Homework 2 Question 1
Xavier Wingfield
2/21/18
Phys390
Can Exoplanets be too Massive to Mind? :
A look at the limits of mass and what can be defined as a planet
Jupiter is not a little planet. At a size of 1.898X10^27 Kg and a radius of about 69,911 Km Jupiter is easily the biggest thing we have here in our solar system. But even with its tremendous size, it's still dwarfed by our sound by a factor of about 10 times. But that brings up an interesting question: What if it didn't? What if Jupiter suddenly grew by a factor of about 10, what happens then? Is it still considered a planet? Dr. Kevin C. Schlaufman does't think so. This all comes back to the question of what defines the word "planet", what is considered a planet? Originally it was known as a celestial body that moves around a star(1), but that definition might have changed. Dr. Schlaufman thinks the word planet should not be defined by its ability to orbit a star, but rather what kind of star it orbits if at all. Most planets that we know of that follow the precise definition of the word "planet" are almost all formed as a result of their parent star forming. As a star builds up speed giving a gravitational pull towards its core, the gravity this rotation makes creates an accretion disk which tell the large amounts of gas and particles where and on what plane to form. All the planets that then form because of the massive star's accretion are then locked into a steady orbit around said star thus making a solar system. But hold on, because if you step back to notice something, there was a key phrase that may prove useful in this situation; Gravitational pull. A star is able to become a star due to a massive cloud of gas and dust given an initial velocity and this eventually causes the dust to condense to a point, but look at how much dust made that star. The planets that orbit a star, come from the leftover remains of the star that initially spawned them meaning there should be no reason a planet that orbits a star would be bigger than the star it originally was given life by. Our sun holds within it 99.8% of all the mass in our solar system meaning everything else makes up a very measly 0.2%. Remember, that the massive object of Jupiter resides within that tiny 0.2%. So How does a planet the size of a star come from a star? It's simple: it probably didn't. Dr. Schlaufman calculated that an object with less than 10 times the mass of Jupiter could orbit a metal-rich solar-type dwarf star, though a celestial object more that this wouldn't as the object is large enough to be a star itself. It was calculated that objects don't orbit metal-rich solar-type dwarf stars once they reach a certain size. Roughly between 4 times and 10 times the size of Jupiter, exoplanets are found orbiting stars much like our own, but anything more than 10 times the mass of Jupiter either don't actually orbit a star, or don't orbit a metal-rich one. To prevent planets from being this large, protoplanetary disks are far smaller or far less massive to prevent not only damage to itself and the surrounding planets, but to the star forming it as well. If the planet were to get too large, the star forming it would take longer to move our of the Type I/II planetary embryonic stage which then would begin to affect the survival of that star's gravitational stability which in turn would disrupt the newly forming star's mass, plant formation location and even characteristic disk dissipation time. If this were to happen, there would be a good chance the star wouldn't fully finish its development and has the possibility of a lot of disastrous results and that's only if the star finishes forming at all.
Xavier Wingfield
2/21/18
Phys390
Can Exoplanets be too Massive to Mind? :
A look at the limits of mass and what can be defined as a planet
Jupiter is not a little planet. At a size of 1.898X10^27 Kg and a radius of about 69,911 Km Jupiter is easily the biggest thing we have here in our solar system. But even with its tremendous size, it's still dwarfed by our sound by a factor of about 10 times. But that brings up an interesting question: What if it didn't? What if Jupiter suddenly grew by a factor of about 10, what happens then? Is it still considered a planet? Dr. Kevin C. Schlaufman does't think so. This all comes back to the question of what defines the word "planet", what is considered a planet? Originally it was known as a celestial body that moves around a star(1), but that definition might have changed. Dr. Schlaufman thinks the word planet should not be defined by its ability to orbit a star, but rather what kind of star it orbits if at all. Most planets that we know of that follow the precise definition of the word "planet" are almost all formed as a result of their parent star forming. As a star builds up speed giving a gravitational pull towards its core, the gravity this rotation makes creates an accretion disk which tell the large amounts of gas and particles where and on what plane to form. All the planets that then form because of the massive star's accretion are then locked into a steady orbit around said star thus making a solar system. But hold on, because if you step back to notice something, there was a key phrase that may prove useful in this situation; Gravitational pull. A star is able to become a star due to a massive cloud of gas and dust given an initial velocity and this eventually causes the dust to condense to a point, but look at how much dust made that star. The planets that orbit a star, come from the leftover remains of the star that initially spawned them meaning there should be no reason a planet that orbits a star would be bigger than the star it originally was given life by. Our sun holds within it 99.8% of all the mass in our solar system meaning everything else makes up a very measly 0.2%. Remember, that the massive object of Jupiter resides within that tiny 0.2%. So How does a planet the size of a star come from a star? It's simple: it probably didn't. Dr. Schlaufman calculated that an object with less than 10 times the mass of Jupiter could orbit a metal-rich solar-type dwarf star, though a celestial object more that this wouldn't as the object is large enough to be a star itself. It was calculated that objects don't orbit metal-rich solar-type dwarf stars once they reach a certain size. Roughly between 4 times and 10 times the size of Jupiter, exoplanets are found orbiting stars much like our own, but anything more than 10 times the mass of Jupiter either don't actually orbit a star, or don't orbit a metal-rich one. To prevent planets from being this large, protoplanetary disks are far smaller or far less massive to prevent not only damage to itself and the surrounding planets, but to the star forming it as well. If the planet were to get too large, the star forming it would take longer to move our of the Type I/II planetary embryonic stage which then would begin to affect the survival of that star's gravitational stability which in turn would disrupt the newly forming star's mass, plant formation location and even characteristic disk dissipation time. If this were to happen, there would be a good chance the star wouldn't fully finish its development and has the possibility of a lot of disastrous results and that's only if the star finishes forming at all.
This was a great summary and overwhelmingly informative. I appreciate the help in understanding.
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