Preliminary results of the study of beta -Lyrae during the international campaign of July - August 1971.
Summary. From a study of spectrograms of p Lyrae in the spectral range taken during the period July 18-August 1, 1971 it appears that the radial velocities given by the absorption cores of Hoc, HP and of the non-metastable lines of He i, 6678 and 5875 vary out of phase with the orbital velocity curve showing a minimum of about -120 km s- at phase 0d and a broad maximum of about -50 km s ' at phases included between 5d and 10d The metastable line of He i 5015 and the two shell components of the Na i D lines have an almost constant velocity of -120 km s ` The radial velocity of the center of the emission lines Hoc, 6678 and 5875 is roughly constant and equal to the velocity of the center of mass of the system. The epochs of the appearance of the red and violet satellite lines of Si H confirm the photoelectric data for the epoch of the minimum which occurs about 0d13 before the predicted epoch. The absorption line intensity is minimum and the emission intensity is maximum at light minima. Key words: P Lyrae red spectrum - radial velocity - line intensity
Astronomy and Astrophysics
- Pub Date:
- April 1973