Half-sky auroras - 17.8.2022 at 23.15 - 18.8.2022 at 00.30 Laitila Observation number 110829

Copyright © 2022 Pirjo Koski. All rights reserved.

Visibility III / V

Pirjo Koski, Porin Karhunvartijat

This summer aurora gig turned out to be really challenging in terms of shape recognition. At that time, it was reasonably bright at night, and on top of that, a more or less full Moon seemed to climb into the sky during the filming.

At night, maybe Steve etc. was seen on some aurora camera, because the undersigned got a call from Matias (thank you) on his cell phone in the middle of everything "look for Steve in the sky, there might be something there".

The eye could see a slender pillar like Steve's, or a torch. It was really hard to say anything even on the spot, because there was so much other light. Abundant Cloudiness also hindered observation quite significantly.

In any case, the northern lights were above the zenith at best. I wondered about the aurora belt, which was quite thin and passed overhead, for that my location could very well have been in Finnish Lapland, but this time we were firmly on the West Coast, almost on the Pyhäranta side. I haven't seen an awful lot of times in the south such a flattened, westward curve.

A corona didn't form right away either, but the band twisted and lived slowly in the sky. Korona was the last to emerge into the moonlit night sky.

An incredible night with the temperature vs. experienced. Scorching 20 degrees of heat through the night and more than half the sky repos. Pretty tough stuff.

But oh council of honor, please help the woman in identifying these shapes, please :)

This description has been automatically translated from Finnish. Click here to see the original text.

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Additional information

Aurora brightness
- Dim auroras
Observed aurora forms
- Arc
  
  ARC The arcs are wider than the bands and do not fold as strongly. The arcs are normally neither very bright nor active.
  
  The arc is probably the most common form of aurora. When aurora show is a calm arc in the low northern sky it often doesn’t evolve to anything more during night. In more active shows the arc is often the first form to appear and the last to disappear.
  
  The lower edge of the arc is usually sharp but the upper edge can gradually blend into the background sky. As activity increases rays and folds normally develop, and the arcs turn gradually into bands.
  
  An aurora arc runs across the picture. Vertical shapes are rays. Photo by Atacan Ergin.
  
  Aurora Arc. Photo by Mauri Korpi.
  
  Aurora Arc. Photo by Anna-Liisa Sarajärvi.
  
  Aurora Arc. Photo by Matti Asumalahti.
- Corona
  
  CoronaA corona is a hand fan shaped structure, it usually forms south of the observer's zenith, most commonly consisting of rays or bands. The corona is usually the most beautiful part of the aurora show. It is bright and active, but on the other hand also short-lived.
  
  Aurora corona. Photo by Anna-Liisa Sarajärvi.
  
  Aurora corona. Photo by Merja Ruotsalainen.
  
  Corona formed from bands. Photo by Markku Ruonala.
  
  Aurora corona. Photo by Tapio Koski.
- Band
  
  Bands are usually narrower, more twisty at the bottom, brighter, and more active than arches. Bands usually develop from arches.
  
  Bands can form J and U shapes, sometimes even full spirals. The corona can also arise from bands. Bands are a fairly common form of aurora.
  
  Aurora band. Photo by Merja Ruotsalainen.
  
  Aurora band. Photo by Matias Takala.
  
  Aurora band. Photo by Lea Rahtu-Korpela.
  
  Aurora bands. Photo by Lauri Koivuluoma.
  
  Aurora band. Photo by Matias Takala.
- Rays
  
  The raysare parallel to the lines of force of the magnetic field, i.e. quite vertical, usually less than one degree thick light streaks. The rays can occur alone or in connection with other shapes, mainly with arcs and bands. Short rays are usually brightest at the bottom but dim quickly. The longest rays, even extending almost from the horizon to the zenith, are usually uniformly bright and quite calm, and unlike the shorter rays, most often occur in groups of a few rays or alone. Rays, like bands, are a very typical form of aurora.
  
  Artificial light pillars, which are a halo phenomenon visible in ice mist, can sometimes be very similar to the rays of aurora. Confusion is possible especially when the lamps that cause the artificial light pillars are far away and not visible behind buildings or the forest. The nature of the phenomenon is clear at least from the photographs.
  
  Rays. Picture of Tom Eklund.
  
  Rays. Photo by Mika Puurula.
  
  Two beams rise from the aurora veil. Photo by Anssi Mäntylä.
  
  Two radial bands. Show Jani Lauanne.
  
  Radial band and veil. Photo by Jussi Alanenpää.
  
  Two rays. Photo by Aki Taavitsainen.
  
  It may be possible to confuse such rays with artificial light columns. Compare the image below. Picture of Tom Eklund.
  
  There is no aurora in this image, but all the light poles - including the wide and diffuse bar seen at the top left - are artificial light pillars born of ice mist. Photo by Sami Jumppanen.
  
  Aurora and artificial light pillars. All the radial shapes in the picture above are probably artificial light pillars that coincide appropriately with the aurora band. In the image below, the aurora band has shifted and does not overlap with the pillars produced by the orange bulbs. There is no orange in auroras. Photo by Katariina Roiha
- Veil
  
  Veil
  Veil is the most bland and very common form of aurora. It usually covers its homogeneous dim glow over a wide area of the sky at once. Most often, the veil is seen in the calmer and quiet phase of the night after the aurora maximum as a background for other forms. The veil can also occur alone and in that case it will be quite difficult to reliably identify as an aurora, especially at a observation site which has a lot of light pollution.
  
  A similar glow of light can also be caused by airborne moisture, smoke, or a very thin layer of clouds that reflects the light that hits them. However, clouds can also be used to identify veil, especially if the middle or upper cloud appears dark against a lighter background, then it is very likely to be aurora veil if the brightness of the background sky is not due to the rising or falling Moon or Sun. When photographing, very long exposure times usually reveal the green colour of the veil auroras.
  
  Veil and rays. Photo by Esa Palmi.
  
  Red aurora veil. Photo by Marko Mikkilä.
  
  Veil. Photo by Milla Myllymaa.
  
  Aurora veil that changes color from green at the lower edge through purple to blue at the top. Photo by Jaakko Hatanpää.
  
  Dim green veil. Photo by Jarmo Leskinen.
  
  Radial aurora band surrounded by veil. Photo by Jussi Alanenpää.
- Pulsating patches
  
  Pulsating patches or -aurora typically have more or less regular shape and size. They typically appear in the later part of an aurora display. They are almost always pulsating in variable periods.
- Form not identifiable
  
  Form not identifiable
  Sometimes auroras have to be observed in such poor conditions that it is not possible to reliably identify the shape even if for example the structure and conditions could be recognized. Such a situation could be the outcome of for example alight background sky, cloud cover or a covered horizon.

Technical information

Canon EOS 6D, Irix Blackstone 15mm

ISO 800-1600, f2.5-3.5, 3-10s

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