A stellar university experience

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This is the English version of our blog article from 30 September 2019.
Translation by Vera Oberhauser (5aR).
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At the beginning of the 2019/2020 school year, three students of the astronomy group were given the very special opportunity to undertake an internship at the university observatory in Munich. Dr. Arno Riffeser, who was born in Eppan and is a very dear friend of our astronomy group took Pauline, Dominik and Vera under his wings and granted them an insight into the world of an astrophysicist.

Vera describes this five day adventure in the following report.

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Once again, September was just around the corner which for a lot of us meant back to school season. Before we let that happen though, some students of our astronomy group went out into the field! Pauline (Matura 2019), Dominik (5dR) and Vera (5aR) set off for Munich to the observatory of the Ludwig Maximilian Universität. Dr. Arno Riffeser, who is working there, invited us to a physics practical including an overnight stay at the Wendelstein Observatory — and it’s fair to say we really didn't want to miss out on that!

Monday, September 2, 2019. Following a rather sleepy “good morning” which the three of us murmured to one another at the gates of the observatory, we suddenly found ourselves in one of the lecture halls, very focussed on Arno’s words. After a brief round of introductions, we were immediately engaged in today's topic: the Balmer series of the hydrogen atom. And that was introduced with nothing less than the Schrödinger equation — no wonder, had smoke been seen rising from our heads. Schrödinger was followed by Heisenberg and, with the use of literature value of the Rydberg constant, and of course the explanations provided by Arno, we soon were able to work out the wavelengths for the Balmer lines Hα to Hδ.

Image 1: Dominik and Pauline at work.

Wouldn’t it be much nicer though not to rely on any literature values at all and to determine this ominous Rydberg constant ourselves? Exactly; we, too, thought so! Therefore, shortly after, we could all be found gathered around the optical table, full of zest for action and ready to conduct the first measurements of the week.

The plan was as follows: The light of a hydrogen vapour lamp was to be directed via a slit and a lens, the so-called collimator, onto a grid, which would then split this light into its components. This split light was then directed through another lens, the objective, to a camera chip whose images were simultaneously processed and displayed on the computer. No sooner said than done and briefly after we were back in the lecture hall — with smoking heads (and smoking calculators)!

Image 2: Excerpt from my smoky manuscript.

Tuesday went by similarly, but this time a deuterium vapour lamp and a finer grid came to use. At some point throughout the day Arno remembered that some time ago a telescope at Wendelstein was replaced and it had been here in Munich ever since. It had neither been balanced nor aligned and was just lurking around in the garden shed which could be seen from our newly claimed working space for this week. The question whether we wanted to help set it up could be spared as we had already left everything and were heading for the door.

As it was still bright outside, we decided to first tackle the task of balancing the telescope. A masters student, who had written his dissertation on this exact telescope, kindly helped us with that. 

In order to achieve proper balance, so that the engine moving the telescope would only need very little force to do so, we had to shift the tube of the telescope up or down and add more weight to the counterweight rod. Our tools were — as one would expect from university students — only the best of the best: a ballpoint pen, which we had just found on the floor and loads of gaffa tape to attach additional weights [sic!]. In the end, it‘s not the tools, it’s how you use them, right?

Later on that day, after the sun had set, we dared to undertake the task of aligning the telescope: After quickly skimming through the resources Arno had given us on the tube on our way there — proper university students, what else can i say? — we concluded using a pointing model would be the way to go. We pointed the telescope at 11 stars, which then had to be adjusted to the center of the field of view while lying in sometimes rather uncomfortable positions on the cold concrete. Afterwards it was finally time to start observing and, despite the heavy light pollution in Munich and some tall treetops blocking our view, we got to see several planetary nebulae, globular star clusters and our next-door neighbour, the Andromeda galaxy.

Image 3: Our workhorse! Who's heart does not beat faster at this view.

Wednesday was finally the day we have all been waiting for: Arno had promised us to go to Wendelstein. With a fully packed backpack and a sleeping bag under our arms we got into the car and, after a short break, into the cable car, which took us to the 1800 meter high summit. Once we reached the top, we went straight to the Cloudé telescope from the 60s and carried out a sun observation. We also tried photographing some solar prominences (emphasis on the word “tried”), but unfortunately, we were left with blurry pictures. 

Since we had already been working with grids in the previous days, it was no surprise that we soon started to take spectra after concluding our solar observation. Besides the already pre-selected vapour lamps and the star Vega we also aimed at 61 Cygni A and B, old acquaintances of our astronomy group. After we had gathered all of the data needed for our analysis, it was time to go off the rails! We took pictures of all sorts of objects through different filters, which we then superimposed on each other to obtain so-called "pretty pictures". A missing blue filter rendered the whole thing a little more challenging, but some of the pictures still turned out quite well! 

Our observation night at Wendelstein came to an end, when clouds came up at 5 AM and even the last of us crept downstairs to the sleeping quarters. One could say we might have gone a bit overboard there, but in all honesty, what else did you expect when three eighteen-year olds got left in full charge of a 43 cm telescope?

Image 4: The three trainees in front of the 2-m-telescope.
From left to right: Vera, Dominik and Pauline.

Image 5: The Dumbell nebula in the constellation Vulpecula.
The result is slightly yellowish due to the lacking blue filter.

Back in Munich we analysed the collected data and were allowed to accompany Arno to two experimental setups, which the physics students of the university would presumably soon have to face. On Friday we continued the analysis and processing of the images until our internship at the Ludwig Maximilian Universität came to an end.

With a heavy heart we said our farewells after this far too short week and sadly got on the coach, which took us home and thus also back to the benches of the Cusanusgymnasium Bruneck. Only Pauline is lucky enough to be sitting in the lecture halls of the LMU in just a few weeks.

All of us would like to thank Arno Riffeser once again, who has made this internship possible in the first place and who turned this week into a memorable experience that we will not forget anytime soon! Thank you!!

Vera Oberhauser (5aR)