Placement of Bright S88B Objects on a Hertzprung-Russell Diagram Using Visible Light Measurements

Geoffrey A. Bonvallet

In this experiment we attempted to determine the placement of S88B stellar objects in a Hertzprung-Russell diagram. A charged-coupled device (CCD) camera was used to observe the HII region S88B at visible wavelengths through B, V, R, and I Johnson filters. Four major stars were observed and their flux densities were digitally measured and compared with those of standard photometric stars. The magnitudes of the S88B objects at each filter wavelength were calculated, and color-color and magnitude-color plots were made from the data. The data suggest that extinction significantly affected the measurements, but was not quantified. Similarly, infrared excess was apparent and reflective augmentation of lower wavelengths may also be present. Overall, the experiment demonstrated an ability to take photometric measurements of stars using the equipment available at The College of Wooster, but more data from standard stars should have been taken to improve the quality of the work.


S88B images taken with different filters. The shorter-wavelength images are dimmer.