SIMBAD references

We analyze a roughly 20 yr set of spectroscopic observations for the symbiotic binary EG And. Radial velocities derived from echelle spectra are best fit with a circular orbit having an orbital period of P=483.3±1.6 days and semi-amplitude K=7.34±0.07 km/s. Combined with previous data, these observations rule out an elliptical orbit at the 10σ level. Equivalent widths of H i Balmer emission lines and various absorption features vary in phase with the orbital period. Relative to the radius of the red giant primary, the apparent size of the H ii region is consistent with a model where a hot secondary star with effective temperature T_ h_ ≃ 75,000 K ionizes the wind from the red giant.