<p>Although you might think that Y-dwarfs (brown dwarfs with temperatures $&lt;500$ K) might become cool enough to support liquid water. In fact that does not happen. As discussed by <a href="https://arxiv.org/abs/astro-ph/0304226" rel="nofollow noreferrer">Burrows et al. (2003)</a> and <a href="https://arxiv.org/abs/1404.0005" rel="nofollow noreferrer">Morley et al. (2014)</a>, in Y-dwarf atmospheres, when the temperature becomes low enough for water to condense out of the gas phase ($&lt;375$K), it goes straight to water ice particles. </p>

<p>Thus, although water vapour <em>will</em> condense  in clouds in a cold brown dwarf, it will be in the form of ice particles, and there is not expected to be liquid water in a brown dwarf atmosphere.</p>

CC BY-SA 3.0
2017-03-14T23:08:06.890Z
2017-03-16T07:13:09.180Z
2017-03-16T07:13:09.180Z
ProfRob
<p>No. It would be really hard because although the coolest Brown dwarfs might be able to sustain water, they are made nearly completely of gas and that might by a problem. It would be very hard for water to exist on a brown dwarf, because if you were in the BD's "surface" the water would probably be in a gas phase due to the brown dwarf's low density there and pressure. But if it could exist as a pressurized water it probably still would be extremely hot, and unless the life form could survive that kind of temperatures it wouldn't exist.</p>

<p>Also, this is also very similar to life in gas giants. If it was to exist, it would need to be very small and not very dense. That way, it could still be part of the gases in the atmosphere and not sink.</p>

CC BY-SA 3.0
2017-03-14T22:43:17.570Z
Brown dwarfs have clouds.
ProfRob
CC BY-SA 3.0
2017-03-15T21:42:10.253Z
Okay, but should I include that in my answer?
StellarExile
CC BY-SA 3.0
2017-03-14T21:38:07.490Z
2017-03-14T21:38:07.490Z
StellarExile
<p>Some of brown dwarfs generate the enought amount of heat to warm their atmosphere up to 300 K. This is a condition to liquid water and, possibly, organic life forms.</p>

<p>Is where are a some studies about life forms in BD atmosphere?</p>

CC BY-SA 3.0
2016-08-08T15:10:19.173Z
There's a problem of density.  Liquid water is quite a bit denser than even very dense gas and to reach that density you'd have to be fairly deep inside the star, which would suggest much higher temperature.    It's like the submarine on Jupiter problem.   By the time density is equal to water, pressure and temperature are enormous.    https://what-if.xkcd.com/138/    Nice idea though, but liquid water is probably unlikely.   Also, see here:   http://www.nytimes.com/2002/08/06/science/forecast-for-brown-dwarf-stars-iron-rain-heavy-at-times.html
userLTK
CC BY-SA 3.0
2016-08-08T16:26:17.690Z
You should make that an answer, @userLTK.
pela
CC BY-SA 3.0
2016-08-08T18:54:19.283Z
Liquid water doesn't mean ocean. It could be a clouds... Microbes habitable clouds
Y.N
CC BY-SA 3.0
2016-08-08T20:00:03.893Z
I didn't mean to say it was impossible, only that liquid water is unlikely, but you're right, clouds with some liquid water is possible.
userLTK
CC BY-SA 3.0
2017-01-22T21:51:58.103Z
I think any answer to this would have to be speculation.
James K
CC BY-SA 3.0
2017-01-23T14:55:15.843Z
@JamesK An answer to "are there studies" would not be speculation. There either are or there aren't. It may be there aren't any since, as you said, it is a speculative topic.
called2voyage
CC BY-SA 3.0
2017-10-01T15:14:08.597Z
Not sure there'd be enough of an energy gradient for life to develop. AFAIK, brown dwarf atmospheres don't have many sharp changes in chemical or energy content of atmosphere. If you want life, you need some sort of flow be it chemical or energetic.
Wayfaring Stranger
<life><brown-dwarf>
Life forms in brown dwarf atmosphere
Y.N
# Life forms in brown dwarf atmosphere

(Asked by: username_0 on 2016-08-08)

Some of brown dwarfs generate the enought amount of heat to warm their atmosphere up to 300 K. This is a condition to liquid water and, possibly, organic life forms.

Is where are a some studies about life forms in BD atmosphere?

**Tags:** life, brown-dwarf
> **Comments:**
> **username_1**: There's a problem of density.  Liquid water is quite a bit denser than even very dense gas and to reach that density you'd have to be fairly deep inside the star, which would suggest much higher temperature.    It's like the submarine on Jupiter problem.   By the time density is equal to water, pressure and temperature are enormous.    https://what-if.xkcd.com/138/    Nice idea though, but liquid water is probably unlikely.   Also, see here:   http://www.nytimes.com/2002/08/06/science/forecast-for-brown-dwarf-stars-iron-rain-heavy-at-times.html  
> **username_2**: You should make that an answer, @userLTK.  
> **username_0**: Liquid water doesn't mean ocean. It could be a clouds... Microbes habitable clouds  
> **username_1**: I didn't mean to say it was impossible, only that liquid water is unlikely, but you're right, clouds with some liquid water is possible.  
> **username_3**: I think any answer to this would have to be speculation.  
> **username_4**: @JamesK An answer to "are there studies" would not be speculation. There either are or there aren't. It may be there aren't any since, as you said, it is a speculative topic.  
> **username_5**: Not sure there'd be enough of an energy gradient for life to develop. AFAIK, brown dwarf atmospheres don't have many sharp changes in chemical or energy content of atmosphere. If you want life, you need some sort of flow be it chemical or energetic.  

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## 2 answers

### Answer by username_6 on 2017-03-14. Score: 2

Although you might think that Y-dwarfs (brown dwarfs with temperatures $<500$ K) might become cool enough to support liquid water. In fact that does not happen. As discussed by [Burrows et al. (2003)](https://arxiv.org/abs/astro-ph/0304226) and [Morley et al. (2014)](https://arxiv.org/abs/1404.0005), in Y-dwarf atmospheres, when the temperature becomes low enough for water to condense out of the gas phase ($<375$K), it goes straight to water ice particles.

Thus, although water vapour *will* condense in clouds in a cold brown dwarf, it will be in the form of ice particles, and there is not expected to be liquid water in a brown dwarf atmosphere.


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### Answer by username_7 on 2017-03-14. Score: 0

No. It would be really hard because although the coolest Brown dwarfs might be able to sustain water, they are made nearly completely of gas and that might by a problem. It would be very hard for water to exist on a brown dwarf, because if you were in the BD's "surface" the water would probably be in a gas phase due to the brown dwarf's low density there and pressure. But if it could exist as a pressurized water it probably still would be extremely hot, and unless the life form could survive that kind of temperatures it wouldn't exist.

Also, this is also very similar to life in gas giants. If it was to exist, it would need to be very small and not very dense. That way, it could still be part of the gases in the atmosphere and not sink.

> **Comments:**
> **username_6**: Brown dwarfs have clouds.  
> **username_7**: Okay, but should I include that in my answer?  

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