- #1
Stephanus
- 1,316
- 104
"When a massive star develops an iron core larger than the Chandrasekhar mass..."
http://en.wikipedia.org/wiki/Supernova
Dear PF forum.
Folks, what I have here may be an unimportant question. Still I'm curious to know the answer.
When iron fusion happens in a massive star, it will undergo supernova.
What I want to know is...
1. There are some binary (or perhaps ternary) neutron star systems.
Neturon star is the product of a supernova (the other product may be a black hole). If the star explodes, will it scatter its solar system (or simply "its system," "SOL" is the name of our sun) away?
Why does it still have companion?
2. During a supernova explosion, can the star be ejected through its trajectory orbit with respect to the center of the galaxy?
I'm not trying to throw a Fermi Problem here, but...
If there are approximately 100 billions of stars in a galaxy, take Milky Way for an example.
And the rate of star born is -- 13.5 billions years (age of the universe) / 100 billions (stars in Milky Way) ≈ 1 star per month is born.
And 10% of those stars can undergo supernova according to its mass (our star can't and its just an average star).
And the lifespans of a massive star is perhaps 30 millions years. But 30 millions years should'nt be in the equation, right?.
Thus, we have only 1 month / 10% ≈ 1 year. So, every year a supernova explodes in our Milky Way. Up until now, there should be 13.5 billion supernovas in our galaxy alone. Let's say my approximation is incorrect. Let's say it's only 1 billion supernovas. And.. about 1% of them if question number 2 is correct is a rogue neutron star. So that would be... 10 millions rogue neutron stars or black holes in our galaxy alone!
Is that correct?
Other calculation
Our Milky way is 80 000 ly by 1000 ly thick. So... In a cylinder of 40000 x 40000 x 1000 x π = 5 trillion ly cube. (calculator here...)
So in a cyllinder of 5 trillion ly cube there are 10 million of these rogue stars. Or 1 star in every 500 000 ly cube.
It's "only" a cube of 80 ly length. And our nearest star is 4.3 ly away. So our Milky Way are actualy roamed by these rogue stars.
Again, if this is correct, and it's just an idea.
But, what I really want to know is, how is the chance of a supernova causing the star to deviate from its trajectory orbit to the center of the galaxy and if somehow our star (which can't) undergoes a supernova, will it scatter Jupiter or Neptune away?.
Thanks for the answer.Steven