Supernova Remnant Turns 400
Four hundred years ago, sky watchers, including the famous astronomer Johannes Kepler, were startled by the sudden appearance of a “new star” in the western sky, rivaling the brilliance of the nearby planets. Now, astronomers using NASA’s three Great Observatories are unraveling the mysteries of the expanding remains of Kepler’s supernova, the last such object seen to explode in our Milky Way galaxy.
This combined image — from NASA’s Spitzer Space Telescope, Hubble Space Telescope, and e Chandra X-ray Observatory — unveils a bubble-shaped shroud of gas and dust that is 14 light-years wide and is expanding at 4 million miles per hour (2,000 kilometers per second). Observations from each telescope highlight distinct features of the supernova remnant, a fast-moving shell of iron-rich material from the exploded star, surrounded by an expanding shock wave that is sweeping up interstellar gas and dust.
Given the idea that there is an original version to what is constituted as reality and attempts to describe it are really, “Births by approximation.”
Now you have to understand the previous blog posting by this name to understand that I presented supernovas and remnants as a illustration of what happens when we see the universe by itself, is laid out before us, while within that time frame (universe’s birth to present), events have happened that are defined as Supernovas.
Several types of supernovae exist that may be triggered in one of two ways, involving either turning off or suddenly turning on the production of energy through nuclear fusion. After the core of an aging massive star ceases to generate energy from nuclear fusion, it may undergo sudden gravitational collapse into a neutron star or black hole, releasing gravitational potential energy that heats and expels the star’s outer layers.
Now in terms of what we now know in what has been demonstrated by being lead by scientific process, a realization that such events as “the Spherical cow embeds parts of the universe in expression.” We now know that such a view in terms of 13.7 billion years in the universe’s age, has elements within it that are aged as well which should not exceed the age of the universe? How does gravity occur in the totality of the whole universe, for it not to be the same, as the Supernova unfolds.
Within a massive, evolved star (a) the onion-layered shells of elements undergo fusion, forming an iron core (b) that reaches Chandrasekhar-mass and starts to collapse. The inner part of the core is compressed into neutrons (c), causing infalling material to bounce (d) and form an outward-propagating shock front (red). The shock starts to stall (e), but it is re-invigorated by a process that may include neutrino interaction. The surrounding material is blasted away (f), leaving only a degenerate remnant.
Stars with at least nine solar masses of material evolve in a complex fashion. In the core of the star, hydrogen is fused into helium and the thermal energy released creates an outward pressure, which maintains the core in hydrostatic equilibrium and prevents collapse.
When the core’s supply of hydrogen is exhausted, this outward pressure is no longer created. The core begins to collapse, causing a rise in temperature and pressure which becomes great enough to ignite the helium and start a helium-to-carbon fusion cycle, creating sufficient outward pressure to halt the collapse. The core expands and cools slightly, with a hydrogen-fusion outer layer, and a hotter, higher pressure, helium-fusion center. (Other elements such as magnesium, sulfur and calcium are also created and in some cases burned in these further reactions.)
The event itself and the resulting explosion has to have a basis in terms of geometrics. What shall we call these Supernovas when their previous existence may have been a blackhole? What do we call stars that collapse that make blackholes.
Stars shine by burning hydrogen. The process is called nuclear fusion. Hydrogen burning produces helium “ash.” As the star runs out of hydrogen (and nears the end of its life), it begins burning helium. The ashes of helium burning, such as carbon and oxygen, also get burned. The end result of this fusion is iron. Iron cannot be used for nuclear fuel. Without fuel, the star no longer has the energy to support its weight. The core collapses. If the star is massive enough, the core will collapse into a black hole. The black hole quickly forms jets; and shock waves reverberating through the star ultimately blow apart the outer shells. Gamma-ray bursts are the beacons of star death and black hole birth.
Bold emphasis to encourage a conclusive realization about the classification of those events within the universe given to Gamma recordings in our measures.
Hybrids in the Universe?-12.20.06X-ray image of the gamma-ray burst GRB 060614 taken by the XRT instrument on Swift. The burst glowed in X-ray light for more than a week following the gamma-ray burst. This so-called “afterglow” gave an accurate position of the burst on the sky and enabled the deep optical observations made by ground-based observatories and the Hubble Space Telescope. Credit: NASA/Swift Team
A year ago scientists thought they had figured out the nature of gamma-ray bursts. They signal the birth of black holes and traditionally, fall into one of two categories: long or short. A newly discovered hybrid burst has properties of both known classes of gamma-ray bursts yet possesses features that remain unexplained.
The long bursts are those that last more than two seconds. It is believed that they are ejected by massive stars at the furthest edge of the universe as they collapse to form black holes.