SUPERNOVA 1998S

On March 3, Chinese astronomers noted a bright star in the galaxy NGC 3877 that was not there the last time anyone had looked.

The star is "bright" only in relative terms as it takes a respectable telescope to even see it. However, as the galaxy is so far away that no other star in it can ever be seen with any telescope, just seeing it is big news.

What's a supernova?

A supernova is a star that explodes in such a violent manner that the energy produced can exceed the entire energy output of all the billions of stars in the galaxy where it resides. A normal star (like the Sun) "burns" hydrogen in its nuclear furnace at a controlled rate that will keep it burning for billions of years. A supernova burns about half it's total mass in a period of weeks and if we remember Einstein's famous equation: e = mc squared, we must multiply half of the stars mass times 186000 x 186000 to get the amount of energy produced. A monster explosion indeed.

I said the event "took place" this year but actually it happened millions of years ago and even traveling at the speed of light (186,000 miles per second) we didn't know it happened until the light got here and that was in March of this year.

Although supernovae are the biggest things that can happen in the universe since the Big Bang, they are not all that rare on the cosmic scale. Any given galaxy might have a couple every thousand years or so and as there are millions of galaxies within reach of our telescopes, we can see several each year.

The good news is that there has never been one anywhere near our location in our galaxy (the Milky Way) and we are therefore still around to marvel at them. Although 4 have been witnessed and recorded in the past thousand years, not a single one has appeared in our galaxy since the invention of the telescope.

To see an example of a recent near miss go to: Crab Supernova Remnant

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