Free Range Planet/Brown Dwarf
- nick c
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Free Range Planet/Brown Dwarf
While reading a post from a year ago on another thread I stumbled on this link:
http://www.astronomy.com/news/2018/08/free-range-planet
I wonder if anyone has come up with more on this story. Seems pretty interesting.
http://www.astronomy.com/news/2018/08/free-range-planet
I wonder if anyone has come up with more on this story. Seems pretty interesting.
- Solar
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Re: Free Range Planet/Brown Dwarf
Another article here VLA Detects Possible Extrasolar Planetary-Mass Magnetic Powerhouse about SIMP J01365663+0933473 references the below paper:
The Strongest Magnetic Fields on the Coolest Brown Dwarfs: Melodie Kao, Gregg Hallinan et al
Here is an interesting followup reference:
A Panchromatic View of Brown Dwarf Aurorae: J. Sebastian Pineda, Gregg Hallinan, Melodie M. Kao
Nice technique being used.
The Strongest Magnetic Fields on the Coolest Brown Dwarfs: Melodie Kao, Gregg Hallinan et al
Here is an interesting followup reference:
A Panchromatic View of Brown Dwarf Aurorae: J. Sebastian Pineda, Gregg Hallinan, Melodie M. Kao
Nice technique being used.
"Our laws of force tend to be applied in the Newtonian sense in that for every action there is an equal reaction, and yet, in the real world, where many-body gravitational effects or electrodynamic actions prevail, we do not have every action paired with an equal reaction." — Harold Aspden
- nick c
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Re: Free Range Planet/Brown Dwarf
Solar,
Thanks for the links.
From the abstract of The Strongest Magnetic Fields on the Coolest Brown Dwarfs
Thanks for the links.
From the abstract of The Strongest Magnetic Fields on the Coolest Brown Dwarfs
Mainstream stellar theory is strained to explain this type of celestial object.Finally, we find that age, mass, and temperature together cannot account for the strong magnetic fields produced by our targets.
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Re: Free Range Planet/Brown Dwarf
The VLA article also states that the finding “presents huge challenges to our understanding of the dynamo mechanism" as well.
These works are still using the ‘rapidly spinning’ concept (dynamos with this one in particular) saying “emerging consensus that rapid rotation may be important for producing strong dipole fields in convective dynamos and/or (ii) rapid rotation is a key ingredient for driving the current systems powering auroral radio emission.” The operative word being “may” which underscores the aforementioned "challenges".
They detect “highly circularly polarized radio pulses” and attribute the cause to “electron cyclotron maser (ECM) instability” which they say “… is the same process driving auroral radio emissions in the magnetized Solar System planets.” So there appears to be recognition of plasma instabilities in these works. according to another paper the proposed “ECM” is “radiation by a beam of fast electrons traveling in a magnetized plasma…”
Electron cyclotron maser (ECM) instability
The aptly named “pulsar” (Jocelyn Bell has recently been recognized for her contributions) which were later considered to be some sort of ‘rapidly rotating neutron star’ by Thomas Gold is also being considered from the point of view of resonantly “Pulsed Plasma”.
Oddly enough though there is also blending of models called the “Pulsar Gap Model” (thank you to member Gary N) which theoretically isolates the pulsatory activity to relatively small areas at polar regions however, the “rapidly spinning” component is still incorporated.
If interested parties visit: Why and How to Pulse a Plasma
… (nearly) all of the necessary dynamic components (See “Regimes” & “RF” section) are available for contrast without need of anything necessarily "rapidly spinning" at all.
These works are still using the ‘rapidly spinning’ concept (dynamos with this one in particular) saying “emerging consensus that rapid rotation may be important for producing strong dipole fields in convective dynamos and/or (ii) rapid rotation is a key ingredient for driving the current systems powering auroral radio emission.” The operative word being “may” which underscores the aforementioned "challenges".
They detect “highly circularly polarized radio pulses” and attribute the cause to “electron cyclotron maser (ECM) instability” which they say “… is the same process driving auroral radio emissions in the magnetized Solar System planets.” So there appears to be recognition of plasma instabilities in these works. according to another paper the proposed “ECM” is “radiation by a beam of fast electrons traveling in a magnetized plasma…”
Electron cyclotron maser (ECM) instability
The aptly named “pulsar” (Jocelyn Bell has recently been recognized for her contributions) which were later considered to be some sort of ‘rapidly rotating neutron star’ by Thomas Gold is also being considered from the point of view of resonantly “Pulsed Plasma”.
Oddly enough though there is also blending of models called the “Pulsar Gap Model” (thank you to member Gary N) which theoretically isolates the pulsatory activity to relatively small areas at polar regions however, the “rapidly spinning” component is still incorporated.
If interested parties visit: Why and How to Pulse a Plasma
… (nearly) all of the necessary dynamic components (See “Regimes” & “RF” section) are available for contrast without need of anything necessarily "rapidly spinning" at all.
"Our laws of force tend to be applied in the Newtonian sense in that for every action there is an equal reaction, and yet, in the real world, where many-body gravitational effects or electrodynamic actions prevail, we do not have every action paired with an equal reaction." — Harold Aspden
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Re: Free Range Planet/Brown Dwarf
What is really suspicious in that sort of discovery that the maximum resolution of VLA is about 0.043 arcsec.
https://science.nrao.edu/facilities/vla ... resolution
Which is approx 2e-7 radians.
Jupiter size planet on the distance of 20 ly will be visible at 1.85e-11 radians.
Kind of strange to see something four orders of magnitude smaller compare to your maximum resolution.
https://science.nrao.edu/facilities/vla ... resolution
Which is approx 2e-7 radians.
Jupiter size planet on the distance of 20 ly will be visible at 1.85e-11 radians.
Kind of strange to see something four orders of magnitude smaller compare to your maximum resolution.
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