Darmstadt - Hans-Günter Diederich

Now that I am looking north again, away from the southern sky where TW_Vir is, I notice something strange: To the north "suddenly" (previously unseen) very strong light pollution, as if Frankfurt had been replaced by the floodlights of LA. Above it a broad diffuse red arc, as if the entire Rhine-Main region were on fire. This was the first moment I thought of an aurora (northern lights, Aurora Borealis). And I had just seen the large spots on the sun. Here are initially quotes and other things, including my attempt at classifying the structural elements seen in the aurora. The diary continues below ... when writing: However, I did not know about the alerts yet, I read them first the next morning). Structural elements of the aurora phenomenon (written down from memory the following day) Element 1:

a roughly 5-degree wide white slightly greenish band flat over the horizon from NW over N to NE on a circular arc. Below it was dark up to the light haze on the horizon. So it couldn't be man-made light pollution. Always present from 23:30, initially quite sharply defined, later diffuse and broader.

Element 2: Above E1 another roughly 5 to 8-degree wide white slightly greenish band also on a flat circular arc. From about 1:30. Separated from E1 by a dark area. At the lower edge, linear parallel structures formed pointing upwards away from the horizon. Shortly afterwards it then went round. 

Element 2a: From the uniformly bright band in azimuth, brighter oval areas emerged in the NE and NW against 1:20. Element 3: Red clouds, diffuse, arranged on a circular arc with a smaller radius above Element 1 (E2 not visible yet). Around 23:30. Then in or better in front of Per and Aur a feathering, streaked, diagonally upwards oriented towards S. Element 4: From 1:30 extremely long streaky structures from the horizon upwards beyond the zenith to S. Almost razor-sharp and drawn as if by a ruler. As if produced by giant laser disco beams, intersecting behind the zenith in S. Predominantly red, but with yellowish rays in between. Then again becoming diffusely blurred. For all elements the following applies: No movement of the structures in position, only slow changes in the *sharpness* (diffuse - streaked - diffuse again). Exception at 23:24. ... I see radial streaking from the N-horizon upwards. Below is the light haze, white, wide but unnaturally high (15° elevation).

Four diffusely wide reddish strips, directed upwards away from the horizon, are arranged on a circular arc, which is 45° high in the N and descends to the horizon in the NW and NE. The diffuse-wide reddish strips or oval areas are located on this arc in NW, in N (2 pieces next to each other), and in NE. The arc starts from Per, passes N by Cas, through Cep. 

In the two northern diffuse-wide strips, I now see two narrow, long, white stripes reaching up to the zenith. Apart from the appearance (sharpening, then blurring again), there is no rapid change, thus no rapid change in position.

A narrow white band rises in the NW near the horizon and culminates in the N. I run through all the "man-made" possibilities for this phenomenon (fireworks, disco beamers, Main-in-Flames, large fire, ...), but it can't be any of those. I'm still not completely convinced by the "northern lights" explanation. 

The red areas on the arch are now weaker, now a narrow white strip going up from the NW. It is quite bright in the N (white) and getting even brighter. The red arc has disappeared, the initially narrow strip in the NW has widened, become weaker, and changed its color from red to white, now looking like a large oval 15° from the horizon towards the zenith, a diffuse 5° wide red mist. Now it is becoming round.

And now a medium-speed meteor flies right through this red cloud coming from the direction of the zenith, fading away in a 15° long white trail in Per. The backward extension points to Vir from the starry sky: Virginids, flat maximum around April 3, until the end of May, average speed 30 km/s (slow), low frequency. The red cloud in Per intensifies, becomes palm-sized. On its left side (NW) a white stripe-shaped structure, extending to the top left with a sharp boundary on the left side. Becomes weaker. The red area slowly moves to the left and now reaches up to Capella. The bright light haze is clearly visible again: it is a flat arc, 10° above the N-horizon, NW to NE, its magnitude less than 5°, does it have something to do with the northern lights? It had indeed disappeared for some time and is now getting stronger again. 

The red round nebula between Per and Aur is still present and is noticeably on a segment of a circular arc. The bright white light in the N (previously called "light haze") must be related to it, as it shows a trace of green. Additionally, stars are visible through it, which I cannot imagine with a real haze at this intensity of light. And it is extremely bright.

Below it, there is a narrow dark zone parallel (or better, concentric), which really borders the usual low zone of truly "man-made" light haze. With this, I can also identify the white arc as part of the northern light phenomenon. Very narrow white stripe, better beam, from the NW horizon slanting high into Aur into the red nebula area there. Aur to the NWN horizon weakly reddish.

Reddish double beam rising from Per to Aur. The reddish fog there is now dissolving into several parallel red stripes. Meteor from Aur towards Tau, probably also a Virginide. 

Amazing! Very bright, red with a color change to white in Aur, lots of parallel stripes going up at a 45° angle from NW to Aur, forming a whole slanted 10° wide red arc section. I notice that I am no longer observing with my telescope, which stands unnoticed behind me looking into the S.

I feel the moment has come to call the on-duty editor at the Darmstäder Echo. The mobile phone is unpacked, logged in, the connection service called (surely very expensive). I end up with the porter, who informs me that besides in the rotation, where the newspaper is already being printed, no one is there. When I ask how important messages are received at night, I hear "by teleprinter." My communication technology is not yet developed to that point outdoors at night... The red formation in the NW has shifted and rises as a broad red band of constant width of 8° from WNW up to Tau. In it, I believe I can also see rapid movements, for the first time this night. 

The flat narrow greenish-white band in the N is still present.

The center of the red areas has shifted from N to W by almost 90° within half an hour (depending on how you define the initial center) to W. The red mist areas disappear, the flat narrow greenish-white band is now very bright, especially in the NE, and much wider than in other places. Another brightness maximum is now in the NW, not where this arc culminates.

The red has now disappeared, the flat white ring has become even brighter with a maximum in the NW.

The flat white band has increased in width, it is no longer as distinct as before but appears much more diffuse and extended in its magnitude (vertical extent). Outside of the ring, it has also become brighter. The flat white band is now so bright that I almost feel dazzled when I look directly at it. The red area in the NW in Tau becomes visible again.

In the NE outside of the flat white band, a faint reddish glow now appears as the eastern approach of a not fully visible red circle band that ends on the left in Tau.

Above the flat white band (in the N), the entire sky up to a height of 45° has become brightly white. Above this brightness, a reddish shimmer appears in the NE. The dark narrow area between the horizon light haze and the flat white now diffuse band is still visible and unchanged.

Weakly reddish in dew, outshone by the very bright white band. The sky in the south also looks somewhat bright: is that glare or does a part of the northern lights also appear here, albeit weakly?

Conditions: 2.5°C And once again I look at the now broader diffuse bright white band: in the NW I now believe I can see a faint radial-streaky white structure in this band. Then a weak narrow stripe goes briefly all the way up to the zenith. The radial-streaky white structure becomes clearer, briefly again a narrow stripe from or into it up to 45° high to the right past Capella. 

The bright diffuse white band now shows this kind of streaky structure in the north as well, it changes before my eyes, at its lower edge these structures even reach slightly into the previously mentioned dark area from above. The extension towards the horizon-zenith of these structures reaches 20° and sometimes slightly more, standing vertically in the N. With a bit of imagination, I picture these as the "curtains" I have seen in aurora photos.

I'm utterly speechless: I have to interrupt the dismantling of the telescope and my equipment because the entire sky from NE over N to W is crossed by fine elongated streaks, whitish at the bottom and reddish at the top, reaching beyond the zenith! Incredible!!! Like oversized searchlights, no disco beam can compare! They constantly change, the delicate fine structure gives way to a diffuse appearance within fractions of a minute. Yellowish-white, others red, all extending in the same direction towards the zenith. 

The impression around 23:30 is now exceeded tenfold.

The diffuse streaks fade, lastly in N, giving way to a diffuse red light covering the entire northern sky. Only the streaky structure in E (almost a "wall") remains until the end, but now finally loses its fine structure.

Cloud-like red areas in W are weakening, most visible now in E. 

Above the diffuse bright white band in N, a second dark parallel zone has formed. So another bright zone must have formed above it. And I marvel at how quickly these delicate structures blur. when writing: 

Could it be that the delicate structures are created by short-lived particle streams and immediately stretched apart by fast winds of the high atmosphere after their formation? 

The streakiness increases again. The second higher brightness band shows two maxima, in WNW and in E. 

In the NE outer region, another diffuse red area forms. Four such areas are now visible: in WNW, N, NEN, NE. They now reach up to 60° elevation. A weak structure extends to the zenith. The entire north sector is bright, red or white.