The Halo Vault

The Finnish Astronomical Association URSA has just published a new book on halos by Marko Riikonen. This book combines the latest halo scien...

I wish you all a very happy year 2011, may it be rich in halos and celestial wonders! I ran some simulation of halos created by hollow colum...

Here is an observation suggestion for next winter. Marko Mikkilä photographed possible new arcs during winter 2007-2008 ( 1 ). Source eleva...

Here are some simulations to follow up with the possible new arc from Moilanen crystals ( 1 ). As suggested by Marko, I did some “photo qu...

For quite a long time I was wondering how halos in nearby ice crystals, especially when caused by divergent light, are perceived spatially. ...

In numerous entries of this blog there are halo simulations made with "a simulation software by Jukka Ruoskanen". The software has...

I expanded the "Forked Pillars and Helic Arcs" article. As before, it is on my page ( 1 ). For observers probably the most intrig...

The halo application simulates streetlight halos ( 1 ). It can handle plate and column crystals as well as Parry oriented crystals. It can ...

The days are shortening and winter is coming soon. What a better way to get pumped for the upcoming diamond dust season than reading Walt Ta...

There is less than half a year left until Halo Meeting 2009. The "official" registration form ( 1 ) has been added to our websit...

Streetlamp halos with their spatial form can be memorable experiences for the viewer. Yet, we know rather little of them. But now this is ch...

The subhorizon photos of 7/8 December show what seems to be part of a diffuse circular halo surrounding the subanthelic point. Similar effe...

What happens when tilts of the crystals that make blue spot increase? The blue spot starts to elongate vertically, forming eventually a blu...

The photo is from last weekends major display. The arrow in the accompanying simulation (Jukka Ruoskanen's program) points to a halo th...

On the night of 7/8 December in Rovaniemi water fog was nucleated to diamond dust by snow machines, and a major display was observed in a s...

To supplement Les's posting, here is the behaviour of the reflected Parry as a function of sun elevation. At sun elevations higher than...

In the image on the left is Moilanen arc among other halos. On the right is similar looking halo (arrow), but its V is more pointed and it ...

For the very lowest sun elevations there are only two photos, both shown here. Four uppermost images are versions of the same photo, which ...

Now the sun elevation at Lascar is 2-3 degrees. The image is four frame stack. 20° upper plate arc is well visible. New feature, "Moil...

Continuing the Lascar halos tour. This image gives situation for sun elevation range of 11° to 9°. Image is stacked from four photos and als...