Telescopes and lab courses
The Argelander Insitute for Astronomy (AIfA) operates two telescopes on its roof: a 35-cm optical telescope and a 3.2-m radio telescope. These are designed as educational facilities, and are primarily used by students in the scope of lab courses. In addition, one lab course makes use of the 25-m radio telescope Astropeiler Stockert, located near Bad Münstereifel, about 35 km southwest of the AIfA.
Lab courses
Astrophysics lab courses making use of our telescopes are offered both at the bachelor and master level. The labs take place each semester.
The general structure of the courses is common to all experiments: for each group of students, they start with an oral qualifying examination (called Antestat in German) about the scientific and technical background of the experiment, followed by the actual observation, a data reduction session, and the writing of a report.
B.Sc. in Physics Lab courses (Praktikum 4, in German)
In diesem Versuch nutzen Studierende den DADOS-Spektrograph am optischen Teleskop, und beobachten Spektroskopische Doppelsterne, Wolf-Rayet-Sterne, Sternwinde, und die Abhängigkeit der Hα-Linie von der Spektralklasse.
Die Antestate finden jeweils zu Beginn der Vorlesungszeit im April (Sommersemester) bzw Oktober (Wintersemester) statt, der Zeitraum der Beobachtungen liegt dann in der jeweiligen Vorlesungszeit.
Studierende beobachten mit dem Radioteleskop die Rotationskurve und Spiralstruktur der Milchstraße anhand der 21-cm Linie des neutralen Wasserstoffs.
Der Zeitraum der Beobachtungen ist Anfang Juni (für das Sommersemester) und Anfang Dezember (für das Wintersemester).
For further information and registration, see the website of the Praktikum 4.
M.Sc. in Physics or Astronomy (Advanced Laboratory Course, in English)
Students use the optical telescope to observe an exoplanet transit, reduce their data in Python (using state-of-the-art software libraries), and infer the relative size of an exoplanet compared to its host star. While the telescope is of modest size, the whole data acquisition and analysis chain is consistent with the processing of data from professional optical observatories.
For the summer semester, the qualifying exams take place in February, followed by the observations until April. For the winter semester, the exams are in August, with observations from August to October.
The first part of this experiment provides insights into the tuning and operation of a superheterodyne receiver. In the second part students observe the radio emission of the Sun and set up a radio interferometer to determine the interference pattern.
Exams and observations take place from February to April (summer semester) and August to October (winter semester).
In this lab students acquire imaging data from star clusters, and use their data to constrain age, distance, and metallicity via the color-magnitude diagram. As for the lab "Optical Astronomy", the whole experiment is consistent with what would be done at a professional optical observatory. Many steps of the data analysis are common between these two master-level labs.
The schedule is the same as for "Optical Astronomy", as the observations are done concurrently for these two labs.
This course is offered at the 25-m radio telescope Astropeiler Stockert. The HI 21-cm line emission of the Milky Way galaxy is observed with the 25-m dish for calibration purposes. Afterwards, a HI 21-cm line measurement of an external galaxy is performed. The aim is to determine both the HI and the total mass. Finally, the distance to a pulsar is determined by examining the dispersion of the radio wave spectrum.
The observations take place mid-March and mid-September.
For further information and registration, see the website of the Advanced Laboratory Course.
Illustrative results
Transit of the exoplanet HAT-P-23 b, observed by the S261 lab. The dark data points show the light curve of the host star, in bins of 5 individual exposures of 40 s each. Error bars depict the estimated 1σ uncertainty of the shot noise of the host star alone. The solid gray light curves show reference stars, with the same calibration as for the transit host star, and with arbitrary magnitude shifts. Vertical solid lines show expected ingress and egress times.
More results to be added here soon...
Tutoring the lab courses
The astrophysics laboratory courses rely on tutoring support by experienced students and doctoral candidates. The tutors have several tasks. First, they conduct the qualifying oral examinations ("Antestate") focusing on details of each lab course, which also contribute to the final grade of each group. Then, the tutors organise and support the student groups with the observations. They also help with any questions related to the data reduction, and finally they grade the reports and give feedback to the students. The lab courses at AIfA require the supervision of up to ten groups of two students.
Tutors of a lab course will become familiar with the operation of the involved telescope at the AIfA. Extensive training and supervision is guaranteed in every case. Thanks to the excellent technical equipment of our new facilities on the roof of the AIfA, only the weather can throw a spanner in the works. For the experiment offered at the Astropeiler Stockert, an operator controls the telescope during the lab course.
It is highly appreciated if doctoral candidates tutor one same lab for up to three to four semesters. This is advantageous for the tutors as they gain strong expertise with the instrument and obtain significant experience in teaching at university level. It also ensures continuity, and is beneficial for the quality of the education of our students.
Optical telescope
The current optical telescope got installed in the wooden dome on the roof top of the Argelander-Institut für Astronomie in October 2023. It is used for all optical astronomy labs, and replaces the previous Cassgrain telescope.
- Optical tube: Planewave CDK-14
- Type: corrected Dall-Kirkham, variation of a Cassegrain
- Aperture: 356 mm (14 inch)
- Focal length: 2563 mm
- Focal length ratio : f/7.2
- Mount: 10Micron GM2000 HPS II
- Type: german equatorial, with absolute encoders
- Typical tracking error: 0.7" RMS over 15 minutes
- Imaging Camera: QHYCCD 600M PH
- Type: back-illuminated full-frame CMOS
- Size: 9576 x 6388 native pixels of 3.76 µm
- Field of view: 48' x 32' (0.6" per pixel at 2x2 binning)
- 7-position filter wheel, with:
- Photometric SDSS bands
- Narrowband (6.5 nm) Hα, OIII, SII
- Spectrograph: DADOS
- Gratings: 200 l/mm, 900 l/mm
- Camera: TBD
Radio telescope
In May 2023 a small radio telescope became available at the roof top of the Argelander-Institut für Astronomie. Its purpose is the exploration of the HI 21-cm line emission of neutral atomic hydrogen of the Milky Way galaxy. Students of the Bachelor of science in Physik use this telescope during a lab course.
- Type: parabolic dish with prime focus receiver
- Mount: altazimuth mount
- Primary mirror diameter: 320 cm
- Focal length ratio primary focus: f/0.4
- Spectrometer: ADALM-PLUTO
- Number of spectral channels: 4096
- Frequency (velocity) resolution: 1465 kHz (0.31 km/s)
