Seminar: Distance Indicators


The goal of this exercise is to investigate the methodology and reliability of the distance indicators used to measure distances in the universe. The results of your investigation will be summarized in a report and presented in an oral contribution in front of your peers. In the process you will gain: (i) an understanding of the basic methodology to measure distances using empirical relations between various stellar and galactic parameters, (ii) a critical look at the various sources of uncertainty associated to these measurements and their effects on the cosmological parameters and the distribution of matter in the universe, and (iii) experience to present your ideas in a logical, well-organized manner in front of a audience with mixed scientific backgrounds. Guidelines for preparing the talk and the report are given below. Useful reference texts and review articles are: "The Extragalactic Distance Scale", eds. M Livio, M. Donahue and N. Panagia, Cambridge University Press 1997, and "A critical review of selected techniques for measuring extragalactic distances" Jacoby et al. (1992, PASP, 104, 599). You are encouraged to search the literature for updated review papers on the subject.

Students will work in groups (2 students). Each group will choose a distance indicator from the following list:


The talk will consist of a 12 minute oral presentation plus 3 minutes for questions. No overtime will be allowed. Note that this is a short presentation. You should aim to ensure every person in the audience will achieve a basic understanding of the pros and cons associated to the use of a particular distance indicator, avoiding getting bogged down in details that can be addressed during the question time, or in the written report. You will be required to address the following four items in your talk:


The report will consist of a 10 pages essay offering an in-depth, detailed description of the same four items mentioned above. Any use of previously published text should be appropiately identified in quotation marks and the reference should be given. I strongly discourage you to simply copy the text from the literature unless you are subsequently discussing such text in detail.

The layout of the report is as follows (no information beyond the page limits for each section will be considered):