Stars with superpowered magnetic fields could narrow the search for alien life

Plasma physics is very hard to comprehend due to:
- It is recursive. Changing electric field creates changing magnetic field which creates a changing electric field and another changing magnetic field and so on. - Charged particles are pushed at right angles to magnetic fields.
- The forces due to charges are 10^41 times stronger than the gravitational forces at work.
- 1840 times difference in mass between positive particles (mostly protons) and negative particles (mostly electrons) thus huge mobility differences
 
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This report seems consistent with the known tantrums issued by the fiesty red dwarf class of stars. It will be great to see their spots, once we can.

But red dwarfs live a long life, so the question becomes whether life could emerge when, and if, they settle down. It seems obvious that such life is less likely given the abuse any planet would have endured under those stellar activities.
 
Perhaps life will learn to live deep underground to avoid surface variability.

Certainly an abundance of high energy charged particles to encourage nearly any chemical reaction. Life might live in underground conduits like geysers have.
 
Perhaps life will learn to live deep underground to avoid surface variability.

Certainly an abundance of high energy charged particles to encourage nearly any chemical reaction. Life might live in underground conduits like geysers have.
Yes, good point. There is interesting argument that favors life having begun at ocean vents.

But advanced life forms might need a terrestrial evolutionary path. So perhaps the greater chances are with the, say, F7 to K9 star types. K9 stars, however, might limit upper evolution to some sort of canine animal. ;)
 
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A big gamma ray burst might kill all the humans except those deep underground in the gold mines. They would surface to find a landscape of complete death. The cockroaches would be in charge. It would be payback time. They would take all the good tables at the finer restaurants. Humans would have a short lived feast on dead animals but there would be no new food. Seeds would not sprout. They'd be screwed. We'd be dead. We wouldn't care.
 
From the paper cited, Core-envelope Decoupling Drives Radial Shear Dynamos in Cool Stars, https://iopscience.iop.org/article/10.3847/2041-8213/acd780, 17-July-2023. “Abstract Differential rotation is thought to be responsible for the dynamo process in stars like our Sun, driving magnetic activity and starspots. We report that starspot measurements in the Praesepe open cluster are strongly enhanced only for stars that depart from standard models of rotational evolution. A decoupling of the spin-down history between the core and envelope explains both the activity and rotation anomalies: surface rotational evolution is stalled by interior angular momentum redistribution, and the resultant radial shears enhance starspot activity. These anomalies provide evidence for an evolving front of shear-enhanced activity affecting the magnetic and rotational evolution of cool stars and the high-energy environments of their planetary companions for hundreds of millions to billions of years on the main sequence.”

My note, from the 10-page PDF report on page 6. “We show in this work that core-envelope decoupling and stalled spin down are linked, producing observables not only in angular momentum evolution but also in activity. The existence of shear-enhanced magnetism suggests that stellar mixing processes can persist for hundreds of millions to billions of years—consistent with models where waves are the primary mechanism linking the cores and envelopes of stars. Evolutionary models will need to include core-envelope decoupling and angular momentum losses from dynamos with large coreenvelope shears to obtain accurate rotation-based ages on the main sequence. Habitability models will need to be informed by the enhanced magnetism associated with core-envelope decoupling as shear-enhanced activity can last for billions of
years in low-mass stars. Decoupling signals in activity and rotation are strongly mass- and age-dependent and are potential age diagnostics for low-mass main-sequence stars, where there are other age indicators are scarce.”

My note from the paper, “Habitability models will need to be informed by the enhanced magnetism associated with core-envelope decoupling as shear-enhanced activity can last for billions of
years in low-mass stars.” Seems there is plenty to chew on now for smaller stars having habitable exoplanets, if any. Rogue planets are back in the news too. If rogue planets are everywhere, how could we explore them?, https://phys.org/news/2023-07-rogue-planets-explore.html, “At one time, astronomers believed that the planets formed in their current orbits, which remained stable over time. But more recent observations, theory, and calculations have shown that planetary systems are subject to shake-ups and change. Periodically, planets are kicked out of their star systems to become "rogue planets," bodies that are no longer gravitationally bound to any star and are adrift in the interstellar medium (ISM)…” Ref - Chasing nomadic worlds: A new class of deep space missions, https://www.sciencedirect.com/science/article/abs/pii/S009457652300379X?via=ihub, 25-July-2023. “Abstract Nomadic worlds, i.e., objects not gravitationally bound to any star(s), are of great interest to planetary science and astrobiology. They have garnered attention recently on account of constraints derived from microlensing surveys and the recent discovery of interstellar planetesimals.”

IMO, finding habitable exoplanets is becoming more challenging it seems. What astronomy is learning today about exoplanets is very different than Charles Darwin model for abiogenesis taking place in the warm little pond (where no life today would eat the developing non-living matter before it evolves into a cell) published in his 1871 and 1882 letters.
 
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A big gamma ray burst might kill all the humans except those deep underground in the gold mines. They would surface to find a landscape of complete death. The cockroaches would be in charge. It would be payback time. They would take all the good tables at the finer restaurants. Humans would have a short lived feast on dead animals but there would be no new food. Seeds would not sprout. They'd be screwed. We'd be dead. We wouldn't care.
Are you suggesting a grb could have been a real possibility long ago? The Sun likely was part of a cluster of less than 3000 stars, so the IMF favors only a few stars of a massive size. I would guess a life sterilizing grb would be more unlikely than likely. I suspect we could see such a sterilization in ancient rock, especially lunar rocks, but I'm guessing.

I've forgotten if the pre-Theia impact had the Earth with a thicker atmosphere, this would have helped if such an event took place.
 
Yes, I can't quote sources, but there is one of the mass extinctions they can't find evidence of volcanism or iridium from an impactor. GRB was their most probable cause.
Bad thing about GRB is there is no possible way of warning.

GRB221009A last October, brightest GRB ever seen. Disrupted radio transmissions. This, from a distance of 1.8 million light years.


In the entire history of high energy gamma ray observing, there were but 100 or 200 examples. This GRB produced 5,000 such photons. It is estimated to be a 1:10,000 years event.
 
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From the paper cited, Core-envelope Decoupling Drives Radial Shear Dynamos in Cool Stars, https://iopscience.iop.org/article/10.3847/2041-8213/acd780, 17-July-2023. “Abstract Differential rotation is thought to be responsible for the dynamo process in stars like our Sun, driving magnetic activity and starspots. We report that starspot measurements in the Praesepe open cluster are strongly enhanced only for stars that depart from standard models of rotational evolution. A decoupling of the spin-down history between the core and envelope explains both the activity and rotation anomalies: surface rotational evolution is stalled by interior angular momentum redistribution, and the resultant radial shears enhance starspot activity. These anomalies provide evidence for an evolving front of shear-enhanced activity affecting the magnetic and rotational evolution of cool stars and the high-energy environments of their planetary companions for hundreds of millions to billions of years on the main sequence.”
Little red dwarfs are fully convective, so nothing spins like a solid would. The Sun spins like a solid, they think, for the core and radiative zones, but convective for the outer zone. The boundary is called the tachocline. I've tended to think this is the place where the seeds for storms begin -- like trailer parks for tornadoes. ;)


Habitability models will need to be informed by the enhanced magnetism associated with core-envelope decoupling as shear-enhanced activity can last for billions of years in low-mass stars. Decoupling signals in activity and rotation are strongly mass- and age-dependent and are potential age diagnostics for low-mass main-sequence stars, where there are other age indicators are scarce.”
But these low mass stars can have a life up to about a trillion years, so a few billion years is long before maturity, whatever that looks like. There should be some older red dwarfs that may exhibit fewer tantrums, or has this been studied already? They are hard to see because they are so dim, so these new giant scopes will offer a great deal more in this area, no doubt. The JWST should help as well given it's longer wavelength advantages.

Rogue planets are back in the news too. If rogue planets are everywhere, how could we explore them?, https://phys.org/news/2023-07-rogue-planets-explore.html, “At one time, astronomers believed that the planets formed in their current orbits, which remained stable over time. But more recent observations, theory, and calculations have shown that planetary systems are subject to shake-ups and change.
I have seen descriptions of the early solar system as a pin-ball machine due to all the wild dynamics. The Nice model, IIRC, manages to predict, after wild orbital shifts, all the current planetary orbital locations with the exception of Pluto, so it's not a perfect model.

I think stability came after Jupiter and Saturn found their resonance with one another, but that is going on my memory as well.

These dynamics may have tossed large bodies outward, including Planet 9, if one is ever found.

Given the large number of massive stars found, the observations of more rogue planets seems logical. Space is so big, however, that odds don't favor one coming our way. But, who knows, at least two interstellar objects have paid us a visit, ignoring UFO's, of course. ;)


IMO, finding habitable exoplanets is becoming more challenging it seems.
I'm unsure what you mean by more challenging. Progress for greater capability of discovery is only getting better.

HZ exos are certainly rare. I find only about a dozen with over 5400 confirmed that are about the size of Earth and likely are capable of having liquid water. IMO, the number is likely about 2 or 3x this figure due to the lack of proper equations that define boundaries. The equilibrium temp. method places the Earth outside the HZ, for instances.

But if we extrapolate the, say, 10 HZ exos per 5000 stars, then this number becomes ~200 million for our galaxy assuming only 100 billion stars. But many, if not most, will have unfavorable orbits around the galaxy. Too far out, and poor metal concentrations are possible. Too close may find too turbulent an environment.

However, after running the program just now, using what I call the "Kopp" method (atmospheric approach), there is only one exo that is in the HZ that is close to the size of Earth.
 
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Yes, I can't quote sources, but there is one of the mass extinctions they can't find evidence of volcanism or iridium from an impactor. GRB was their most probable cause.
Bad thing about GRB is there is no possible way of warning.

GRB221009A last October, brightest GRB ever seen. Disrupted radio transmissions. This, from a distance of 2.4 million light years.

Yes, I recall SGR1806 being brighter than any other object in the galaxy when it went nuts. But, as you show, brighter ones have come since.
 
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They said it was a jet aimed at us. Had an isotopic intrinsic energy release of 4+/-2x10^54 ergs at a distance of 1.8 million light years.

A sphere of that radius would have a surface area of 4 pi (1.8e6 LY x 9e15 m/LY)^2 or 7.6e45 m^2 or 7.6e49 cm^2.

Here at Earth the energy deposition per square cm would have been 4e54 divided by 7.6e49 cm^2 or 52,000 ergs/cm^2. That is .052 joule/cm^2. That is a 50 milliwatt gamma ray beam for 1 second. Basically a dental x-ray.
 
Little red dwarfs are fully convective, so nothing spins like a solid would. The Sun spins like a solid, they think, for the core and radiative zones, but convective for the outer zone. The boundary is called the tachocline. I've tended to think this is the place where the seeds for storms begin -- like trailer parks for tornadoes. ;)



But these low mass stars can have a life up to about a trillion years, so a few billion years is long before maturity, whatever that looks like. There should be some older red dwarfs that may exhibit fewer tantrums, or has this been studied already? They are hard to see because they are so dim, so these new giant scopes will offer a great deal more in this area, no doubt. The JWST should help as well given it's longer wavelength advantages.


I have seen descriptions of the early solar system as a pin-ball machine due to all the wild dynamics. The Nice model, IIRC, manages to predict, after wild orbital shifts, all the current planetary orbital locations with the exception of Pluto, so it's not a perfect model.

I think stability came after Jupiter and Saturn found their resonance with one another, but that is going on my memory as well.

These dynamics may have tossed large bodies outward, including Planet 9, if one is ever found.

Given the large number of massive stars found, the observations of more rogue planets seems logical. Space is so big, however, that odds don't favor one coming our way. But, who knows, at least two interstellar objects have paid us a visit, ignoring UFO's, of course. ;)



I'm unsure what you mean by more challenging. Progress for greater capability of discovery is only getting better.

HZ exos are certainly rare. I find only about a dozen with over 5400 confirmed that are about the size of Earth and likely are capable of having liquid water. IMO, the number is likely about 2 or 3x this figure due to the lack of proper equations that define boundaries. The equilibrium temp. method places the Earth outside the HZ, for instances.

But if we extrapolate the, say, 10 HZ exos per 5000 stars, then this number becomes ~200 million for our galaxy assuming only 100 billion stars. But many, if not most, will have unfavorable orbits around the galaxy. Too far out, and poor metal concentrations are possible. Too close may find too turbulent an environment.

However, after running the program just now, using what I call the "Kopp" method (atmospheric approach), there is only one exo that is in the HZ that is close to the size of Earth.
Helio, you said *I'm unsure what you mean by more challenging*. I am not pointing out discovery methods improving that could make for better observations, but more astronomical constraints appear for habitable exoplanets as time goes by. The 10-page paper made this clear when discussing briefly habitability and so too the space.com article. "This new research suggests unexpectedly intense magnetic fields arise around cool, small stars when the surfaces and interiors of those stars start out by rotating at the same speed but, over time, drift apart and spin out of sync. The team behind the study calls that internal mechanism core-envelope decoupling, a process that could ultimately impact our search for life elsewhere in the Milky Way. "Stellar physics can have surprising implications for other fields," Lyra Cao, team lead and an astronomy graduate student at Ohio State University, said in a statement. "Stars experiencing this enhanced magnetism are likely going to be battering their planets with high-energy radiation. This effect is predicted to last for billions of years on some stars, so it’s important to understand what it might do to our ideas of habitability."

Edit. Charles Darwin did not think like this in his 1871 and 1882 letters on the warm little pond. In his 1882 letter he hoped that someday a general law of nature would be found for abiogenesis. IMO, all the discussions about habitable exoplanets or constraints limiting their habitable zones or conditions for life, seems to assume a general law of nature operating that repeats abiogenesis, over, and over again so life can evolve, even for a red dwarf star that starts out hostile for life but settles down, perhaps hundreds of billions of years from now. As far as I know, no general law of nature has been published showing a general law for abiogenesis like we have for Kepler or Newton that Charles Darwin hoped for in science.
 
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They said it was a jet aimed at us. Had an isotopic intrinsic energy release of 4+/-2x10^54 ergs at a distance of 1.8 million light years.

A sphere of that radius would have a surface area of 4 pi (1.8e6 LY x 9e15 m/LY)^2 or 7.6e45 m^2 or 7.6e49 cm^2.

Here at Earth the energy deposition per square cm would have been 4e54 divided by 7.6e49 cm^2 or 52,000 ergs/cm^2. That is .052 joule/cm^2. That is a 50 milliwatt gamma ray beam for 1 second. Basically a dental x-ray.
That’s too specific to be plausible, IMO. Is there any dwarf galaxy at that distance? The blast would be non- homogeneous, perhaps more gaussian, so this would affect intensity and distance values.
 
Helio, you said *I'm unsure what you mean by more challenging*. I am not pointing out discovery methods improving that could make for better observations, but more astronomical constraints appear for habitable exoplanets as time goes by.
Agreed. But even if we rule out all M class stars, we still have discovered more G class than M class exos.

It’s always been the safer bet that we are quite rare in our galaxy, possibly unique in our intelligence level. But we need to look at a million stars with planets in favorable galactic orbits, not just a few thousand.


Edit. Charles Darwin did not think like this in his 1871 and 1882 letters on the warm little pond. In his 1882 letter he hoped that someday a general law of nature would be found for abiogenesis. IMO, all the discussions about habitable exoplanets or constraints limiting their habitable zones or conditions for life, seems to assume a general law of nature operating that repeats abiogenesis, over, and over again so life can evolve, even for a red dwarf star that starts out hostile for life but settles down, perhaps hundreds of billions of years from now. As far as I know, no general law of nature has been published showing a general law for abiogenesis like we have for Kepler or Newton that Charles Darwin hoped for in science.
Right, if there were in law defining a real phenomena for abiogenesis then we’d all hear of it.

Step one is to assume we need certain key elements for life, liquid water being the first thing, and easiest, to find first, though indirectly ( ie HZs). But atmospheric spectroscopy is greatly improving.
 
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It is not clear how they arrived at the 10^54 number.
- Was that the observed jet intensity assumed for the entire sphere?
- Was the jet intensity and size integrated then spread out to cover the sphere?
 
It is not clear how they arrived at the 10^54 number.
- Was that the observed jet intensity assumed for the entire sphere?
- Was the jet intensity and size integrated then spread out to cover the sphere?
There are no dwarf galaxies at 1.5 Mlyrs, but perhaps the Phoenix dwarf galaxy at 1.44 Mlyrs. hosted this GRB, assuming their distance calculation was, somehow, accurately determined. It's hard to imagine it would be all by its self.

The Phoenix is -44 deg. declination, so this might have not done that much damage to the north, but that would depend on our inclination at that moment.
 
Yes, and with a massive GRB, exactly half the Earth's surface would be spared.

At 1,500,000 LY, a 10^54 erg blast deposits .05 joule per cm^2 here on Earth.
At. say 10,000 LY it would be 22,500 joules per cm^2. Ouch.
 
Agreed. But even if we rule out all M class stars, we still have discovered more G class than M class exos.

It’s always been the safer bet that we are quite rare in our galaxy, possibly unique in our intelligence level. But we need to look at a million stars with planets in favorable galactic orbits, not just a few thousand.



Right, if there were in law defining a real phenomena for abiogenesis then we’d all hear of it.

Step one is to assume we need certain key elements for life, liquid water being the first thing, and easiest, to find first, though indirectly ( ie HZs). But atmospheric spectroscopy is greatly improving.
"It’s always been the safer bet that we are quite rare in our galaxy, possibly unique in our intelligence level. But we need to look at a million stars with planets in favorable galactic orbits, not just a few thousand."

Helio, interesting number here *look at a million stars with planets*. Currently the exoplanet.eu site shows 4047 stars with planets (unique names) and the NASA archive site shows 4087 host star unique names. In Charles Darwin 1882 letter, he did not think there was any worthwhile evidence presented in the science of his day to show non-living matter evolved into a living cell. You gave me some numbers here to ponder.
 
Helio, interesting number here *look at a million stars with planets*. Currently the exoplanet.eu site shows 4047 stars with planets (unique names) and the NASA archive site shows 4087 host star unique names.
That gives us ~ 80% of the known stars w/ only one (so far) exo. But this percent will drop greatly as these were the low-hanging fruit. The harder to observe smaller ones and those with distant orbits, plus non-favorable inclination exos, will grow in number.
In Charles Darwin 1882 letter, he did not think there was any worthwhile evidence presented in the science of his day to show non-living matter evolved into a living cell. You gave me some numbers here to ponder.
Not only was abiogenesis beyond their scientific grasp — it still is— but his greater struggle could have been avoided had he realized the works of the monk Mendel. His first edition ignored speculating on how traits physically transferred to off-spring. He dreamed-up an explanation on subsequent editions, but to his detriment. But no one else offered this important element in the other theories at that time. It took genetics to win the majority of scientists to his theory.
 
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Here is another report on stellar winds driven by magnetic field activity.

Cool stars with powerful winds threaten exoplanetary atmospheres, https://phys.org/news/2023-08-cool-stars-powerful-threaten-exoplanetary.html

"...The investigation obtained an assessment of how strong the winds of these stars are at the so-called "habitable zones," defined as the orbital distances at which rocky exoplanets could sustain surface liquid water, provided an Earth-like atmospheric pressure. They found milder conditions around F and G-type stars, comparable to what the Earth experiences around the G-type sun, and increasingly harsher wind environments for K and M-type stars. Such intense stellar winds strongly affect any potential atmosphere the planet might have. This phenomenon is well documented in solar physics between rocky planets and the sun, but not in the case of exoplanetary systems. This requires estimates of the stellar wind to assess processes similar to those we see between the solar winds and planetary atmospheres. Information on the stellar wind was previously unknown for F to M main sequence stars, making this study important in the context of habitability. The work presented in this paper was done for 21 stars, but the results are general enough to be applied to other cool main sequence stars. This investigation paves the way for future research on stellar wind observations and their impact on the erosion of planetary atmospheres."

My note, more constraints appear in this report on stellar magnetic activity and stellar winds for abiogenesis to take place on an exoplanet and astrobiology studies.

ref - Numerical quantification of the wind properties of cool main sequence stars, https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/stad2100/7226714?login=false, 19-July-2023.

"...Furthermore, our 3D models encompass the entire classical Habitable Zones (HZ) of all the stars in our sample. This allows us to provide the stellar wind dynamic pressure at both edges of the HZ and analyse the variations of this parameter across spectral type and orbital inclination. The results here presented could serve to inform future studies of stellar wind-magnetosphere interactions and stellar wind erosion of planetary atmospheres via ion escape processes."

My observation, an interesting table using real stars to compare with the model in the paper. "Table 1.Fundamental parameters of our sample. Columns 1–8 list the star number, name, SpT, stellar mass (M⋆), stellar radius (R⋆⁠), rotation period (⁠Prot⁠), effective temperature (⁠Teff⁠), and luminosity (L⋆), respectively (See et al. 2019a and references therein)." My note, some or perhaps many of these stars listed in the table host exoplanets like Tau Boo system. The paper concludes - 4 SUMMARY AND CONCLUSIONS...Finally, the properties of the stellar wind in the HZ of different SpTs obtained here can be used in future studies to, for instance, estimate the expected radio emission due to wind-magnetosphere interactions or the planetary atmospheric mass-loss due to erosion of the stellar wind from ion escape processes." My note. Abiogenesis assumed to take place on some exoplanets must include stellar winds that could erode exoplanet atmospheres because of magnetic field activity, another constraint appears.
 
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Perhaps life will learn to live deep underground to avoid surface variability.

Certainly an abundance of high energy charged particles to encourage nearly any chemical reaction. Life might live in underground conduits like geysers have.
Hi,

The idea of life adapting to live deep underground to escape surface variability is fascinating. The abundance of high-energy charged particles could indeed fuel diverse chemical reactions, potentially supporting unique life forms.
 
My note. Abiogenesis assumed to take place on some exoplanets must include stellar winds that could erode exoplanet atmospheres because of magnetic field activity, another constraint appears.
This paper may not do a great job of arguing that case. Notice the reference another paper that states the Earth may be experiencing greater ion loss (6E24/sec). It does, however, show the science in determining the strength of winds. They do not that exoplanets may have stronger magnetic fields than Earth, thus allowing protection.

Here's the quote (just above the Summary section):
"In fact, they reported an ion loss for Earth that ranges from 6 × 1024 ions s−1 to 6 × 1026 ions s−1, which is higher than what Venus and Mars lose..."