Hola amigos: A VUELO DE UN QUINDE EL BLOG., la Agencia Espacial NASA, nos informa de la visión captada por NASA’s Chandra X-ray Observatory. de la explosión de una Supernova. haciendo la comparación tal como : En películas de Hollywood, explosiones suelen estar entre las estrellas del espectáculo. En el espacio, explosiones de estrellas reales son un foco para los científicos que esperan entender mejor sus nacimientos, vidas y muertes y la forma en que interactúan con su entorno.
Utilizando el Observatorio de Rayos X Chandra de la NASA, los astrónomos han estudiado una explosión particular que puede proporcionar pistas sobre la dinámica de otras erupciones estelares,
mucho más grandes.
Un equipo de investigadores señaló el telescopio a GK Persei, un objeto que se convirtió en una sensación en el mundo astronómico en 1901 cuando de repente apareció como una de las estrellas más brillantes en el cielo durante unos días, antes de desaparecer gradualmente en brillo. Hoy en día, los astrónomos citan GK Persei como un ejemplo de una "nova clásica", una explosión producida por una explosión termonuclear en la superficie de una estrella enana blanca, el denso remanente de una estrella similar al Sol.
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"Mini Supernova" Explosion Could Have Big Impact
In Hollywood blockbusters, explosions are often among the stars of the show.
In space, explosions of actual stars are a focus for scientists who hope to
better understand their births, lives, and deaths and how they interact with
their surroundings.
A team of researchers pointed the telescope at GK Persei, an object that
became a sensation in the astronomical world in 1901 when it suddenly appeared
as one of the brightest stars in the sky for a few days, before gradually fading
away in brightness. Today, astronomers cite GK Persei as an example of a
“classical nova,” an outburst produced by a thermonuclear explosion on the
surface of a white dwarf star, the dense remnant of a Sun-like star.
A nova can occur if the strong gravity of a white dwarf pulls material from
its orbiting companion star. If enough material, mostly in the form of hydrogen
gas, accumulates on the surface of the white dwarf, nuclear fusion reactions can
occur and intensify, culminating into a cosmic-sized hydrogen bomb blast. The
outer layers of the white dwarf are blown away, producing a nova outburst that
can be observed for a period of months to years as the material expands into
space.
Classical novas can be considered to be “miniature” versions of supernova
explosions. Supernovas signal the destruction of an entire star and can be so
bright that they outshine the whole galaxy where they are found. Supernovas are
extremely important for cosmic ecology because they inject huge amounts of
energy into the interstellar gas, and are responsible for dispersing elements
such as iron, calcium and oxygen into space where they may be incorporated into
future generations of stars and planets.
Although the remnants of supernovas are much more massive and energetic than
classical novas, some of the fundamental physics is the same. Both involve an
explosion and creation of a shock wave that travels at supersonic speeds through
the surrounding gas.
The more modest energies and masses associated with classical novas means
that the remnants evolve more quickly. This, plus the much higher frequency of
their occurrence compared to supenovas, makes classical novas important targets
for studying cosmic explosions.
Chandra first observed GK Persei in February 2000 and then again in November
2013. This 13-year baseline provides astronomers with enough time to notice
important differences in the X-ray emission and its properties.
This new image of GK Persei contains X-rays from Chandra (blue), optical data
from NASA’s Hubble Space Telescope (yellow), and radio data from the National
Science Foundation’s Very Large Array (pink). The X-ray data show hot gas and
the radio data show emission from electrons that have been accelerated to high
energies by the nova shock wave. The optical data reveal clumps of material that
were ejected in the explosion. The nature of the point-like source on the lower
left is unknown.
Over the years that the Chandra data span, the nova debris expanded at a
speed of about 700,000 miles per hour. This translates to the blast wave moving
about 90 billion miles during that period.
One intriguing discovery illustrates how the study of nova remnants can
provide important clues about the environment of the explosion. The X-ray
luminosity of the GK Persei remnant decreased by about 40% over the 13 years
between the Chandra observations, whereas the temperature of the gas in the
remnant has essentially remained constant, at about one million degrees Celsius.
As the shock wave expanded and heated an increasing amount of matter, the
temperature behind the wave of energy should have decreased. The observed fading
and constant temperature suggests that the wave of energy has swept up a
negligible amount of gas in the environment around the star over the past 13
years. This suggests that the wave must currently be expanding into a region of
much lower density than before, giving clues to stellar neighborhood in which GK
Persei resides.
A paper describing these results appeared in the March 10th issue of The
Astrophysical Journal. The authors were Dai Takei (RIKEN, Spring-8 Center
Japan), Jeremy Drake (Smithsonian Astrophysical Observatory), Hiroya Yamaguichi
(Goddard Space Flight Center), Patrick Slane (Smithsonian Astrophysical
Observatory), Yasunobu Uchimaya (Rikkyo University, Japan), Satoru Katsuda
(Japanese Aerospace Exploration Agency).
NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the
Chandra program for NASA's Science Mission Directorate in Washington. The
Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls
Chandra's science and flight operations.
Image Credit: NASA/CXC/RIKEN/D.Takei et
al
NASA
Guillermo Gonzalo Sánchez Achutegui
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