leibniz-Institut Für Astrophysik in Potsdam, Germany; L. Oskinova, from the University of Potsdam, Germany; R. Gruendl, from the University of Illinois, Urbana, IL; M. Steffen, from the Leibniz-Institut Für Astrophysik in Potsdam, Germany; W. Blair, from Johns Hopkins University in Baltimore, MD and J. Toalá from the IAA-CSIC, Spain.

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

Megan Watzke | Newswise Science News
Further information:
http://www.cfa.harvard.edu

More articles from Physics and Astronomy:

nachricht Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication
16.07.2018 | Chinese Academy of Sciences Headquarters

nachricht Theorists publish highest-precision prediction of muon magnetic anomaly
16.07.2018 | DOE/Brookhaven National Laboratory

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Research finds new molecular structures in boron-based nanoclusters

13.07.2018 | Materials Sciences

Algae Have Land Genes

13.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>