Symbiotic Stars

A symbiotic star is a type of binary star system that consists of a white dwarf and a red giant. The cooler red giant loses material which flows onto the hotter compact dwarf star. Symbiotic stars are of interest to astronomers because of specific astrophysical processes that can be studied during their evolution such as stellar winds, accretion, and the ionization of surrounding dust and gas. During their evolution, symbiotic stars show large, irregular fluctuations in brightness.

PU Vul

Shown below is a sonified video showing the light curve of a symbiotic star called PU Vul. There are 184 observations taken over almost 4 years. The irregular fluctuations in brightness can be heard clearly, along with the trend that the star declines slightly in brightness. The video scans over time (x-axis) and modulates pitch based on magnitude (y-axis). Lower pitch represents dimmer magnitudes.

Next, below is a sonified video of the optical spectrum for PU Vul. This video scans across a plot of brightness measured in flux or intensity of light (y axis) versus wavelength (x axis), moving from blue to red wavelengths from 3800 to 7200 angstroms. Lower pitch represents weaker flux. As wavelength increases, the spectrum stays at a near constant baseline flux that is broken by frequent sharp emission lines. The strongest emission line, H-alpha, is toward the red end of the spectrum.

Thanks to Dr. Scott Kenyon for providing the light curve and spectral data for PU Vulpeculae.