Infrared Spectroscopy of Symbiotic Stars. X. Orbits for Three S-Type Systems: V1044 Centauri, Hen 3-1213, and Ss 73-96

Abstract

Employing new infrared radial velocities, we have computed orbits of the cool giants in three southern S-type symbiotic systems. The orbit for V1044 Cen, an M5.5 giant, has a period of 985 days and a modest eccentricity of 0.16. Hen 3-1213 is a K4 giant, yellow symbiotic with an orbital period of 533 days and a similar eccentricity of 0.18. For the M2 giant SS 73-96 the orbital period is 828 days, and this system has a somewhat larger eccentricity of 0.26. Measurement of the H I Paschen δ emission lines, which may at least partially reflect the motion of the secondary in SS 73-96, results in a mass ratio of 2.4 for the M giant relative to the presumed white dwarf. The estimated orbital inclinations of V1044 Cen and Hen 3-1213 are low, about 40°. However, for SS 73-96 the predicted inclination is 90°, and so an ephemeris for eclipses of the secondary or the hot nebula surrounding it is provided. A search of the orbital velocity residuals of V1044 Cen and SS 73-96 for pulsation periods produced no realistic or convincing period for either star.

The 2016 outburst of the unique symbiotic star MWC 560 (= V694 Mon), its long-term BVRI evolution and a marked 331 days periodicity

“…Fekel et al 2000aFekel et al ,b, 2001, and for only a small fraction of them the eccentricity is significant (eg. Fekel et al 2015). Going into details, Tomov et al (1992) and Frckowiak, Mikołajewski, & Tomov (2003) reported for MWC 560 a period of ∼2000 days, Doroshenko et al (1993) found 1930 days, while Leibowitz & Formiggini (2015) preferred 1943 days.…”

Masses of white dwarfs in symbiotic binaries

“…In a series of eight papers (Fekel et al 2017(Fekel et al , 2015(Fekel et al , 2010(Fekel et al , 2008(Fekel et al , 2007(Fekel et al , 2001(Fekel et al , 2000a we measured the single-lined spectroscopic orbit of the late-type star in 30 symbiotic binary systems. Two parameters from the orbital solution, eccentricity and mass function, can be used to evaluate the group statistically.…”