Sol (Sun) and its phenomena

[Olivierlejardinier]

There's still farside flaring, it will take about 8 days for AR4274 to return.

There was a full-halo CME this evening (UTC), apparently coming from a far side source. From the geometry of the CME it looks like the source region might be in the northern hemisphere, close to the far side central meridian - possibly 4274.

https://twitter.com/x/status/1992017874345673042

From spaceweather.com, 3I/ATLAS behaving like a normal comet, still discharging the solar capacitor:

INTERSTELLAR COMET 3I/ATLAS IN COLOR: Who needs satellites and space agencies? Using a backyard telescope on Earth, amateur astronomers Michael Jäger and Gerald Rhemann have just captured the best-yet color image of interstellar visitor 3I/ATLAS. It is unmistakably a comet.​

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With one exception (discussed below), the photo is "classic comet." The comet's long tail streams straight away from the sun, sculpted by solar wind. Its blue color comes from carbon monoxide ions, CO+, a compound found in almost all Solar System comets. The comet's head is green because of another common molecule, diatomic carbon (C2), which is released from icy comet cores when they get close to the sun.


Now for the exception: There is a jet poking out of 3I/ATLAS's head toward the sun. It stands out in this black-and-white image taken by Michael Jäger and Gerald Rhemann on Nov. 20th:

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[Gaby]

Auroras in the eastern hemisphere, thanks to a fast flow of plasma from a coronal flow.

Лаборатория солнечной астрономии (XRAS)

t.me

An intense aurora zone is forming over the country right now. Anyway, so far everyone here has been having fun with parodies of the coronal hole (Лаборатория солнечной астрономии (XRAS) ), a stream of plasma from it hit the Earth. Two days earlier than the forecast. Satellites record a rapid increase in the speed and temperature of the solar wind in the vicinity of the planet. There are no magnetic storms yet, but they usually develop with a delay of several hours. In the eastern hemisphere of the Earth, there is currently a rapid growth of the aurora zone, the lower boundary of which has descended in the last half hour to latitudes of about 55 degrees (Moscow, Kazan, Nizhny Novgorod).

The coronal hole at the moment, frankly speaking, has not yet reached those corners very much (https://xras.ru/database/sun_images/2025/aia211/202511/20251124_121757_aia211.jpg ), from which the wind flow was supposed to come to the Earth. This is approximately 50 degrees west (to the right) of the center of the visible disk. It is even surprising to look at the graphs in this regard, but the nature of measuring the velocity and density of gas leaves no doubt about the nature of the rapid flow that came to Earth: this is plasma born in a coronal hole. Let's see what happens next.

 

[Gaby]

For the second day in a row, Earth is receiving a fast stream of plasma from the sun, favoring auroras in certain regions. It's not very clear what is happening and why.

xras.ru

The Earth has been in the zone of action of the coronal solar hole for the second day.

For the second day, the planet passes through a rapid stream of plasma formed in a coronal hole in the Sun and unexpectedly, 2 days earlier than predicted, reached Earth yesterday. The hole itself is clearly visible in the images of the Sun and has a very unusual, highly indented shape, which makes it very difficult to understand what should be happening in interplanetary space and in what order.

In fact, very high wind speeds are recorded in the vicinity of the Earth (https://xras.ru/image/swv_RAL5_20251125.png ), 2 times higher than the norm, combined with fairly ordinary values of plasma density and magnetic field induction. This was enough to bring the Earth's magnetic field out of balance, but it was not enough for something more serious, which could have been if the plasma flow had been at least 3-4 times denser. As a result, the Kp index charts have turned noticeably yellow over the past day, but so far they have broken through the red level only once, and even then weakly: a short magnetic storm was observed around noon in Moscow today.

At the same time, geomagnetic activity had an unexpectedly strong effect on the intensity of the aurora borealis. Over the past 24 hours, their index has twice broken through the ceiling of the scale, equal to 10 (https://xras.ru/image/ai_RAL5_20251125.png ), but both times at a very bad time, especially today, when the next surge occurred exactly in the middle of the day in the central part of the country. In general, with very high wind speeds observed, the Earth's magnetosphere should respond quite violently to even small variations in the plasma flow, and bursts of auroras will almost certainly be repeated. Unfortunately, it is not so easy to find clear skies in the country at the moment, but some images of auroras are still being received: mainly from the northern and northwestern regions of the country.

The forecast for the duration of geomagnetic events is quite shot down due to their unexpectedly early start, but the hole does not look too big, and it seems that the yellow-red band on the charts will begin to crumble tomorrow morning, and by the end of the day the indices will completely return to the green zone. Flare activity is low at the moment — the star continues to recover from a series of X flares that occurred in the middle of the month. Somewhere on the far side of the Sun, the legendary region 4274, which actually raged here 10 days ago, is now trying to survive until it returns to Earth. Her return, if it takes place, is perhaps the main factor that will be able to turn the space weather picture upside down. Those active centers that are currently being observed on the Earth-facing side do not seem to be claiming anything serious yet.