<p>The creator seems to be referring to <a href="https://en.wikipedia.org/wiki/Flare_star" rel="nofollow">flare stars</a>. Flares may be magnetic in origin, like various manifestations of the Sun's magnetic field. These flares can be quit luminous across the electromagnetic spectrum, including in the x-ray wavelengths.</p>

<p>Some red dwarfs are flare stars, though flare activity may be largely restricted to a small part of a red dwarf's lifetime. However, during this period, life on a planet orbiting close to a red dwarf could be in serious danger.</p>

<p>The reference to convection may be that <a href="http://arxiv.org/abs/0901.1659" rel="nofollow">red dwarfs are generally fully convective</a>, unlike other stars. Magnetic fields in stars are generated via <a href="https://en.wikipedia.org/wiki/Dynamo_theory" rel="nofollow">the dynamo effect</a>; in red dwarfs, full convectivity can play a huge role in generating strong magnetic fields, and thus stellar flares.</p>

CC BY-SA 3.0
2016-02-03T16:56:49.123Z
2016-02-03T21:18:30.053Z
2016-02-03T21:18:30.053Z
HDE 226868
<p>I recently saw this <a href="https://www.youtube.com/watch?v=LS-VPyLaJFM&amp;feature=youtu.be" rel="nofollow">video</a>. The creator of the video says that one of the reasons for non-existence of life on planets around red dwarfs might be that these stars can increase <strong>luminosity roughly by a factor of 2</strong> in a matter of seconds which will boil off water from planets. He also said something about Helium/Hydrogen convection belts which are responsible for this. Can someone please explain this phenomenon? </p>

CC BY-SA 3.0
2016-02-03T13:14:11.410Z
http://youtu.be/jfvMtCHv1q4
Jaywalker
CC BY-SA 3.0
2016-02-03T13:14:30.770Z
This explains the convectional properties
Jaywalker
CC BY-SA 3.0
2016-02-04T03:05:44.957Z
Your question is more on the mechanism, but I think, with a thick enough atmosphere a heating up by double wouldn't be a deal breaker.   Or, a water world, the surface could evaporate but just a few feet under the surface, the temperature wouldn't change much.   A tidally locked planet with life on the ring, they could probably endure a flare-up.  This site says they last 10 days or so.   http://www.mssl.ucl.ac.uk/www_solar/PUS/PO/explosions.html  I don't think they're ideal but I don't think life is "impossible" either.  Life is good at adapting.   Life could dig underground for example.
userLTK
<life><luminosity><red-dwarf>
Red dwarf variation in Luminosity
Knu8
# Red dwarf variation in Luminosity

(Asked by: username_0 on 2016-02-03)

I recently saw this [video](https://www.youtube.com/watch?v=LS-VPyLaJFM&feature=youtu.be). The creator of the video says that one of the reasons for non-existence of life on planets around red dwarfs might be that these stars can increase **luminosity roughly by a factor of 2** in a matter of seconds which will boil off water from planets. He also said something about Helium/Hydrogen convection belts which are responsible for this. Can someone please explain this phenomenon?

**Tags:** life, luminosity, red-dwarf
> **Comments:**
> **username_1**: http://youtu.be/jfvMtCHv1q4  
> **username_1**: This explains the convectional properties  
> **username_2**: Your question is more on the mechanism, but I think, with a thick enough atmosphere a heating up by double wouldn't be a deal breaker.   Or, a water world, the surface could evaporate but just a few feet under the surface, the temperature wouldn't change much.   A tidally locked planet with life on the ring, they could probably endure a flare-up.  This site says they last 10 days or so.   http://www.mssl.ucl.ac.uk/www_solar/PUS/PO/explosions.html  I don't think they're ideal but I don't think life is "impossible" either.  Life is good at adapting.   Life could dig underground for example.  

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## 1 answers

### Answer by username_3 on 2016-02-03. Score: 4 | Accepted answer

The creator seems to be referring to [flare stars](https://en.wikipedia.org/wiki/Flare_star). Flares may be magnetic in origin, like various manifestations of the Sun's magnetic field. These flares can be quit luminous across the electromagnetic spectrum, including in the x-ray wavelengths.

Some red dwarfs are flare stars, though flare activity may be largely restricted to a small part of a red dwarf's lifetime. However, during this period, life on a planet orbiting close to a red dwarf could be in serious danger.

The reference to convection may be that [red dwarfs are generally fully convective](http://arxiv.org/abs/0901.1659), unlike other stars. Magnetic fields in stars are generated via [the dynamo effect](https://en.wikipedia.org/wiki/Dynamo_theory); in red dwarfs, full convectivity can play a huge role in generating strong magnetic fields, and thus stellar flares.


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