Larger project practicals (duration 2 weeks full-time)

taught at the Institute for Astrophysics, University Göttingen

The idea behin these projects is for a small group of students (3-5) to gain first research experience. The group first decides on a general topic and then picks a tutor from the respective department. Together they then elaborate the details, formulate the science goal and come up with the methods and techniques that are best suited to pursue their goal. I was mentoring two groups that both used the institute’s telescope to gather astronomical observations of stars and galaxies, respectively, to investigate the following topics:

Determination of the speed of light using the variable star VZ Cnc

Although the basic idea behind this experiment sounds simple it requires careful working to gain a reasonably acurate answer: We observe a variable star that we use as accurate metronome at different positions on earths orbit around the sun. From the different path lenghts to the star and the observed shift in the stars light-curve we can then derive the speed of light.

Spectroscopy of Active Galactic Nuclei

This experiment is in its nature an extension of the beginners lab experiment on the classification of Active Galactic Nuclei. The students used the then newly commissioned spectrograph mounted on the institutes telescope to obtain long-slit spectra of several bright nearby AGNs. Wavelength calibration was achieved via obsverations of spectral lamps with a known spectra. After data reduction and wavelength calibration the students can then derive a distance towards the galaxies via their redshifts. The shape of their emission lines furthermore allows to classify the type of the AGN into Seyfert 1s and Seyfert 2s.

Since many of the spectra were rather noisy, we decided to also obtain spectra of several bright stars to classify their spectral type by studying their effective temperature as well as the strength of several strong absorption lines.