The R Aquarii nebula.

Photoelectric observations were made of the emission line fluxes of the R Aqr nebula on 16 nights for the period of July 20, 1977 to November 15, 1979, with apertures between 16 arcsec and 4 arcmin. The total H-beta flux was variable and showed changes up to a factor of 2.5. The H-alpha/H-beta ratio indicates a high degree of reddening, c(H-beta) = 0.88 + or - 0.12. The mass of the central nebula was about 0.00001 solar mass, and there appears to be strong concentration toward the inner second of arc. The effective temperature of the exciting source is estimated from standard radiative considerations to be 50,000 to 60,000 K, with a luminosity ratio (L/solar L) of 5-20. A knot of gas 40 arcmin east of R Aqr exhibits a spectrum whose excitation is much lower than that of the central nebula.