The Gravitational Redshift of 40 Eridani B

Image-tube coud spectra of the DA white dwarf 40 Eri B give an independent determination of the gravitational redshift as +27 km ; prime4ocus spectra give +16 km , or a mean +23 I 5 km s-l. The agreement with the theoretical mass-radius prediction is within the experimental errors of both. No large quadratic Zeeman effect exists. Sharp cores of Ha and HP apparently arise from non-LTE effects. The maximum allowable projected rotational velocity suggests a long period. If contraction of a redgiant core leads to a white dwarf, then either the red-giant core did not rotate rapidly or it lost magnetic field and angular momentum. The coud measures now preclude a large systematic error in our primefocus redshifts of DA stars.