7 hours ago, Alphane said:

I'm not as educated as you in the subject but was proposing a possible solution to the effect mentioned .

I imagine the aura as a fog being it's formed by stimulation of gas particles therefore looking through a fog of enlightened materials might effect the brightness of objects behind . Positively possibly .

Not sure wether the book mentioned is fiction and if the effect mentioned is actually truly observable in the real world . If so surely additive filtration is the explanation or at least I imagine so or would you propose some other possible explanation ? Or do you believe this is just a fictional scenario created by the writer ?

/Edit

After doing some searching I managed to find this image .

There doesn't appear to be more stars in the enlightened area but especially in the green area just left and below centre the stars certainly appear to be coloured by the aurora . Can also be seen more subtly in the pink areas. This effect is what I was trying to describe with my ' filter ' analogy . I would also agree with you though the brighter area of the aurora occlude the stars behind .

I definitely agree that the aurora could make the stars look tinted a different color. However, the aurora as a “luminescent fog” cannot enhance the brightness of anything behind it. It would require energy to amplify the light, which we do not see here. Besides, imagine if this was true, all we would need to do see dim stuff in space or on Earth would be shine a big light at the sky, and we can easily see that is not the case. Aurora is no different than light pollution as far as this is concerned.

The book in question appears to be nonfiction, I’ve read it I think, I remember it being interesting. However, it’s not really about astronomy, and sounds like the quote is referencing a different person’s anecdotal experience. I do not think it in any way constitutes a scientific source.

I realize we have reached our solar max, but a couple questions:

1. How long after max will auroras still be visible at mid lats?

2. After 2026 will they still be visible on occasion?

I don't want to have to give up this hobby in a few years 🤩

15 hours ago, Alphane said:

I'm not as educated as you in the subject but was proposing a possible solution to the effect mentioned .

I imagine the aura as a fog being it's formed by stimulation of gas particles therefore looking through a fog of enlightened materials might effect the brightness of objects behind . Positively possibly .

Not sure wether the book mentioned is fiction and if the effect mentioned is actually truly observable in the real world . If so surely additive filtration is the explanation or at least I imagine so or would you propose some other possible explanation ? Or do you believe this is just a fictional scenario created by the writer ?

/Edit

After doing some searching I managed to find this image .

There doesn't appear to be more stars in the enlightened area but especially in the green area just left and below centre the stars certainly appear to be coloured by the aurora . Can also be seen more subtly in the pink areas. This effect is what I was trying to describe with my ' filter ' analogy . I would also agree with you though the brighter area of the aurora occlude the stars behind .

Alphane: Thank you for working on this topic and I am glad you found it at least interesting. The book is nonfiction and is mostly, as the name "Underland" implies, about caving and plants, Macfarlane's specialties. So although he is not a sky-watching expert, as a naturalist I would say he is very good at taking notes, which is why I paid attention to this. If no one else sees this phenomenon, of stars showing brighter behind an aurora, then there was another reason, such as he was tired from a long day of exploring ice caves in Greenland!

My notion was that the stars might look different if seen through green auroras rather than red auroras for the same reason that you use red or amber flashlights and not other colored light when under the night sky so as not to disturb your night vision. I have not seen an aurora bright enough for the light of the aurora to have an effect on night vision, but I have only seen "low latitude" auroras, which is why I asked if those blessed with "real" high latitude auroras had seen this effect. Many of the "live" aurora cameras available online are placed in sites that have significant city light pollution, but the auroras can still be seen, meaning that they are bright enough to see even without dark sky adapted vision. Maybe they are sometimes bright enough to have an influence on night vision. So, the effect in this case would be on the eyes of the observer, what the person saw with their eyes, not the observed scene; a photo of the sky would not answer this question.

Your additive filter idea seems appropriate as well. The effect could be similar to the enhancement of faint nebulas seen in a telescope through light polluted skies, with an appropriate filter on a telescope eyepiece.

None of the aurora enthusiasts who responded to my post saw what Macfarlane saw, so the conclusion seems obvious at this point.

22 hours ago, LightChaser said:

I realize we have reached our solar max, but a couple questions:

1. How long after max will auroras still be visible at mid lats?

2. After 2026 will they still be visible on occasion?

I don't want to have to give up this hobby in a few years 🤩

Definitely a concern for us these days! 😅
We should have several more years of chances of good storms, it's a long time before minimum.
And even during Solar Min, the Coronal Holes come back (like we have seen recently), and these can give some decent storms too!
Hang in there!

In the lasso coronagraph image, is the top of the disk the far side of the sun?

Just now, stargazer007 said:

In the lasso coronagraph image, is the top of the disk the far side of the sun?

Did you not ask it already before? It is almost the same perspective as from Earth. Farside is behind the sun. Top is north, bottom is south, left is east and right is west. You are giving a Blindsight impression again.

On 2/21/2025 at 7:33 AM, LightChaser said:

I realize we have reached our solar max, but a couple questions:

1. How long after max will auroras still be visible at mid lats?

2. After 2026 will they still be visible on occasion?

I don't want to have to give up this hobby in a few years 🤩

Here's an updated version of this plot, with up-to-date flare data that I recently compiled; as you can see geomagnetic activity generally peaks after SSN maximum, so hopefully we'll see something similar for this cycle:

Edited February 22Feb 22 by Philalethes
embedding

I do find the length of time since we had a G4/G5 a bit odd given where we stand in the SC and the SC’s overall decent strength

1 hour ago, Sam Warfel said:

I do find the length of time since we had a G4/G5 a bit odd given where we stand in the SC and the SC’s overall decent strength

Is there any chance that a G4 or G5 can be missed? I mean there are frequent data gaps and from what I've read on this forum, storms can be quite short lived. So it would stand to reason that they might occur "silently"... Or is this impossible?

6 minutes ago, Stella said:

Is there any chance that a G4 or G5 can be missed? I mean there are frequent data gaps and from what I've read on this forum, storms can be quite short lived. So it would stand to reason that they might occur "silently"... Or is this impossible?

Definitely would be impossible as these measurements are from ground based magnetometers from all over the globe that are averaged to create the Ap index.

4 minutes ago, Stella said:

Is there any chance that a G4 or G5 can be missed? I mean there are frequent data gaps and from what I've read on this forum, storms can be quite short lived. So it would stand to reason that they might occur "silently"... Or is this impossible?

I would say it would be pretty hard to miss a g4/g5 storm as we have multiple devices that can detect the values required to detect it, for weaker storms though it might be a possibility as once we had quite a visible aurora (lasted for about 10 minutes) but the values didn't seem to show that much activity but it could of been some other thing that caused it.

Would I be right in saying that density will increase the BT and then solar wind will drive all that into the poles?

9 hours ago, SearMr Cool said:

Would I be right in saying that density will increase the BT and then solar wind will drive all that into the poles?

Bt only reflects total magnetic field strength. I forget the actual equation but its a combination of bx, by, and bz. For the solar wind to enter the poles more easily you'll need either Southward bz or very abrupt fast wind (i.e. a shock front). Higher density will help strip back the magnetic field lines but its other role is to be injected into the ionsphere after entering through the poles.

58 minutes ago, Parabolic said:

I forget the actual equation but its a combination of bx, by, and bz.

It's Pythagoras in three dimensions, i.e.:

Bt² = Bx² + By² + Bz²

Or thus:

Bt = √(Bx² + By² + Bz²)

Where is the NASA solar orbiter satellite located in relation to earth?

1 minute ago, stargazer007 said:

Where is the NASA solar orbiter satellite located in relation to earth?

Maybe not the best method, but NASA WSA-Enlil models have some more interesting objects positioned. SolO is some 20 degrees behind us.

Just now, stargazer007 said:

Where is the NASA solar orbiter satellite located in relation to earth?

You can check the location here for future reference, shows the exact radius and heliocentric longitude relative to us. This image is the latest one as of writing this post:

6 minutes ago, MJOdorczuk said:

Maybe not the best method, but NASA WSA-Enlil models have some more interesting objects positioned. SolO is some 20 degrees behind us.

Where did you get that version of enlil from, I only found the one with earth and stereo a (https://www.swpc.noaa.gov/products/wsa-enlil-solar-wind-prediction)

1 minute ago, SpaceR said:

Where did you get that version of enlil from, I only found the one with earth and stereo a (https://www.swpc.noaa.gov/products/wsa-enlil-solar-wind-prediction)

https://kauai.ccmc.gsfc.nasa.gov/DONKI/ has a whole list of CMEs modelling. These are from NASA. What you linked is from NOAA.

Thanks.

Would an impact at solar orbiter have an effect on Earth?

3 minutes ago, stargazer007 said:

Would an impact at solar orbiter have an effect on Earth?

If SolO would be on the way, then whatever impacts SolO could potentially impact us. For that SolO would have to be a few degree ahead of us. Still, very short jump to 35 nT (or even more, assuming you mean that 70nT at SolO) would at best give us some G1, so maybe some nice auroras. If you want to see things that may impact Earth, look at L1 satellites like ACE or DSCOVR.

Is there a proton event associated with every stronger farside eruption or only some of them?

12 minutes ago, jensei said:

Is there a proton event associated with every stronger farside eruption or only some of them?

I would expect only those, that are close to the limb (and mainly the western) and align themselves well with the Parker Spiral.

(the time limit for writing posts is quite irritating. Understandable, but irritating nonetheless. I still have to wait three minutes as I write this)

Can a coronal hole have entirely north bz? Is it possible that this chhss will not dip into the negative or is that unlikely? This coronal hole will be earth facing during my time in Tromso next month, which is why I'm concerned