SIMBAD references

Hα spectroscopic observations have been made by using a high-dispersion and high-resolution thick CCD system, when the orbital phase of ε Aur was near 0.3. During two years of out-of-eclipse observations, the Hα profile varied significantly. The circumstellar gas circling the F0 supergiant is possibly a ring-like H II structure, which consists of moving gaseous clouds. Hα profile variation outside eclipse may be due to the apparent motion of gaseous clouds within the ring following the rotation of the primary, and to its intrinsic physical changes.