PHAS3332 (Practical Astronomy 3: Field Trip) 2008

IMAGING PHOTOMETRY OF PULSATING VARIABLE STARS

The report on "Imaging Photometry of a Pulsating Variable" is the second of three reports which all students taking part in the Field Trip should submit. This report should be submitted by the end of the first week of the Third Term. It is worth up to 250 marks.

The photometry report must be submitted separately from the report on spectroscopy. You will lose marks if the two reports are bound together.

The report must include the following items:

1. A title page, which must display your name, the course description (PHAS3332 Third Year Observational Astronomy 3: Field Trip), the title of the project, and the date of submission of the report.

2. An abstract: a statement which summarises the major achievement(s) of your project. Include your most important numerical results, the uncertainties on these, and whether they agree (to within the uncertainties) with any relevant values found in the literature.

3. An introduction. This should set your work in context and include a discussion of some recent literature on RR Lyrae stars as a class of objects, and RR Gem and/or XY CVn in particular.

4. A section on data acquisition, which is a detailed description of your observing sessions on the 1.20-m telescope. What problems did you encounter, and how did you overcome them?

5. A data reduction section. Describe how you used Figaro and Gaia to calibrate and measure your CCD images. Discuss any problems encountered, and evaluate the quality of your magnitude estimates.

6. A section on data analysis. Plot light curves (magnitude as a function of Julian day) for both the B- and V-band data. Estimate the period and amplitude of variation in each curve. Subtract the V-band from the B-band light curve, and investigate how the (B-V) colour of the system varies with time.

7. A clear and concise statement of your results: the periods and amplitudes of the light curves.

8. A conclusion, discuss the results you presented in the previous section. How reliable are your results? How do they compare with any values in the literature? What are the implications of your results? Discuss whether the project was an overall success, and how you might do things differently if you embarked upon a similar project in the future.

Aim to cover all of the above points in a report of approximately 3000 words. If you follow the guidelines given above, you should be able to include everything that the markers of your report will expect to read, without writing an excessively long report.


Click the following link for hints on photometric data reduction.

Log of the observations made with the 1.20-m telescope during the 2008 Field Trip (pdf; size is about 40 Megabytes). Because of cloud and rain, no observations were made on the night of January 29.


Stephen Boyle
Last updated: 2008 February 6