EG Andromedae: A New Orbit and Additional Evidence for a Photoionized Wind
Abstract
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 orbital period P = 483.3 +- 1.6 days and semi-amplitude K = 7.34 +- 0.07 km/sec. Combined with previous data, these observations rule out an elliptical orbit at the 10-sigma 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 of roughly 75,000 K ionizes the wind from the red giant.
Keywords
Cite
@article{arxiv.1604.04635,
title = {EG Andromedae: A New Orbit and Additional Evidence for a Photoionized Wind},
author = {Scott J. Kenyon and Michael R. Garcia},
journal= {arXiv preprint arXiv:1604.04635},
year = {2016}
}
Comments
16 pages of text, 2 tables. 6 figure, Astronomical Journal, accepted