Split sun pillar, Taivaanvahti (Inari / Finland, 12.11.2021)

[Timo Kuhmonen]

I have not seen similar like this before... Any ideas what could cause splitting of pillar?
https://www.taivaanvahti.fi/observations/show/102316

In practise it may be possible, that in the middle of sun disk there is dense cloud blocking sunrays? Would be practical reason ? Also the sun is not a point source of light, approx 0.5 degrees wide.

Another thing came into mind, distribution of ice crystals. Can it be so "sharp" that one pillar could have a "dark band" in the middle - personnally for me it is difficult to explain by this method...

[Elmar Schmidt]

Me neither, Timo,

I read in the Finnish comments, that the photo was taken with a 200 mm lens. If in full-format, the distance of the pillars would be 0.47 degrees. This is a bit large IMO, to be explained by a very dark object (cloud) covering the sun's middle section so as not to contribute to this pillar.

A trivial explanation would be, that the image was cropped or the lens was used with an APS or even smaller sensor.

An exotic explanation would require two collectives of ice crystals with slightly different angles of their horizontal faces, but I hold this to be unlikely, as then there should be an angle between the two pillars too.

Kind regards

Elmar

[Christoph Gerber]

The picture reminds me of a double pillar at Venus and Jupiter in conjunction I had photographed many many years ago. My interpretation of the scenario would be the following:
1. the sun ist seen through a very thin slit/slot in a (low) cloud cover
2. there are further small clouds (at higher altitudes) that can be seen through this slit.
3. I guess that one of this small clouds was in front of the solar disc, and thus only the two rims of the sun were bright enough to produce a pillar – that is why we see two pillars.
It is a pity that the second picture mentioned (showing only one pillar) is not shown. I guess that on this picture the pillar should be as broad as the two pillars in this picture (the 0.5° mentioned by Elmar – which corresponds to the apparent diameter of the sun). Then the split pillar should have been only a chance alignment for a few seconds – in agreement with the statments "one hurried shot" ... "the following picture".

Best regards,
Christoph