Photometry, Spectrometry, and Polarimetry of FG Sge in the Active State

摘要

Photometric, spectral, and polarimetric observations of FG Sge during the stage of increasing activity in its R Coronae Borealis type variability are presented and analyzed. a weakening of the current level of rare transient states of maximum brightness is interpreted as a consequence of increasing optical thickness of a permanent circumstellar envelope. The brightness of the He1-5 nebula in the instrumental system in the U-c and V bands is 20(m).69 +/- 0(m).13 and 23(m).01 +/- 0(m).58 from a square arc second, respectively. Luminosity was not detected in the R, B, and I-c bands.