Abstract
HD 211853 is a known spectroscopic and eclipsing binary, consisting of a WN6 star and a companion which has been classified by Morgan, Code and Whitford (1955) as BO: I. A spectrographic orbit was published by Hiltner (1945); a light curve was published in 1963 (Hjellming and Hiltner 1963), together with a revision in the period. The present paper is based on low-dispersion (128 Â/mm) spectrograms obtained in 1964 and 1966 at the Kitt Peak National Observatory, and measured on a Grant comparator. A further slight change in the period was found necessary to bring the present observations into phase with those of 1944: the revised period is 6.6881 days. Hiltner's circular orbit is confirmed; however, the orbital analysis of the present observations gives a somewhat larger semiamplitude for the emission. The present work gives a value of K of 285 km/sec ( see Figure 1 ) , compared to 245 km/sec published earlier. The differences may be due to the fact that the present work uses only the He n A 4686 line, rather than averaging several emission lines of He n, N v, and N iv. The value of y from A 4686 is 75 km/sec. Hiltner's absorption-line velocity curve did not seem to follow a sine curve; in the present work it is possible to fit a sine curve with a semi-amplitude of about 100 km/sec and y of 95 km/sec (see Figure 2), except for discordant observations on September 8, 1966 (phase 0^15).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Publications of the Astronomical Society of the Pacific
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.