<p>Brown dwarfs are heavier than Jupiter (jupiter has mass 0.000949 solar masses), although about the same size. Their compositions are fairly similar, with brown dwarfs <a href="https://arxiv.org/abs/1008.5150" rel="nofollow noreferrer">depleted in deuterium if they are heavy enough</a> (it is burned over a few million years after formation). </p>

<p><a href="https://arxiv.org/abs/astro-ph/9701131" rel="nofollow noreferrer">Adams &amp; Laughlin</a> modelled the collisions of brown dwarfs, mainly to estimate whether two dwarfs could merge to make a star heavier than 0.075 solar masses that would begin hydrogen fusion properly. They found that this could happen, and not too much mass appears lost as they splatter into each other if it is a somewhat glancing collision. Obviously, a near glancing hit might just scatter some of their atmospheres but not stop them. </p>

<p>Jupiter would likely behave the same. The result would be a heavier brown dwarf. It would be heated significantly by the energy of the merger, which in turn would make it expand to a larger size until it cooled down. Jupiter would also contribute deuterium so if the dwarf was heavy enough it would further heat up for a while. Given Jupiter's minimal mass compared to the 0.075 limit it is not likely it would be enough to turn the new object into a red dwarf.</p>

CC BY-SA 3.0
2018-02-06T20:00:06.657Z
2018-02-06T20:00:06.657Z
Anders Sandberg
<p>What would happen to Jupiter if a brown dwarf star collided with it, and vice versa what would happen to the brown dwarf star?</p>

CC BY-SA 3.0
2018-02-05T17:29:37.237Z
A brown dwarf is a minimum of 13 Jupiter masses.  Any collision would wipe out Jupiter.  I doubt we could say what would happen a brown dwarf and it would be very dependent on the details anyway.
StephenG - Help Ukraine
CC BY-SA 3.0
2018-02-05T18:22:51.770Z
Regarding the close vote, the question is pretty clear. OP just seems to misunderstand the shear size ratio between Jupiter and a brown dwarf.
Sir Cumference
CC BY-SA 3.0
2018-02-05T19:19:21.053Z
I've removed the first paragraph. OP.  Please [edit] to tell us about some of your previous research, such as finding out what a "brown dwarf" is
James K
<star><the-sun><planet><jupiter><brown-dwarf>
Jupiter vs brown dwarf star
David Jones
# Jupiter vs brown dwarf star

(Asked by: username_0 on 2018-02-05)

What would happen to Jupiter if a brown dwarf star collided with it, and vice versa what would happen to the brown dwarf star?

**Tags:** star, the-sun, planet, jupiter, brown-dwarf
> **Comments:**
> **username_1**: A brown dwarf is a minimum of 13 Jupiter masses.  Any collision would wipe out Jupiter.  I doubt we could say what would happen a brown dwarf and it would be very dependent on the details anyway.  
> **username_2**: Regarding the close vote, the question is pretty clear. OP just seems to misunderstand the shear size ratio between Jupiter and a brown dwarf.  
> **username_3**: I've removed the first paragraph. OP.  Please [edit] to tell us about some of your previous research, such as finding out what a "brown dwarf" is  

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## 1 answers

### Answer by username_4 on 2018-02-06. Score: 4

Brown dwarfs are heavier than Jupiter (jupiter has mass 0.000949 solar masses), although about the same size. Their compositions are fairly similar, with brown dwarfs [depleted in deuterium if they are heavy enough](https://arxiv.org/abs/1008.5150) (it is burned over a few million years after formation).

[Adams & Laughlin](https://arxiv.org/abs/astro-ph/9701131) modelled the collisions of brown dwarfs, mainly to estimate whether two dwarfs could merge to make a star heavier than 0.075 solar masses that would begin hydrogen fusion properly. They found that this could happen, and not too much mass appears lost as they splatter into each other if it is a somewhat glancing collision. Obviously, a near glancing hit might just scatter some of their atmospheres but not stop them.

Jupiter would likely behave the same. The result would be a heavier brown dwarf. It would be heated significantly by the energy of the merger, which in turn would make it expand to a larger size until it cooled down. Jupiter would also contribute deuterium so if the dwarf was heavy enough it would further heat up for a while. Given Jupiter's minimal mass compared to the 0.075 limit it is not likely it would be enough to turn the new object into a red dwarf.


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