<p>Pulsars emit large amounts of ionizing radiation. It has a very powerful magnetic field which causes it to 'release' jets of electron-positron pairs. Atmosphere in the pulsar planets escapes off due to the intense heating effect of the X-Rays. If a planet has a suitable magnetic field then it can minimize the effect of irradiation. Atmosphere of an earth-like planet will be stripped away in a relatively short time. Earth-like atmosphere with earth-like magnetosphere will not survive for long. This is short period of time insufficient for complex life-forms to evolve.</p>
<p>The habitable zone for a pulsar is debated. For different kinds of radiation emitted the zone fluctuates, but it would have to lie close to the star (probably no greater than ~4-5 AU and maybe as less as ~0.01-1 AU).</p>
<p>To answer your question on feasibility to retain an atmosphere, it seems to be possible for super-earths (with dense atmospheres) to keep their atmospheres for a long period (up to trillions of years). From what I have read, the atmosphere must be hundreds of times thicker than our own. A reasonably strong, intrinsic magnetic field can help the planet retain it's atmosphere. The exact values for each of the exoplanet is discussed in your table. Eventually, these planets may be stripped off their atmospheres as well, however the time period is long enough to give rise to complex life-forms.</p>
<p>Presently, we do not know about any habitable pulsar planet.</p>

CC BY-SA 4.0
2024-11-03T19:09:09.937Z
out of curiosity, what about an earth-like world with an earth-like atmosphere with a much stronger magnetic field, say, what about as a moon of a jovian-mass gas giant, or what about a binary planet? or something that has a 12 or 10 hour rotational period or something with a much larger core? do you know how the magnetosphere strength is related to the atmospheric retention?
ArchiveOfStars
CC BY-SA 4.0
2024-11-03T20:23:50.083Z
I haven't seen much research on earth-like world and atmosphere with stronger magnetic field. However, it is my understanding that it is the atmospheric density which mitigates the heating effect of irradiation. A habitable pulsar planet's atmosphere is denser than earth's by a HUGE margin. Maybe in a perfectly ideal (and hypothetical) scenario the magnetic field would be strong enough to hold on to such a thin atmosphere. Atmosphere and magnetic field strength are related but it isn't the only criteria. Mercury and Venus are examples for this.
Anupama Mukherjee
CC BY-SA 4.0
2024-11-03T20:25:13.803Z
@ArchiveOfStars Off a tangent, maybe this will be interesting to you:
https://www.researchgate.net/publication/351924151_The_Influence_of_Planetary_Magnetic_Fields_on_Atmospheric_Retention_and_Habitability

https://academic.oup.com/mnras/article/506/2/1697/6308830
Anupama Mukherjee
CC BY-SA 4.0
2024-11-01T09:59:19.330Z
2024-11-01T10:21:15.263Z
2024-11-01T10:21:15.263Z
Anupama Mukherjee
<p>I was reading <a href="https://www.aanda.org/articles/aa/full_html/2017/12/aa31102-17/aa31102-17.html" rel="nofollow noreferrer">this article</a> discussing how on super-earth exoplanets orbiting in the habitable zone of a pulsar (such as PSR B1257+12 c and d) could hypothetically retain an atmosphere that is 1% the mass of the planet if said planet has an earth-like magnetic field (table below)</p>
<p><a href="https://i.sstatic.net/ZZE2slmS.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ZZE2slmS.jpg" alt="enter image description here" /></a></p>
<p>However, I am curious on what magnetic field strength would be required to keep an earth-like atmosphere with earth-like atmospheric pressure on such planets, and whether such planets would be habitable. Is it feasible for a terrestrial planet (1-8 earth masses) to retain an atmosphere identical or similar to what is seen on modern-day earth, and what conditions would be required in order for said atmosphere to avoid stripping from pulsar winds and x-ray radiation?</p>

CC BY-SA 4.0
2024-10-27T18:42:08.727Z
Venus has no magnetic field.  Magnetic fields are not the be-all-and-end-all of planetary atmospheres,
James K
CC BY-SA 4.0
2024-10-27T19:34:20.793Z
"habitable zone of a pulsar" sounds like an oxymoron ;)
Mithoron
CC BY-SA 4.0
2024-10-28T12:23:53.960Z
@Mithoron lol, for the way I understand planetary scientists/astrophysicist right now is "if it radiates energy, it has a habitable zone"
ArchiveOfStars
CC BY-SA 4.0
2024-10-28T18:05:02.327Z
@ArchiveOfStars: That's an incorrect undersanding. If it radiates ionizing radiation (which would be the hard radiation emitted by a pulsar), it's going to be hard to allow for life as we know it.
AtmosphericPrisonEscape
CC BY-SA 4.0
2024-10-28T21:43:35.180Z
@AtmosphericPrisonEscape 1: in the article it talks about how hard xrays and uv radiation like what is seen being emitted from a pulsar can be absorbed by a planetary atmosphere and be converted into heat before it reaches the surface 2. the habitable zone is defined as the zone where stable bodies of liquid water can exist on a planetary surface, not as an area that is particularly hospitable to life. 3, i was being sarcastic :)
ArchiveOfStars
CC BY-SA 4.0
2024-10-28T21:54:42.107Z
Indeed, i've seen this. However they don't calculate how such a thick atmosphere might be allowed to exist - the ionizing radiation would drive vigorous mass-loss in the upper atmosphere.
AtmosphericPrisonEscape
CC BY-SA 4.0
2024-11-02T14:52:05.560Z
@James K -  Venus has no internally generated magnetic field, but it does have a reasonably strong magnetosphere induced by the solar wind.
eshaya
CC BY-SA 4.0
2024-11-02T16:52:41.300Z
Yes, but the main thing that holds an atmosphere to a planet is gravity, not magnetism.
James K
<exoplanet><magnetic-field><pulsar><habitable-zone><atmospheric-escape>
Can an earth-like atmosphere survive on a pulsar planet?
ArchiveOfStars
# Can an earth-like atmosphere survive on a pulsar planet?

(Asked by: username_0 on 2024-10-27)

I was reading [this article](https://www.aanda.org/articles/aa/full_html/2017/12/aa31102-17/aa31102-17.html) discussing how on super-earth exoplanets orbiting in the habitable zone of a pulsar (such as PSR B1257+12 c and d) could hypothetically retain an atmosphere that is 1% the mass of the planet if said planet has an earth-like magnetic field (table below)

[![enter image description here](https://i.sstatic.net/ZZE2slmS.jpg)](https://i.sstatic.net/ZZE2slmS.jpg)

However, I am curious on what magnetic field strength would be required to keep an earth-like atmosphere with earth-like atmospheric pressure on such planets, and whether such planets would be habitable. Is it feasible for a terrestrial planet (1-8 earth masses) to retain an atmosphere identical or similar to what is seen on modern-day earth, and what conditions would be required in order for said atmosphere to avoid stripping from pulsar winds and x-ray radiation?

**Tags:** exoplanet, magnetic-field, pulsar, habitable-zone, atmospheric-escape

> **Comments:**
> **username_1**: Venus has no magnetic field.  Magnetic fields are not the be-all-and-end-all of planetary atmospheres,  
> **username_2**: "habitable zone of a pulsar" sounds like an oxymoron ;)  
> **username_0**: @username_2 lol, for the way I understand planetary scientists/astrophysicist right now is "if it radiates energy, it has a habitable zone"  
> **username_3**: @username_0: That's an incorrect undersanding. If it radiates ionizing radiation (which would be the hard radiation emitted by a pulsar), it's going to be hard to allow for life as we know it.  
> **username_0**: @username_3 1: in the article it talks about how hard xrays and uv radiation like what is seen being emitted from a pulsar can be absorbed by a planetary atmosphere and be converted into heat before it reaches the surface 2. the habitable zone is defined as the zone where stable bodies of liquid water can exist on a planetary surface, not as an area that is particularly hospitable to life. 3, i was being sarcastic :)  
> **username_3**: Indeed, i've seen this. However they don't calculate how such a thick atmosphere might be allowed to exist - the ionizing radiation would drive vigorous mass-loss in the upper atmosphere.  
> **username_4**: @username_1 -  Venus has no internally generated magnetic field, but it does have a reasonably strong magnetosphere induced by the solar wind.  
> **username_1**: Yes, but the main thing that holds an atmosphere to a planet is gravity, not magnetism.  

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## 1 answers

### Answer by username_5 on 2024-11-01. Score: 1 | Accepted answer

Pulsars emit large amounts of ionizing radiation. It has a very powerful magnetic field which causes it to 'release' jets of electron-positron pairs. Atmosphere in the pulsar planets escapes off due to the intense heating effect of the X-Rays. If a planet has a suitable magnetic field then it can minimize the effect of irradiation. Atmosphere of an earth-like planet will be stripped away in a relatively short time. Earth-like atmosphere with earth-like magnetosphere will not survive for long. This is short period of time insufficient for complex life-forms to evolve.

The habitable zone for a pulsar is debated. For different kinds of radiation emitted the zone fluctuates, but it would have to lie close to the star (probably no greater than ~4-5 AU and maybe as less as ~0.01-1 AU).

To answer your question on feasibility to retain an atmosphere, it seems to be possible for super-earths (with dense atmospheres) to keep their atmospheres for a long period (up to trillions of years). From what I have read, the atmosphere must be hundreds of times thicker than our own. A reasonably strong, intrinsic magnetic field can help the planet retain it's atmosphere. The exact values for each of the exoplanet is discussed in your table. Eventually, these planets may be stripped off their atmospheres as well, however the time period is long enough to give rise to complex life-forms.

Presently, we do not know about any habitable pulsar planet.

> **Comments:**
> **username_0**: out of curiosity, what about an earth-like world with an earth-like atmosphere with a much stronger magnetic field, say, what about as a moon of a jovian-mass gas giant, or what about a binary planet? or something that has a 12 or 10 hour rotational period or something with a much larger core? do you know how the magnetosphere strength is related to the atmospheric retention?  
> **username_5**: I haven't seen much research on earth-like world and atmosphere with stronger magnetic field. However, it is my understanding that it is the atmospheric density which mitigates the heating effect of irradiation. A habitable pulsar planet's atmosphere is denser than earth's by a HUGE margin. Maybe in a perfectly ideal (and hypothetical) scenario the magnetic field would be strong enough to hold on to such a thin atmosphere. Atmosphere and magnetic field strength are related but it isn't the only criteria. Mercury and Venus are examples for this.  
> **username_5**: @username_0 Off a tangent, maybe this will be interesting to you: https://www.researchgate.net/publication/351924151_The_Influence_of_Planetary_Magnetic_Fields_on_Atmospheric_Retention_and_Habitability  https://academic.oup.com/mnras/article/506/2/1697/6308830  

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