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domingo, 22 de febrero de 2015

NASA : Exploded Star Blooms Like a Cosmic Flower .- Despiece estrella Blooms como una flor cósmica

Hola amigos: A VUELO DE UN QUINDE EL BLOG., hemos recibido de la Agencia Espacial NASA, la espectacular vista de una Supernova Type Ia G299.
NASA, nos dice : "G299 fue dejado por una clase particular de las supernovas llamada de tipo Ia . Los astrónomos piensan que una supernova de tipo Ia;  es una explosión termonuclear, que  implica la fusión de elementos y la liberación de grandes cantidades de energía; de una estrella enana blanca en una órbita apretada con una estrella compañera. Si la pareja de la enana blanca es un típico, como el Sol de la estrella, la enana blanca puede llegar a ser inestable y estalla ya que llama la materia de su compañera. Alternativamente, la enana blanca está en órbita con otra enana blanca, los dos pueden fusionarse y puede provocar una explosión........"

Exploded Star Blooms Like a Cosmic Flower
G299 was left over by a particular class of supernovas called Type Ia.  Astronomers think that a Type Ia supernova is a thermonuclear explosion – involving the fusion of elements and release of vast amounts of energy − of a white dwarf star in a tight orbit with a companion star. If the white dwarf’s partner is a typical, Sun-like star, the white dwarf can become unstable and explode as it draws material from its companion. Alternatively, the white dwarf is in orbit with another white dwarf, the two may merge and can trigger an explosion.
Image Credit: NASA/CXC/U.Texas
 
 
G299.2-2.9, a Middle-Aged Supernova Remnant
10.12.11
Composite image of G299.2.2.9, an intriguing supernova remnant

G299.2-2.9 is an intriguing supernova remnant found about 16,000 light years away in the Milky Way galaxy. Evidence points to G299.2-2.9 being the remains of a Type Ia supernova, where a white dwarf has grown sufficiently massive to cause a thermonuclear explosion. Because it is older than most supernova remnants caused by these explosions, at an age of about 4,500 years, G299.2-2.9 provides astronomers with an excellent opportunity to study how these objects evolve over time. It also provides a probe of the Type Ia supernova explosion that produced this structure.

This composite image shows G299.2-2.9 in X-ray light from Chandra and the ROSAT satellite, in orange, that has been overlaid on an infrared image from the Two Micron All-Sky Survey, or 2MASS. The faint X-ray emission from the inner region reveals relatively large amounts of iron and silicon, as expected for a remnant of a Type Ia supernova. The outer shell of the remnant is complex, with at least a double shell structure. Typically, such a complex outer shell is associated with a star that has exploded into space where gas and dust are not uniformly distributed.

Since most theories to explain Type Ia supernovas assume they go off in a uniform environment, detailed studies of this complicated outer shell should help astronomers improve their understanding of the environments where these explosions occur. It is very important to understand the details of Type Ia explosions because astronomers use them as cosmic mile markers to measure the accelerated expansion of the universe and study dark energy. The discovery of this accelerated expansion in the late 1990s led to the recent award of the Nobel Prize in Physics.

Credits: X-ray: NASA/CXC/U.Texas/S. Park et al, ROSAT; Infrared: 2MASS/UMass/IPAC-Caltech/NASA/NSF

> Read more/access all images
 
Janet Anderson, 256-544-0034
Marshall Space Flight Center, Huntsville, Ala.
janet.l.anderson@nasa.gov

Megan Watzke 617-496-7998
Chandra X-ray Center, Cambridge, Mass.
m.watzke@cfa.harvard.edu
NASA
Guillermo Gonzalo Sánchez Achutegui
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