Black Hole Question...?

Question

Is it possible for a planet to have greater mass than a star? If so, wouldnt a star orbit this planet? Would this planet be visible through a telelscope? Do you see where I'm going? Thanks...

Answer 1

As many of the previous answerers have written, once a planet reaches a certain critical mass, in would most likely implode due to the tremendous gravitational forces and a star would be born. Small dwarf stars as also previously been mentioned are usually not the original state of the star but what is left over after it has gone through a nova (i.e. blown off most of it's outer shell into space). Of course, if there was any massive planet in its orbit, it would probably have been annihilated by the blast.

In any case, no matter how massive the planet is, it cannot be directly seen due to the fact that is a dark object (i.e. not emanating light or radiation). The only reason we see stars in the sky is due to their enormous output of light. Neutron stars and other less luminous objects are detected by their radiation output or gravitational effects on neighboring visible stars, not because they themselves are visible through a telescope. A planet would just be another invisible black dot in an infinite black field.

Answer 2

In all circumstances, the 'planet' would be a gas giant. Planets about 5 times bigger than Jupiter can achieve nuclear fusion. Yet even a planet 5 times bigger than Jupiter would only be about a quarter the size of the star it orbits. The important fact that I pondered here is that a planet can only be so large, until it reaches a critical state where fusion begins. I wonder how big that is?

The planet would only be visible if it had achieved fusion. It would then be classified as a binary anyways. The twin in a binary CAN be sucked into a black hole.

Last note, I don't believe that a rocky planet can get any bigger than a certain critical size also, because even gas giants are rocky planets at the core. They just gather more and more matter and comets and gas until they have a huge atmosphere, and are classed gas giants.

Answer 3

Yes, a neutron star usually has a diameter of a few kilometers, smaller than most planets. It wouldn't be orbiting any planets though. If the star (before it became a neutron star) had planets orbiting it, then the planet would either be destroyed by the supernova or drift into space. I don't think conservation of momentum would allow the planet to stop all of a sudden and then have the star orbit it.

Then again a neutron star is so dense and massive that if you could bring back a spoonful of it to Earth it would weigh thousands of tons....
So it is still massive enough and have a strong gravity to have a much larger planet orbiting it.

Answer 4

No, it is not possible. Even the smallest star is massive enough to sustain nuclear fusion in its core. For that you need to have a body with a mass of at least about one tenth the mass of the Sun. If a "planet" has a mass beyond that, it is a "star".

However, you might have a low-mass red dwarf star and a large brown dwarf (which is not a star, but an intermediary between a gas giant planet and a red dwarf) circling together and having very similar masses. The red dwarf would still be more massive, though.

Answer 5

Scientists have observed massive planets in stellar systems other than our own. Generally, these planets can be are so massive that the star and the planet orbit around a mutual barycentre, in a sort of binary system like fashion. However, none of these planets have a mass greater than the mass of the star.

Answer 6

a star is the focal point of gravity in a system... sometimes there are two stars clled a binary system, and both make up the largest part of gravity pull in a system. This causes things to orbit around them. So a star would be the thing that causes others to orbit around it.
The other part about visible is not "clear". Scientists use other frequencies to determine " If things are there" and also the can see it moving in an irreguar pattern. The cause for the irregular pattern is assumed to be because of some other massive object.

But in conclusion. the object doesnt have to be in line of sight to be seen, just its effects on its neighbors must be seen.

Answer 7

well,i've been in love with astronomy for quite a while,so,i'll try to answer ur question.
i don't think it's possible 4 a planet to have greater mass than a star.if it does,it probably will be a star itself.did u know that astronomers call Jupiter, 'a failed star'?Jupiter needs a little more mass so that the nuclear inside can be strong enough for Jupiter to emit its own light.but it doesn't have enough mass to be a star,that's why astronomers call it 'a failed star' coz it just needs a bit more to become a star.but i don't think we want that,do we?two stars in one solar system?it's hot enough as it is.

oh,right,did u know there's a supermassive black hole at the center of every galaxy? :)

Answer 8

Yes theres planets out there with more mass then some stars, and yes it should be visible through a telescope if that telescope can view that far to see a planet with more mass then a star.

Answer 9

If a planet had that much mass it would have enough gravity to become a star.

Answer 10

A large celestial body with a small one in orbit around it is technically in orbit around the smaller body also.
The planet may change Doppler shift and brightness that may betray its presence.