Infrared light curves for V1057 Cygni (1971--74

Broadband infrared photometry at 5μ, 10μ, and 20μ is presented for V1057 Cyg (= LkH PHA 190 The observations extend from 1971 July through 1974 July, during which time the 5μ brightness has remained essentially constant and the long-wavelength fluxes have decreased by approximately 0m8. The origin of the flux excess observed at wavelengths between 1μ and 5μ is uncertain; remnant circumstellar dust, which is radiatively heated by a central point source of declining luminosity, provides a satisfactory explanation of the 10μ and 20μ light curves. (U.S.)