Luminosity Class of the Symbiotic Stars 4U1954+319 and ZZ CMi
Zamanov, R.; Stoyanov, K. A.; Takey, A.; Minev, M.; Latev, G.; Marti, J.; Elhosseiny, E. G.; Christova, M. D.; Vujčić; , V.; Moyseev, M.; Marchev, V.
Bulgaria, Spain, Egypt, Serbia
Abstract
We performed optical photometry and spectral observations of the symbiotic stars 4U1954+319 and ZZ CMi. For 4U1954+319, using high-resolution spectra, we, measure the equivalent widths of diffuse interstellar bands (DIBs) and estimate the interstellar reddening E(B−V)=0.83 ± 0.09. Using the GAIA distances and our photometry, we find: (1) the absolute V-band magnitude MV=−5.23 ± 0.08 of 4U1954+319 and that the mass donor is a supergiant of luminosity class Ib, and (2) MV = −0.27 ± 0.2 for ZZ CMi and that the mass donor is a giant of luminosity class III.