I really love those fade in-fade out pics.  Really drives the points home.  

1 minute ago, hamateur 1953 said:

I really love those fade in-fade out pics.  Really drives the points home.  

I really want to learn how to make them as well. I think I have all the software and hardware just need the knowledge!

9 minutes ago, hamateur 1953 said:

I really love those fade in-fade out pics.  Really drives the points home.  

6 minutes ago, Parabolic said:

I really want to learn how to make them as well. I think I have all the software and hardware just need the knowledge!

To begin with I just used this service; simply choose two files (in this case the same area cropped from both i-gram and m-gram) and toggle on the "crossfade frames" option. With the default delays it'll look a bit off though, and possibly induce an epileptic seizure, but if you set the "Delay" for each of the images to 100 (each unit being 10 ms, so 100 would be 1 second), the "Fader delay" to 10, and the "Frame count" to 20, it'll look almost exactly the same as the one I posted above.

It can be a bit tedious and time-consuming to manually crop the images (I used this, since you can easily see which area you specify there, so that you can do it for both) and go through the above process though, so I ended up automating it personally, but that's more work. I'd be happy to help do it though, but probably better to do so by message in that case.

52 minutes ago, Philalethes said:

I'd be happy to help do it though, but probably better to do so by message in that case.

That would be greatly appreciated!

Crazy how this region hasn’t popped yet. Those deltas are strong and the umbras are practically touching.

28 minutes ago, Miles said:

Crazy how this region hasn’t popped yet. Those deltas are strong and the umbras are practically touching.

Someone created a meme explaining this anomaly recently I think. 🤣🤣

The shear in the area I circled should be really intense. I'm hoping it will start flaring in the next 12-24 hours.

@Jesterface23 is the red inside the hole within the blue an artifact? I think i saw that with other strong sunspots with "holes" in hmi 

1 minute ago, Parabolic said:

The shear in the area I circled should be really intense. I'm hoping it will start flaring in the next 12-24 hours.

thanks for the update  Do you have any idea about the red in the blue?

2 minutes ago, MinYoongi said:

@Jesterface23 is the red inside the hole within the blue an artifact?

I think so too. I remember at least one sunspot (last year, if I'm not mistaken) where the same thing happened.

Just now, Ester89 said:

I think so too. I remember at least one sunspot (last year, if I'm not mistaken) where the same thing happened.

thanks for confirming. sometimes i dont know if i genuinly remember or not.

7 hours ago, MinYoongi said:

May i ask why you doubt it? Sometimes i get frustrated with my own "ability" to evaluate regions, so i ask for opinions on others and how they form them so i can get a better and differenciated look at things.

 

btw: Ive seen comparing my imagery from this morning and now, that the leading spot got less intense in blue color and the negative got less intense in red colour. does that essentially mean the umbra itself got magnetically a bit weaker since the colour intensity depicts strength?

I don’t know about anybody’s assumption of anything because I’ve seen in the archives of old, massive solar, flares. They come from some of the most active regions, but when they were in an infant stage, according to the dates in the corresponding dates, it seems that any flare at any time can come from any type of spot I don’t know that’s just what I’ve come to see.

8 minutes ago, ScrapFatherScrapSon said:

I don’t know about anybody’s assumption of anything because I’ve seen in the archives of old, massive solar, flares. They come from some of the most active regions, but when they were in an infant stage, according to the dates in the corresponding dates, it seems that any flare at any time can come from any type of spot I don’t know that’s just what I’ve come to see.

A very good point. Although rare we have seen flares erupt from plage areas.  Marcel and some of our more experienced members seem to know what to expect from a given configuration though.  I also check STAR. ( Jan Alvestad’s site) daily when things get hectic.  

9 minutes ago, ScrapFatherScrapSon said:

it seems that any flare at any time can come from any type of spot

Well, that's a bit exaggerated, but it's certainly true that regions which end up being highly active and complex can flare while still in their infancy, so that it seems like the flare is coming from a region that's not very complex, but it's not that common. And of course occasionally big flares seem to come out of nowhere from regions that don't really end up developing much complexity either, but that's even less common.

So while you might technically be correct (at least up to a certain extent, as the very strongest flares almost always tend to come from regions that are already complex), there's definitely a relationship between complexity and productivity in terms of flares and CMEs; usually they go with each other.

I also look at solar soft for increasing activity on recent regions. This seems helpful to me at least.  

Im still puzzled about the Magnetogram.  

Can someone tell me where to look for the black and white version? I just don’t know what to think anymore about this artifact 

44 minutes ago, MinYoongi said:

Im still puzzled about the Magnetogram.  

Can someone tell me where to look for the black and white version? I just don’t know what to think anymore about this artifact 

This interested me as well. Since SDO's magnetograms work by observing the line splitting at a certain bandpass using a doppler imager (if I remember correctly).. maybe the velocities at the center of the umbra are high enough to mess up the readings due to the doppler effect? Just thinking about those animated gifs of sunspots showing material falling into the umbra - there must be pretty high velocities there.

Edited August 13, 20241 yr by thierry

54 minutes ago, MinYoongi said:

Can someone tell me where to look for the black and white version?

It's on the SDO data page; the artifact is present there too though, heh.

7 minutes ago, Philalethes said:

It's on the SDO data page; the artifact is present there too though, heh.

I guess its because its derived from the same data, right? after all its just the non colourized version of the HMI pictures i use.

Do you think its an artifact? I checked my screenshots from last night, there was already a red spot/encirclement going on exactly there.

Edited August 13, 20241 yr by MinYoongi

You’d think it’ll have to flare sometime soon. It’s got a crazy strong magnetic field and very tight deltas. 

37 minutes ago, MinYoongi said:

I guess its because its derived from the same data, right? after all its just the non colourized version of the HMI pictures i use.

Do you think its an artifact? I checked my screenshots from last night, there was already a red spot/encirclement going on exactly there.

Yep, it's ultimately the same imagery indeed. And yeah, I'm pretty sure it's an artifact. If I remember correctly someone (@Jesterface23?) had asked someone at NASA about it and gotten a clear confirmation that those are known artifacts, but I can't recall the details.

1 hour ago, thierry said:

This interested me as well. Since SDO's magnetograms work by observing the line splitting at a certain bandpass using a doppler imager (if I remember correctly).. maybe the velocities at the center of the umbra are high enough to mess up the readings due to the doppler effect? Just thinking about those animated gifs of sunspots showing material falling into the umbra - there must be pretty high velocities there.

It's not really measuring any movement directly; as you say it's measuring line splitting (Zeeman effect), and also the polarization of the light, but ultimately it's all derived from the strength of the magnetic field there. But it's probably correct that it's due to the strength of the field being so high there that it messes up the readings somewhat. I don't know for sure what the reason is, though.

1 minute ago, Philalethes said:

Yep, it's ultimately the same imagery indeed. And yeah, I'm pretty sure it's an artifact. If I remember correctly someone (@Jesterface23?) had asked someone at NASA about it and gotten a clear confirmation that those are known artifacts, but I can't recall the details.

It's not really measuring any movement directly; as you say it's measuring line splitting (Zeeman effect), and also the polarization of the light, but ultimately it's all derived from the strength of the magnetic field there. But it's probably correct that it's due to the strength of the field being so high there that it messes up the readings somewhat. I don't know for sure what the reason is, though.

Thank you, i already remembered that but wasnt sure it really happened! lol

1 hour ago, Philalethes said:

Yep, it's ultimately the same imagery indeed. And yeah, I'm pretty sure it's an artifact. It's not really measuring any movement directly; as you say it's measuring line splitting (Zeeman effect), and also the polarization of the light, but ultimately it's all derived from the strength of the magnetic field there. But it's probably correct that it's due to the strength of the field being so high there that it messes up the readings somewhat. I don't know for sure what the reason is, though.

I found the original post here

 

Edited August 13, 20241 yr by Parabolic
Found original post, deleted my comment

48 minutes ago, Philalethes said:

as you say it's measuring line splitting (Zeeman effect), and also the polarization of the light, but ultimately it's all derived from the strength of the magnetic field there. But it's probably correct that it's due to the strength of the field being so high there that it messes up the readings somewhat. I don't know for sure what the reason is, though.

I see, that would probably make more sense 😅.

Quote

It's not really measuring any movement directly

True, though I wasn't under the impression that it measured movement, I was more thinking about the principle of measuring Zeeman splitting. Spectral lines broaden if the emitting particles have a distribution of high velocities; Surely that would affect measurements for Zeeman splitting since you need to analyse spectral lines in order to do so? 

Edited August 13, 20241 yr by thierry

24 minutes ago, thierry said:

True, though I wasn't under the impression that it measured movement, I was more thinking about the principle of measuring Zeeman splitting. Spectral lines broaden if the emitting particles have a distribution of high velocities; Surely that would affect measurements for Zeeman splitting since you need to analyse spectral lines in order to do so? 

I assume you're referring to Doppler broadening. You're certainly right that this has to be accounted for; as this paper states:

Quote

The values of the derived field strengths are sensitive to the amount of Doppler broadening assumed (which is generally larger than in the external atmosphere), since the non-linearities scale with the ratio between the Zeeman splitting and the Doppler width.

However, from what I've gathered this can be separated out with a neat "trick", as the paper goes on to explain:

Quote

 

A field-strength distribution gives rise to Zeeman line broadening, which becomes prominent in the infrared due to the wavelength dependence of the Zeeman splitting. The problem is however that the nonthermal Doppler broadening inside the fluxtubes is significantly larger than in the external atmosphere, and contributes to the broadening of the Stokes V profiles. The trick to separate the effects of Doppler and Zeeman broadening from each other is to use a kind of "infrared line ratio", with two lines having greatly different Zeeman sensitivities. This is illustrated in Fig. 7, from Zayer et al. (1989). The Stokes V profiles (solid curves) in a network element at disk center for the two Fe I lines at 15 648.54 Å (Landé factor 3.0) and 15 822.81 Å (Landé factor 0.75) are displayed and compared with the corresponding profiles predicted with the assumption of a single-valued field (dashed curves). The two lines have practically the same excitation potential of the lower atomic level (5.43 and 5.64 eV, respectively) and similar line strengths, and are therefore formed at almost the same height in the atmosphere. Due to the small Landé factor of the second line (the "Doppler line"), Zeeman broadening is insignificant as compared with the Doppler broadening, whereas the first line (the "Zeeman line") is quite strongly Zeeman broadened.

Fig. 7 shows that when no field-strength distribution is introduced, and the Doppler broadening is adjusted to fit the width of the "Zeeman" line, then the predicted width of the "Doppler" line is too large (upper portion of Fig. 7). When on the other hand the Doppler broadening is adjusted to fit the Doppler line, then the predicted width of the Zeeman line is much too small. This clearly demonstrates that Zeeman broadening due to a field-strength distribution must be invoked to explain the observed profiles.

And here's Fig. 7 referred to for reference:

Based on this I don't think that's ultimately what's causing the artifact in question, but I'm by no means certain. I guess we'd ideally get an answer from someone with intimate knowledge of HMI and its operation, and know might know exactly what the cause of the artifact is, beyond just knowing that it is one.

Parabolic also just bumped the thread with the post I was referring to earlier (indeed by Jesterface). From what it's saying it's not something that has to do with the HMI measurements themselves, but something to do with the algorithm being used for the real-time data on the SDO data page. Then again, maybe the proper algorithm is accounting for something about the measurements that is relevant. Hard to say unless we might get an answer to what about the algorithm is causing it.

I guess it would be best to take further discussion about this artifact and similar ones to that thread.

2 minutes ago, Philalethes said:

I assume you're referring to Doppler broadening. You're certainly right that this has to be accounted for; as this paper states:

However, from what I've gathered this can be separated out with a neat "trick", as the paper goes on to explain:

And here's Fig. 7 referred to for reference:

Based on this I don't think that's ultimately what's causing the artifact in question, but I'm by no means certain. I guess we'd ideally get an answer from someone with intimate knowledge of HMI and its operation, and know might know exactly what the cause of the artifact is, beyond just knowing that it is one.

That is a very neat trick indeed! Hopefully we'll get some more info soon on the artifact.