Supernovae

The purpose of this thread is to discuss anything related to related to supernovae.Some of the interesting topics in my opinion are:1) Discussing my views of SN(e)1987A which can be found here:
http://www.geocities.com/peaceharris/sn1987a/2) The distance of SN1993J3) Justification of using type 1A supernovae as standard candles.4) Is the crab nebula really a SN remnant?Feel free to discuss whatever else related to SNe.

As far as I know, all supernovae that have been observed in the past century, after peaking in its luminosity, gradually went dimmer. Thus the view that a supernova explosion indicates the death of a star is quite justified. For example, sn1987a, which in 1987 was brightest object in the LMC, is now hardly visible even with the most powerful telescopes.However, the object which illuminates the crab nebula is a very powerful source, inspite of being 1000 years old. It is commonly believed that this object was first seen by Chinese astronomers 1000 years ago. My contention is that the Chinese witnessed a star birth, and not a star death.According to biblical chronology, stars were created on the 4th day, 6000 years ago. If the literal interpretation of the bible is correct, a star birth event observed 1000 years ago would imply that the star is 5000 light years away.Let me quote from
http://hcs.harvard.edu/~jus/0302/bester.pdf"To summarize, our best estimate of the distance to the Crab Nebula is 5,600 light years, although we can say with certainty only that it lies between 4,000 and 7,000 light years."

I do not think that the crab pulsar is a rotating neutron star. Why should a rotating neutron star produce a magnetic field?However, a rotating normal non-degenerate star can produce a magnetic field. Due to high temperatures, we would expect ionized atoms. The rotating ionized atoms are like a huge electrical current. From Ampere's law, an electric current produces a magnetic field.Rotating neutrons which are electrically neutral, shouldn't create a magnetic field.Added in edit:
Does the fact that it isn't very powerful in the visible imply that it is a neutron star? For example, Sirius B is very powerful in the x-ray region, but it is not a neutron star. APOD: 2000 October 6 - X-Rays From Sirius B This message has been edited by peaceharris, 04-02-2005 11:07 AM

About points 2 and 3: I do not know how astronomers have come to their conclusions. The reason why I suggested these topics is merely to get find out the basis of their conclusions.About the crab pulsar: We have observed sufficiently many SNe in the past century to convince us that pulsars are not from SN remnants.

Eta wrote, "A neutron star is not just neutrons... "I did a google search, and found this document:
http://www.nd.edu/~jina2/docs/events/phila/FWeber.pdfAccording to that document in the 1930's, people believed that neutron stars consisted of just neutrons. But the view in 2004 is that there is a layer of superconducting protons in the core.