## Rogue 'planet' discovered

Discuss the Traveller RPG and its many settings
phavoc
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### Rogue 'planet' discovered

It's 12x bigger than Jupiter, maybe even a failed brown dwarf. So planet might be a little off...

https://nypost.com/2018/08/06/huge-glow ... ugh-space/
Rikki Tikki Traveller
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### Re: Rogue 'planet' discovered

It was previously classified as a Brown Dwarf, but they now think it is younger than originally estimated, which makes it lower mass and thus a planet, not a star.
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Pyromancer
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### Re: Rogue 'planet' discovered

First I thought about Blindsight (the novel by Peter Watts), but then I read 20 lightyears...
Tom Kalbfus
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### Re: Rogue 'planet' discovered

phavoc wrote:
Mon Aug 06, 2018 4:12 pm
It's 12x bigger than Jupiter, maybe even a failed brown dwarf. So planet might be a little off...

https://nypost.com/2018/08/06/huge-glow ... ugh-space/
You mean 12 times the mass or 12 times Jupiter's diameter? Jupiter has a diameter of 142,984 km in which case it would have a diameter of 1,715,808 km, the sun has a diameter of 1,392,000 km, so I kind of doubt that a planet could be this big, so the must mean mass. Jupiter has a gravity of 2.5g, so 12 times that is 30g if the planet is the same size as Jupiter, the square root of 30 is 5.48, which is the number of Jupiter radii at which the gravity would be 1-g. This would be a radius of 391,578 km, Jupiter's radius is
71,492 km at the equator. One can build a double-sided orbital ring around this planet at 391,578 km, it would take the inner ring 7.8 hours to make a complete rotation to produce 1-g on its inner surface, the outer ring would not rotate at all and its gravity would be 1-g pulling inward. If both rings were 12,800 km wide, their surface area would be 61.18 Earths each for a total of 122.36 Earths of surface area. If they do a new edition of the 2300 game, they might want to include something like this. 20 light years is within the 50 light year near star map.
steve98052
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### Re: Rogue 'planet' discovered

This article says that it's 12.7 times the mass of Jupiter and 1.2 times diameter of Jupiter. With 1.2 times the diameter, it is 1.7 times the volume of Jupiter, so it is around 7.3 times the density of Jupiter.

http://www.astronomy.com/news/2018/08/free-range-planet
Linwood
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### Re: Rogue 'planet' discovered

High density feels like it fits with high magnetism. So - high metallic content?
Tom Kalbfus
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### Re: Rogue 'planet' discovered

Linwood wrote:
Tue Aug 07, 2018 10:19 am
High density feels like it fits with high magnetism. So - high metallic content?
Not necessarily, hydrogen compresses a lot when under pressure. The gravity on this planet's surface would be greater than on our Sun. A lot of mass in a small place has some uses in world building. This planet radiates heat, which means it has a habitable zone just like a star, except it is much closer to its surface. We can build a shell world around it.
Pyromancer
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### Re: Rogue 'planet' discovered

Tom Kalbfus wrote:
Tue Aug 07, 2018 1:45 pm
Linwood wrote:
Tue Aug 07, 2018 10:19 am
High density feels like it fits with high magnetism. So - high metallic content?
Not necessarily, hydrogen compresses a lot when under pressure.
And then it becomes metallic. There's a theory that the core of Jupiter consists of metallic hydrogen.
Tom Kalbfus
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### Re: Rogue 'planet' discovered

Pyromancer wrote:
Tue Aug 07, 2018 2:56 pm
Tom Kalbfus wrote:
Tue Aug 07, 2018 1:45 pm
Linwood wrote:
Tue Aug 07, 2018 10:19 am
High density feels like it fits with high magnetism. So - high metallic content?
Not necessarily, hydrogen compresses a lot when under pressure.
And then it becomes metallic. There's a theory that the core of Jupiter consists of metallic hydrogen.
So it would have a larger metallic hydrogen core than Jupiter, this planet is right on the edge of being a brown dwarf, where deuterium fuses but not plain hydrogen.

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