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61 Supernova Remnants
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A Supernova remnant (SNR) is an expanding cloud of dust and gas,. Such an SNR should be perceivable for more than a million years before it disintegrates. However, the number of Supernovae in our Milky Way is considerably lower than expected . The number of SNR agrees with a Milky Way which is approx. 7,000 years old.
When a star with approx. 25 times the mass of our sun has burned a sufficient quantity of hydrogen to helium, it explodes. This temporary gigantic release of energy leads to an extraordinarily bright light within the course of a few days of weeks which can outshine all the other stars in the same galaxy. Such an event is called a Supernova.
A Supernova can release the amount of energy which would normally be radiated by 1,000 suns over a period of 8 million years (1). It leaves a gigantic cloud of gas, the Supernova remnant (SNR) and a small central star. The SNR continuous to expand following the explosion at a rate of over 7,000 km/sec and can reach a diameter of several light years in the course of time.
The SNR expansion process is described in three stages:
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| 1. |
During the first 300 years, the SNR expands to a diameter of approx. 23 light years. The gaseous SNR then changes slowly into a liquid state.
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| 2. |
During the next 120,000 years, the SNR should continue to expand to a diameter of approx. 350 light years. During this process, the now liquid droplets slowly form solid dust.
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| 3. |
During the next 6 million years, the SNR would then thin out as a result of the expansion so that it finaly could no longer be distinguished from its surrounding .
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Approx. every 25 years we can observe a Supernova in our Milky Way. Depending on its position in the galaxy, the light from the SNR is weakend more or less by interstellar dust so that some of them are not visible any more.
Calculations and observations (1):
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| First stage SNR: |
According to calculations, 19% of 12 first stage SNR’s should be visible; 2 have been observed.
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| Second stage SNR: |
According to calculations, 47 % of 4,800 second stage SNR’s should be visible. However, only 200 have been observed. This is the number we could expect after approx. 7,000 years.
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| Third stage SNR: |
According to calculations, 14% of 40,000 third stage SNR’s should be visible. However, none whatsoever have been observed.
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Crab Nebula:
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When the first photographs of the Crab Nebula were made in the beginning of the 20th Century, it was noted that the nebula was expanding. Calculating back using this expansion rate it was possible to conclude a Supernova explosion at 900 years ago. As a matter of fact, a Supernova did occur in 1054 which was observed and is documented in 13 independent historical sources (2).
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Swan Nebula (Cygnus):
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Calculations performed some time ago indicated that the Swan Nebula is 100,000 years old. However, new data indicates that this figure should be reduced to less than 3,000 years. One of the variables on which the expansion rate of a nebula depends is the density of the interstellar medium. In the vicinity of the Swann Nebula, this density is approx. 10 times lower than the standard density in space. For this reason, new calculations revealed that the Swann Nebula has expanded to the size observed today in less than 3,000 years (3).
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References:
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| (1) |
Keith Davies, Distribution of Supernova Remnants in the Galaxy, Proceedings of the Third International Conference on Creationism, Pittsburgh 2, Penn., USA, 1994, P. 177. |
| (2) |
Jonathan Sarfati, Exploding stars point to a young universe, Creation ex nihilo, Vol. 19, No. 3, June-August 1997, P. 46–48. |
| (3) |
Keith Davies, The Cygnus Loop – a case study, Journal of Creation, 20(3) 2006, P. 92–94. | |
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