APOD: A Filament Leaps from the Sun (2021 Nov 08)

[APOD Robot]

A Filament Leaps from the Sun

Explanation: Why, sometimes, does part of the Sun's atmosphere leap into space? The reason lies in changing magnetic fields that thread through the Sun's surface. Regions of strong surface magnetism, known as active regions, are usually marked by dark sunspots. Active regions can channel charged gas along arching or sweeping magnetic fields -- gas that sometimes falls back, sometimes escapes, and sometimes not only escapes but impacts our Earth. The featured one-hour time-lapse video -- taken with a small telescope in France -- captured an eruptive filament that appeared to leap off the Sun late last month. The filament is huge: for comparison, the size of the Earth is shown on the upper left. Just after the filament lifted off, the Sun emitted a powerful X-class flare while the surface rumbled with a tremendous solar tsunami. A result was a cloud of charged particles that rushed into our Solar System but mostly missed our Earth -- this time. However, enough solar plasma did impact our Earth's magnetosphere to create a few faint auroras.

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[tennisjazz]

the link at missed our Earth is to https://www.bleachernation.com/wp-conte ... py-cat.jpg but yields:

Error 1011 Ray ID: 6aace38d18a661ee • 2021-11-08 06:54:14 UTC
Access denied
What happened?
The owner of this website (www.bleachernation.com) does not allow hotlinking to that resource (/wp-content/uploads/2012/12/relieved-happy-cat.jpg).

[VictorBorun]

the link at missed our Earth is to https://www.bleachernation.com/wp-conte ... py-cat.jpg but yields:

Error 1011 Ray ID: 6aace38d18a661ee • 2021-11-08 06:54:14 UTC
Access denied
What happened?
The owner of this website (www.bleachernation.com) does not allow hotlinking to that resource (/wp-content/uploads/2012/12/relieved-happy-cat.jpg).

https://www.bleachernation.com/wp-conte ... py-cat.jpg

relieved-happy-cat.jpg (15.71 KiB) Viewed 6083 times

[VictorBorun]

sunshine cat. But some of the sunshine we are glad to miss

[orin stepanek]

Wonder If sun is constantly losing weight; [mass] during solar flares that escape!

[neufer]

Wonder If sun is constantly losing weight; [mass] during solar flares that escape!

<<The mass of the Sun has been decreasing since the time it formed.
This occurs through two processes in nearly equal amounts:

• First, in the Sun's core, hydrogen is converted into helium through nuclear fusion, in particular the p–p chain, and this reaction converts some mass into energy in the form of gamma ray photons. Most of this energy eventually radiates away from the Sun.
  
  Second, high-energy protons and electrons in the atmosphere of the Sun are ejected directly into outer space as the solar wind and coronal mass ejections.

The original mass of the Sun at the time it reached the main sequence remains uncertain. The early Sun had much higher mass-loss rates than at present, and it may have lost anywhere from 1–7% of its natal mass over the course of its main-sequence lifetime. The Sun gains a very small amount of mass through the impact of asteroids and comets. However, as the Sun already contains 99.86% of the Solar System's total mass, these impacts cannot offset the mass lost by radiation and ejection.

The Sun is currently expelling about (2–3)×10⁻¹⁴ M_☉ per year. The mass loss rate will increase when the Sun enters the red giant stage, climbing to (7–9)×10⁻¹⁴ M_☉ per year when it reaches the tip of the red-giant branch. This will rise to 10⁻⁶ M_☉ per year on the asymptotic giant branch, before peaking at a rate of 10⁻⁵ to 10⁻⁴ M_☉ per year as the Sun generates a planetary nebula. By the time the Sun becomes a degenerate white dwarf, it will have lost 46% of its starting mass.>>

[orin stepanek]

Thanks Art!

[heehaw]

The surface gravity on the sun is 28 times greater than our surface gravity, here on Earth.
Yet the sun is able on a daily basis to blast flares having mass 1.6 X 10^12 kg (3.5 ≈ 10^12 lb) out into the solar system and beyond.
How does it do this? It's magnetic field. Which is only 1 Gauss. Earth's is ~0.5 Gauss.
I guess the difference is that the sun is completely gaseous, so sunspots can form with magnetic field 1000 to 2000 gauss.
I'm still utterly amazed that so much mass can be launched!
Makes NASA look like a pitiful weakling!

[neufer]

The surface gravity on the sun is 28 times greater than our surface gravity, here on Earth.
Yet the sun is able on a daily basis to blast flares having mass 1.6 X 10¹² kg out into the solar system and beyond.
How does it do this? It's magnetic field. Which is only 1 Gauss. Earth's is ~0.5 Gauss.
I guess the difference is that the sun is completely gaseous, so sunspots can form with magnetic field 1000 to 2000 gauss.

I'm still utterly amazed that so much mass can be launched!

• Note that that magnetic field is twisted (in a helical structure).

<<twisted (adj.) late 15c., "intertwined, past-participle adjective from twist (v.). Meaning "perverted, mentally strange" (1900) probably is from twist (n.) in a sense of "mental peculiarity, perversion" attested by 1811.
............................................................
twist (n.): All original senses suggest "dividing in two" (source also of cognate Old Norse tvistra "to divide, separate," Gothic twis- "in two, asunder," Dutch twist, German zwist "quarrel, discord"), but later ones are of "combining two into one," hence the original sense of the word may be "rope made of two strands." Meaning "thread or cord composed of two or more fibers" is recorded from 1550s. Meaning "act or action of turning on an axis" is attested from 1570s. Sense of "beverage consisting of two or more liquors" is first attested c. 1700. Meaning "curled piece of lemon, etc., used to flavor a drink" is recorded from 1958. Sense of "unexpected plot development" is from 1941. To get one's knickers in a twist "be unduly agitated" is British slang first attested 1971.
............................................................
twist (v.) c. 1200 (implied in past tense form twaste), "to wring," from twist (n.). Sense of "to spin two or more strands of yarn into thread" is attested from late 15c. Meaning "to move in a winding fashion" is recorded from 1630s.
............................................................
filament (n.) "fine untwisted thread, separate fibril," 1590s, from Modern Latin filamentum, from Late Latin filare "to spin, draw out in a long line," from Latin filum "thread." As the name of the incandescent element in a light-bulb , from 1881.>>

Magnetic reconnection: This view is a cross-section through four magnetic domains undergoing separator reconnection. Two separatricesdivide space into four magnetic domains with a separator at the center of the figure. Field lines (and associated plasma) flow inward from above and below the separator, reconnect, and spring outward horizontally. A current sheet (as shown) may be present but is not required for reconnection to occur. This process is not well understood: once started, it proceeds many orders of magnitude faster than predicted by standard models.

---

<<The phenomenon of magnetic reconnection is closely associated with Coronal mass ejections (CMEs) and solar flares. In magnetohydrodynamic theory, the sudden rearrangement of magnetic field lines when two oppositely directed magnetic fields are brought together is called "magnetic reconnection". Reconnection releases energy stored in the original stressed magnetic fields. These magnetic field lines can become twisted in a helical structure, with a 'right-hand twist' or a 'left-hand twist'. As the Sun's magnetic field lines become more and more twisted, CMEs appear to be a 'valve' to release the magnetic energy being built up, as evidenced by the helical structure of CMEs, that would otherwise renew itself continuously each solar cycle and eventually rip the Sun apart.

On the Sun, magnetic reconnection may happen on solar arcades—a series of closely occurring loops of magnetic lines of force. These lines of force quickly reconnect into a low arcade of loops, leaving a helix of magnetic field unconnected to the rest of the arcade. The sudden release of energy during this process causes the solar flare and ejects the CME. The helical magnetic field and the material that it contains may violently expand outwards forming a CME. This also explains why CMEs and solar flares typically erupt from what are known as the active regions on the Sun where magnetic fields are much stronger on average.

A current problem in plasma physics is that observed reconnection happens much faster than predicted by MHD in high Lundquist number plasmas (i.e. fast magnetic reconnection). Solar flares, for example, proceed 13–14 orders of magnitude faster than a naive calculation would suggest, and several orders of magnitude faster than current theoretical models that include turbulence and kinetic effects. One possible mechanism to explain the discrepancy is that the electromagnetic turbulence in the boundary layer is sufficiently strong to scatter electrons, raising the plasma's local resistivity. This would allow the magnetic flux to diffuse faster.>>

[MarkBour]

A current problem in plasma physics is that observed reconnection happens much faster than predicted by MHD in high Lundquist number plasmas (i.e. fast magnetic reconnection). Solar flares, for example, proceed 13–14 orders of magnitude faster than a naive calculation would suggest, and several orders of magnitude faster than current theoretical models that include turbulence and kinetic effects. One possible mechanism to explain the discrepancy is that the electromagnetic turbulence in the boundary layer is sufficiently strong to scatter electrons, raising the plasma's local resistivity. This would allow the magnetic flux to diffuse faster.>>

13-14 orders of magnitude? Probably just a round-off error.

[johnnydeep]

The surface gravity on the sun is 28 times greater than our surface gravity, here on Earth.
Yet the sun is able on a daily basis to blast flares having mass 1.6 X 10^12 kg (3.5 ≈ 10^12 lb) out into the solar system and beyond.
How does it do this? It's magnetic field. Which is only 1 Gauss. Earth's is ~0.5 Gauss.
I guess the difference is that the sun is completely gaseous, so sunspots can form with magnetic field 1000 to 2000 gauss.
I'm still utterly amazed that so much mass can be launched!
Makes NASA look like a pitiful weakling!

I'll add to neufer's post by citing this bit stating that the local magnetic field strength can be thousands of times larger than the average strength:

The Sun's Magnetic Field
The Sun has a very large and very complex magnetic field. The magnetic field at an average place on the Sun is around 1 Gauss, about twice as strong as the average field on the surface of Earth (around 0.5 Gauss). Since the Sun's surface is more than 12,000 times larger than Earth's, the overall influence of the Sun's magnetic field is vast.

The magnetic field of the Sun actually extends far out into space, beyond the furthest planet (Pluto). This distant extension of the Sun's magnetic field is called the Interplanetary Magnetic Field (IMF). The solar wind, the stream of charged particles that flows outward from the Sun, carries the IMF to the planets and beyond. The solar wind and IMF interact with planetary magnetic fields in complex ways, generating phenomena such as the aurora.

Overall, the basic shape of the Sun's magnetic field is like the shape of Earth's field... or like the field of a simple bar magnet. However, superimposed on this basic field (called a dipole field) is a much more complex series of local fields that vary over time. Places where the Sun's magnetic field is especially strong are called active regions, and often produce telltale sunspots. The local magnetic field in the neighborhood of a large sunspot can be as strong as 4,000 Gauss... much, much greater than the Sun's average field. Disruptions in magnetic fields near active regions can spawn energetic explosions on the Sun such as solar flares and Coronal Mass Ejections. The degree of complexity of the Sun's field waxes and wanes over the course of each sunspot cycle.

No doubt the concentrating of the magnetic field is due to the "twisting" that neufer described. I guess the Earth's magnetic field barely gets twisted at all...or does the rotation of the molten iron core have a twisting effect?

[neufer]

I'm still utterly amazed that so much mass can be launched!

Makes NASA look like a pitiful weakling!

NASA could produce Corona Mass Injections (CMIs) if it weren't for
Nicki Minaj's tweet about her unidentified cousin’s friend in Trinidad.

[neufer]

Click to play embedded YouTube video.

No doubt the concentrating of the magnetic field is due to the "twisting" that neufer described. I guess the Earth's magnetic field barely gets twisted at all...or does the rotation of the molten iron core have a twisting effect?

[Fred the Cat]

I'm still utterly amazed that so much mass can be launched!

Makes NASA look like a pitiful weakling!

NASA could produce Corona Mass Injections (CMIs) if it weren't for
Nicki Minaj's tweet about her unidentified cousin’s friend in Trinidad.

She must have been sizing up binary red giants.

[Sa Ji Tario]

Generically, the waves on the ground were called earthquakes, those of the jet-ski and those of the air-jet atmosphere, the tsunami sounded better to the ear and that's how it was.

[Ann]

the link at missed our Earth is to https://www.bleachernation.com/wp-conte ... py-cat.jpg but yields:

Error 1011 Ray ID: 6aace38d18a661ee • 2021-11-08 06:54:14 UTC
Access denied
What happened?
The owner of this website (www.bleachernation.com) does not allow hotlinking to that resource (/wp-content/uploads/2012/12/relieved-happy-cat.jpg).

Click to view full size image

Lovely, Victor, but where did you find that cat?

Ann

[Ann]

I'm still utterly amazed that so much mass can be launched!

Makes NASA look like a pitiful weakling!

NASA could produce Corona Mass Injections (CMIs) if it weren't for
Nicki Minaj's tweet about her unidentified cousin’s friend in Trinidad.

She must have been sizing up binary red giants.

There is a Nicki Minaj joke here that I don't get (Nicki who? What tweet?), but I really appreciated the link to the fascinating tidbit about weighing binary red giants using astroseismology, Fred!

Ann

[Ann]

Thanks everyone, and particularly Art, for a fascinating read about Coronal Mass Ejections and the Sun's (and the Earth's) magnetic field.

Ann

[johnnydeep]

Click to play embedded YouTube video.

No doubt the concentrating of the magnetic field is due to the "twisting" that neufer described. I guess the Earth's magnetic field barely gets twisted at all...or does the rotation of the molten iron core have a twisting effect?

Is the implication of the video that a very strong CME impacting Earth's magnetic field can compress it significantly in places? If so, I wonder how much of a factor it can be strengthened by. Certainly not the 4000x factor that twisting of the Sun's magnetic field endures.

[neufer]

Is the implication of the video that a very strong CME impacting Earth's magnetic field can compress it significantly in places? If so, I wonder how much of a factor it can be strengthened by. Certainly not the 4000x factor that twisting of the Sun's magnetic field endures.

It only needs to compress it enough ("twist the magnetotail's compressed knickers") so that the northern & southern magnetotail lobes reconnect thru the central plasma sheet such that some blobs ("plasmoids") are mass injected back to Earth in the form of auroras:

<<A full understanding of the physical processes which lead to different types of auroras is still incomplete, but the basic cause involves the interaction of the solar wind with Earth's magnetosphere. The varying intensity of the solar wind produces effects of different magnitudes but includes one or more of the following physical scenarios.

Click to play embedded YouTube video.

2. Opposite the compressed [magnetosphere "bow shock"] is the magnetotail, where the magnetosphere extends far beyond the astronomical object. It contains two lobes, referred to as the northern and southern tail lobes. The tail lobes are almost empty, with few charged particles opposing the flow of the solar wind. The two lobes are separated by a plasma sheet, an area where the magnetic field is weaker, and the density of charged particles is higher.

Geomagnetic disturbance from an enhanced solar wind causes distortions of the magnetotail. These 'substorms' tend to occur after prolonged spells (on the order of hours) during which the interplanetary magnetic field has had an appreciable southward component. This leads to a higher rate of interconnection between its field lines and those of Earth. As a result, the solar wind moves magnetic flux (tubes of magnetic field lines, 'locked' together with their resident plasma) from the day side of Earth to the magnetotail, widening the obstacle it presents to the solar wind flow and constricting the tail on the night-side. Ultimately some tail plasma can separate ("magnetic reconnection"); some blobs ("plasmoids") are squeezed downstream and are carried away with the solar wind; others are squeezed toward Earth where their motion feeds strong outbursts of auroras, mainly around midnight ("unloading process"). A geomagnetic storm resulting from greater interaction adds many more particles to the plasma trapped around Earth, also producing enhancement of the "ring current". Occasionally the resulting modification of Earth's magnetic field can be so strong that it produces auroras visible at middle latitudes, on field lines much closer to the equator than those of the auroral zone.>>

[johnnydeep]

Is the implication of the video that a very strong CME impacting Earth's magnetic field can compress it significantly in places? If so, I wonder how much of a factor it can be strengthened by. Certainly not the 4000x factor that twisting of the Sun's magnetic field endures.

It only needs to compress it enough ("twist the magnetotail's compressed knickers") so that the northern & southern magnetotail lobes reconnect thru the central plasma sheet such that some blobs ("plasmoids") are mass injected back to Earth in the form of auroras:

<<A full understanding of the physical processes which lead to different types of auroras is still incomplete, but the basic cause involves the interaction of the solar wind with Earth's magnetosphere. The varying intensity of the solar wind produces effects of different magnitudes but includes one or more of the following physical scenarios.

Click to play embedded YouTube video.

2. Opposite the compressed [magnetosphere "bow shock"] is the magnetotail, where the magnetosphere extends far beyond the astronomical object. It contains two lobes, referred to as the northern and southern tail lobes. The tail lobes are almost empty, with few charged particles opposing the flow of the solar wind. The two lobes are separated by a plasma sheet, an area where the magnetic field is weaker, and the density of charged particles is higher.

Geomagnetic disturbance from an enhanced solar wind causes distortions of the magnetotail. These 'substorms' tend to occur after prolonged spells (on the order of hours) during which the interplanetary magnetic field has had an appreciable southward component. This leads to a higher rate of interconnection between its field lines and those of Earth. As a result, the solar wind moves magnetic flux (tubes of magnetic field lines, 'locked' together with their resident plasma) from the day side of Earth to the magnetotail, widening the obstacle it presents to the solar wind flow and constricting the tail on the night-side. Ultimately some tail plasma can separate ("magnetic reconnection"); some blobs ("plasmoids") are squeezed downstream and are carried away with the solar wind; others are squeezed toward Earth where their motion feeds strong outbursts of auroras, mainly around midnight ("unloading process"). A geomagnetic storm resulting from greater interaction adds many more particles to the plasma trapped around Earth, also producing enhancement of the "ring current". Occasionally the resulting modification of Earth's magnetic field can be so strong that it produces auroras visible at middle latitudes, on field lines much closer to the equator than those of the auroral zone.>>

Thanks. The short video seemed clear. The words, less so. It's still unclear to me though how much twisting of the Earth's magnetic field occurs, either due to the fluid core dynamics or perhaps other causes. But I do know that the processes are not exactly simple, since the field completely reverses every so often.

[VictorBorun]

Lovely, Victor, but where did you find that cat?
Ann

APOD posted a hyperlink to a site that disallows hyperlinking.
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