Contact information

Skywarden,
Ursa Astronomical Association
Kopernikuksentie 1
00130 Helsinki
taivaanvahti(at)ursa.fi

Ursa Astronomical Association

Quiet aurora arc - 29.9.2021 at 23.06 - 29.9.2021 at 23.50 Enontekiö Observation number 101637

Visibility II / V


Initially, among the clouds illuminated by the moon, a gauze stood out faintly, the greenery of which appeared in the photograph. As the air cleared, a cloudy arc settled in the sky, which brightened and dimmed in the elevator. There was also brighter material among the clouds on the northern horizon.



More similar observations
Additional information
  • Aurora brightness
    • Dim auroras
  • Observed aurora forms
    • Arc info

      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.

Send a comment

Comments are checked and moderated before publication If you want to contact the observer directly about possibilities to use these images, use the Media -form.

*

*

*
characters left

By sending in this comment I confirm, that I've read and understood the the observation system's privacy policy.