Heidelberg (49°4 N, 8°7 E), April 6/7, 2000 (Times in CEST = UT +2h)
Here is the report on the aurora as it was visible from Heidelberg. It is quite detailed as it was the first aurora I observed that extended beyond a red glow over the northern horizon. I would not have thought it possible to experience such a complex northern lights display so far south. The detailed description may give those who did not observe the phenomenon and have not yet seen northern lights an impression of the sequence. As a "stargazer", I have naturally used the (abbreviated) constellation names quite often. Those who are not familiar with them are referred to the website www.heavens-above.com. Here, "Germany" and "Heidelberg" can be selected from the "site" database, and then the "whole sky chart" page can be chosen. There, the date and time (CEST, not UT!) can be entered, and the sky's appearance at the time of observation will be displayed. I hope this is a good guide.
Duration of the phenomenon: 23:00-3:00; apparently very rapid increase in activity to the "pre-maximum" around 22:55-23:05, interruption from about 0:00 to about 0:45(?), Maximum: 1:20-1:50, "post-maximum" 2:10-2:40, rapid end.
Starting just before 23:00 (returning home, but noticed nothing on the bike ride): In the north in CAS, a bright red glowing cloud with nearly vertical, about 10° high yellowish rays, another brightly glowing cloud in the NE in CYG. A red arc extended from about PER (in NW) across CAS, CEP to CYG (in NE). The phenomenon then decreased in intensity, especially the yellow rays; the red clouds in PER and CYG glimmered the longest. In the north, there was also a shallow "light dome" visible. The red clouds then became somewhat more intense again (23:10). (23:17) The light dome in the north was about 10° high and extended from about (Gamma) AND to Deneb (CYG), touching the horizon below Vega (LYR). About 10 minutes later, it was weaker but reached up to (Alpha) CAS (about 20° high). Then it collapsed again and brightened once more; it only protruded about 12(-15)° above the horizon (23:31). The height and intensity of the light dome fluctuated within this range until it almost completely faded around 0:00. The red cloud from CAS drifted slightly westward and then remained near the horizon in the PER/TAU area (in NNW). The entire extent of the light phenomenon reached up to Capella (AUR) and to CEP in the north, at 23:35, even reaching into GEM (WNW). Occasionally, briefly brighter rays were visible. All rays ran almost vertically (they were slightly inclined to the top left). At 23:36, the red glowing band extended from GEM over AUR (and above PER and CAS) to CEP. At 23:46, only a faint red glow could be seen. Around 0:00, the whole phenomenon seemed completely faded or ended, and I interrupted observation for a longer time.
(00:44) The light dome was visible again, stretching from about (Epsilon) PER in the NW to below (Pi) CYG in the NE, fading diffusely in the west, much more sharply bounded in the east, turning anvil-shaped back to the horizon. From 1:00, continuous observations followed again (instead of the planned meteor observation...): At 01:02, a faint ray extended nearly vertically above the dome to Beta CEP (in NNE). Shortly after, the ray ended in a red shimmering cloud. The red glow also returned in CYG. At 01:09, the phenomenon in CEP was already over, but: at 01:10, the red cloud suddenly returned bright in the NW in GEM (where TAU stood two hours earlier), became brighter, and the bright yellowish rays also returned. Then the red cloud gradually began to move eastward, at 01:14, brighter, reddish rays were also visible again in CEP (NE), bright rays extended to (Beta) UMI. At 01:19, the reddish light band extended from GEM to CYG. In the following minutes, the phenomenon reached its maximum. The yellowish-reddish rays in AUR and CAS became very bright. The highlight was the airplane that coincidentally flew "through" the very bright ray in AUR: In this ray, the contrail was visible as a thin black, distinct line! It must have been the unlit and thus dark contrail in front of the bright ray. The airplane itself was only perceivable as a point but seemed to "glow" reddish! During the maximum, a regular "curtain" of yellowish rays (rays, as always, almost vertical and slightly inclined to the top left) in a red glowing "cloud" extended from about AUR to CYG from about 10° to 50° above the northern horizon. Incredible, fantastic!!! At 01:26, the red glow reached up to the zenith, the intense cloud in the NW became weaker. The light dome, which was also visible the whole time, now rose and at 01:30 became a light arc extending from (Zeta) GEM above (Alpha) PER and CAS to (Epsilon) CYG. Now the red rays also reached up to the zenith (UMA). The phenomenon was brightest in CAS; yellowish streaks reappeared! (01:39) In the east, the bright red glowing area now moved southward to HER, later (around 02:00) even to OPH (in E). At 01:43, a bright, presumably greenish spot appeared below CYG for the first time. In the west, a faint yellow ray now rose to LEO! The yellowish rays in the north gradually drifted eastward while the red "background glow" faded. The number of yellowish rays increased, whole bundles of rays formed. They all drifted eastward. The bright ray that 01:45 moved across Alpha PER reached Alpha CAS at 01:48 and disappeared in CEP at 01:50, while a ray in CYG (ENE) became very bright. The rays now shifted to the eastern half of the sky while only a faint red glow remained from CAS (in N) to GEM (in NNW). A new ray extended over HER into BOO, which was near the zenith. After a few minutes, it transitioned into a shimmering red cloud. Occasionally, rays continued to appear in the north, quickly becoming bright and then fading just as quickly.
(02:04) Bundles of rays now converged south of the zenith at Arcturus (BOO). In the following minutes, various brighter greenish(?) spots appeared, but were always short-lived (above LYR in ENE and in CNC in WNW). At 02:08, the "front" of the aurora advanced south to the line Alpha OPH-Alpha BOO. (02:12) In CEP, the red cloud reappeared, the rays returned and became brighter (from AUR to CEP): it started again!!! Bright red cloud in AUR, red streaks in GEM-CEP, bright (greenish) band from Epsilon BOO over CRB to Delta HER... Meanwhile, the entire "palette" of phenomena had been seen several times, there was nothing "new" anymore. (02:17) converging rays again from the sector of LEO to HER (towards Eta BOO), obviously always in nearly the same place! The entire northern half of the sky was covered by the reddish "glow"! 02:30 bright rays again in N and NE (in CAS and LAC/CYG) that extended from the horizon up to the zenith region. 02:37 and in the following minutes: rays converged directly on Alpha BOO and extended to about 5° near the star. The sector from which the rays came extended over about 160° (GEM-UMA-DRA-HER). Nothing further was visible in the west now; the event now shifted clearly into the zenith region!
After a short observation break, at 02:50, only a solitary ray in CAS was visible, with almost no red glow discernible. (02:54) The light dome was visible again but shifted to NW and extended from HYA over (Alpha-Beta) GEM to (Alpha) AUR. After another break, everything seemed to be gone by 03:02. One last time, red rays appeared again in AUR, which at 03:06 combined into a weak ray "curtain" (from AUR to CAS). However, these rays were only visible for fractions of a minute. As the end of the aurora was in sight and the sky had become dark enough again, I began meteor observation. At 03:12, nothing of the aurora phenomenon was visible: light dome gone, rays gone, spots gone, red glow gone, everything gone!!! It was again the "normal" sky, appearing as usual, as if nothing had happened!!! (No further phenomena until dawn began around 05:30).