Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




EXO WORLDS
A Reborn Planetary Nebula
by Staff Writers
Huntsville, AL (SPX) Nov 16, 2012


illustration only

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.

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 first author of the paper reporting these results is Martin A. Guerrero of the Instituto de Astrofisica de Andalucia (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. Schonberner, from the Leibniz-Institut Fur 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 Fur Astrophysik in Potsdam, Germany; W. Blair, from Johns Hopkins University in Baltimore, MD and J. Toala 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.

Credits: 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)

.


Related Links
Chandra at NASA
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





EXO WORLDS
Lonely planet: Orphan world spotted in deep space
Paris (AFP) Nov 14, 2012
Astronomers on Wednesday reported they had detected a planet that had strayed from its star system and was wandering alone in deep space. Object CFBDSIR2149 is believed to be a cold, young world that for unknown reasons has pulled free of the gravitational pull of its mother star, the European Southern Observatory (ESO) said. It is not the first time that a "free-floating" planet has bee ... read more


EXO WORLDS
China's Chang'e-3 to land on moon next year

Moon crater yields impact clues

Study: Moon basin formed by giant impact

NASA's LADEE Spacecraft Gets Final Science Instrument Installed

EXO WORLDS
Mars radiation levels not lethal to humans

NASA Rover Providing New Weather and Radiation Data About Mars

Rover's 'SAM' Lab Instrument Suite Tastes Soil

Survey At 'Matijevic Hill' Wrapping Up

EXO WORLDS
SciTechTalk: All work and no play?

Get some bed rest - all 21 days of it

Latest China military hardware displayed at airshow

Obama Win Keeps NASA's Space Plans on Course

EXO WORLDS
Mr Xi in Space

China plans manned space launch in 2013: state media

China to launch manned spacecraft

Tiangong 1 Parked And Waiting As Shenzhou 10 Mission Prep Continues

EXO WORLDS
Space station command changes

Russia restores space contact after cable rupture

Russia loses contact with satellites, space station

Cut in Russian link to space station not serious: NASA

EXO WORLDS
Arianespace's fourth Spaceport mission with Soyuz ready for fueling

Ariane 5's sixth launch of 2012

Ariane 5 is poised for Arianespace's launch with the EUTELSAT 21B and Star One C3 satellites

Ariane 5 orbits EUTELSAT 21B and Star One C3 satellites

EXO WORLDS
Lowell astronomer, collaborators point the way for exoplanet search

A Reborn Planetary Nebula

Lost in Space: Rogue Planet Spotted?

Lowell Astronomer, Collaborators Point The Way For Exoplanet Search

EXO WORLDS
Andrews Space To Manufacture Sinclair Rods

Raytheon submits Space Fence proposal to the USAF

Larger version of Kindle Fire tablet unleashed

Lockheed Martin Submits Space Fence Radar Proposal to USAF to Detect and Track Orbital Objects




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement