High-Z Supernova Search
Table of ContentsThe Expanding Universe
The Fate of the Universe
Supernovae [1] [2] [3] [4] [5]
Type Ia Supernovae
Searching for Distant Type Ia Supernovae
Search Results
Search Conclusions
Supernovae
Stars more massive than the Sun also condense from clouds of dust and gas, but they burn their Hydrogen more quickly and radiate more brightly than the Sun. The most massive stars have much shorter lives. For example, a star with 100 times more hydrogen than the Sun fuses it a 100,000 times faster and exhausts it 1,000 times sooner. It then commences Helium fusion, and swells to a Red Super Giant with a diameter that could encompass the orbit of Mars. Its Helium soon runs out, but the temperature and pressure in the core is high enough for Carbon, Oxygen, and successively heavier elements to fuse, releasing even more energy. While the core contains elements which fuse with the release of energy, its nuclear furnace continues to rage. But, each successive conversion releases less total energy, and fuels the star's furnace for a shorter time. The last few days of the star's 10 million year life are spent fusing Silicon into Iron.
Iron can fuse to form heavier elements such as Cobalt and Nickel,
but to occur, the reaction requires an input of energy.
Once the massive star's core consists entirely of iron, fusion ceases.
That turns off the heat source keeping the material of the star's core in motion.
The core cools, and the force of gravity causes the core to collapse.
The heat and pressure generated by compression fuels the fusion of heavier
elements. Shock waves rebound in the collapsing core and hurl the outer parts
into space. The inner core collapses a neutron star.
The result is a...
A Type II supernova to be precise.
The pictures, by David Malin, the Anglo Australian Observatory, show a region of the Large Magellanic Cloud before and after SN 1987A exploded on February 23, 1987. The star that exploded is indicated in the first image. Although it was 170,000 light years waway, it became easily visible to the naked eye. It was the closest and brightest Supernova as seen from the Earth in the past 350 years.