Jupiter, the star that failed,...BUT does it still have a chance??

Question

I recently read a book, titled, "Jupiter, The Star That Failed" by
Joel N. Shurkin. In the book, I believe the author stated that Jupiter would need about 100 times its current mass to have enough gravity to create the internal pressure which would cause the temperature to rise to the 20 million degrees necessary for fusion to begin. And thus shine like a star. The cube root of 100 times its current diameter is 4.64*88,865 = 412,000 miles. This is very rough I know but my question are:

1. Can Jupiter continue to accumulate hydrogen over a few million years and eventually reach this point??

2. Can the process described above be considered the way stars do come to be?? In other words can Jupiter be considered to be a "pre-star"?

3. Why aren't all stars the same size? Seems they would all hit the mass requirement for fusion & be the same size?

4. Can stars grow after fusion begins?

or this 5. Good beginners book on star formation?

Answer 1

Sorry, Jupiter does not have the chance... Or only in the Stanley Kubrick's movie.
The Sun is a small star, but has 1000 times the Jupiter mass. To be a brown dwarf star, Jupiter would need 100 times its mass.
1] When the Solar System was young, the hydrogen and other elements were available to grow. Now the space is almost empty.
2] Actually Jupiter radiates more energy than the one received from the Sun, so it is possible that some (but very little) fusion occurs. Jupiter could be considered as a quasi-star, but this condition is forever.
3] The stars come from gas clouds. If the cloud were larger, the star would be larger, or more stars would be born (multiple systems)
4] As the gas cloud collapses, the temperature increases, due to the pressure and to the fusion. The equilibrium stabilizes the size, the temperature, the fusion rate, and the pressure. After some billion years, the star don't have the hydrogen required for the equilibrium, and a new equilibrium must start with the helium as a fuel
5] ► http://en.wikipedia.org & search 'star', 'fusion', 'galaxy', 'universe', 'hydrogen', 'jupiter', 'Sun' etc. More information in the source

Answer 2

First, Jupiter is not a failed star. It is not even a brown dwarf. Jupiter is a planet in the gas giant category.

1 No. There isn´t enough hydrogen (or matter for that matter) left in the solarsystem to increase Jupiters mass 70 times (not 100 times as the author propose) to make it fuse hydrogen. In fact the combined mass of all the other planets in the solars system wouldn´t even make a second Jupiter...

2 Well stars do form through the accretion of mass and double starsystems is a common configuration. But no. Jupiter is not a pre-star. It is a planet.

3 Stars form out of swirling clouds of gas and dust. Look at the sky. Ever seen two clouds of exactly the same size? All clouds are different in size and mass (and in space in composition) and so pretty much all stars are slightly different. But there is an upper limit to how massive a star can get, though, were fusion becomes so intense it immediatley blows its outer layers off. That limit is about 100 solarmasses.

4 I suppose they could. The first blastwave of a new star would whisk away alot of matter towards the edge of the solarsystem but some would keep on falling into the star (and some would form planets). Even today comets on occasion can be seen crashing into the sun so the sun could be said to be growing (but actually the sun looses way more mass, by converting it to energy, every second than comets can ever increase its mass with).

5 "Stars" by JP Kaler.

Oh and its a Peter Hyams movie. Not a Stanley Kubrick movie... (2010)

Answer 3

All the hydrogen in the vicinity of our solar system has either gone into making the sun and planets or been blown away by the solar wind, so there is no free hydrogen left for Jupiter to accumulate. Jupiter would need to be about 12 times more massive just to make it to brown dwarf. Even if it somehow managed to ingest the other gas giants, there isn't enough mass there.

The size of a star depends on the mass and density of the cloud it condensed from. In larger stars matter continues to fall into the star even after the core has ignited. These clouds are opaque, so it takes some time for the energy from the core to escape. So I think there is a lag between the beginning of fusion and the development of a stellar wind that will eventually blow away the surrounding cloud. Stars in binary or multiple star systems may accumulate material late in life from a companion that has swollen up into a red giant. Perhaps when our sun reaches its giant phase, Jupiter will be able to pick up material from the sun.

I don't know of a book on star formation specifically, but I like "Stars and Their Spectra" by James Kaler as a good general introduction to stars.

Answer 4

1. No
2. No
3. A large nebula (one with a large amount of mass) will form a large star, and a small nebula will form a small star. However, in addition to a star's initial mass, a star's size also depends on the balance between the inward pull of gravity and the outward push of the energy produced by fusion. The entire sequence of a star's evolution can be described in terms of the changing balance between these two opposing forces.
4. No
5. Considering how many incorrect views formed the above questions, my answer here is also No.

Answer 5

Jupiter did come close to being a small star, but it did not, nor will it ever become one. Stars begin to lose mass after they begin fusing hydrogen into helium. Stars are born from differing sizes of clouds of hydrogen, the larger the cloud the larger the star.