10 October 2024 Auroras

Several days earlier sunspot AR3842 exploded into flares producing several large CMEs. These arrived on 10 October and created a G4-G5 geomagnetic storm that produced intense auroras as far south as Mexico. The auroras persisted all evening (see video below), but three times burst into visually very bright displays of red and green pillars. Spectacular!

Looking north at 19:20. This was still evening twilight, so the blue sky and the red aurora mix to produce a purple sky. 5-second exposure, Canon 7D, ISO 1600, 14mm lens.

Looking north at 20:11. 5-second exposure, Canon 7D, ISO 1600, 14mm lens.

Looking north at 20:13. 5-second exposure, Canon 7D, ISO 1600, 14mm lens.

Single frame from a fisheye video allsky camera at 20:35. Note the interesting bright red band extending across the sky just south of the zenith. This may not be aurora at all, but an example of a SAR, a Stable Auroral Arc. Despite the name, these are not auroras (which are caused by charged particles raining down on the atmosphere and causing gases to glow), but are related to a donut-shaped ring around the Earth that conducts a huge electric current. 5-second exposure, north up, east left.

Phone camera image looking west at 20:42. Visible is the bright streak of red (SAR?) seen extending across the sky in the above allsky image. Pixel 9 Pro image, 0.35s exposure, 24mm focal length equivalent.

Looking north at 22:41. 10-second exposure, Canon 7D, ISO 1600, 14mm lens.

Looking north at 01:29. 10-second exposure, Canon 7D, ISO 1600, 14mm lens.

An animated sequence of 15-second frames spanning 10 hours, from dusk until dawn.