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I saw a similar "ufo" several decades ago, before there were Iridium satellites. Possibly it was another type of satellite with large reflective panels. Thinking it over, I later decided that if an airplane reflected the sunlight directly toward me at one moment of a turn, it might make a similar flash.


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Is it incorrect to call the explosion “supernova”? Yes and no. Better said, the explosion is the very first part of a supernova. While the explosion lasts for but a few seconds to a few hundreds of seconds, a supernova can last for hundreds of days. What we see visibly as a supernova are the after effects of that explosion. The explosion can create ...


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A supernova is the explosion, visible on Earth as a apparently new star that appears to brighten over a few days, and then fade. There have been no visible supernovae in our galaxy for several hundred years, and we are well overdue another one, though they are quite often visible in other galaxies. After the supernova there will be a remnant, a small nebula ...


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In a white dwarf, the dense matter is not in its lowest energy configuration. Energy can still be extracted from the white dwarf material by fusion, provided it can be ignited. What exothermic nuclear reactions would there be that could take place in a neutron star? The bulk of the material is in the form of neutrons with a small number of protons and ...


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Whether a white dwarf responds to the accretion of material by exploding or collapsing depends on the competition between energy being released in fusion reactions and energy being locked away by endothermic electron capture (neutronisation) reactions. It is thought that most white dwarfs of moderate mass have a C/O composition. They will need to accrete a ...


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There are a variety of white dwarfs with various compositions, and analysing how they detonate in a supernova (or not) is an topic under investigation. A simple model, described in "How is the first detonation in Supernove type Ia triggered?" is of a helium shell initially igniting and that setting off the carbon in the core. In this type of Type 1a ...



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