Confirmation of the decreased pulsational amplitude of Polaris
Abstract
Data from radial-velocity observations of Polaris, obtained at dispersion 8 A/mm on 34 plates using the blue image slicer and Cassegrain spectrograph on the 1.9-m telescope at David Dunlap Observatory during March-September 1983, are presented in tables and graphs and characterized. The best fit to the data is obtained using a sine curve with amplitude 1.4 + or - 0.3 km/sec, in agreement with the findings of Arellano Ferro (1983) and showing a marked decrease from the 2.8 km/sec amplitude found in the averaged Lick Observatory data for 1896-1958 by Roemer (1965). The difficulties encountered in an attempt to fit the Lick data with a sine function having a secularly varying period with higher-order phase-drift terms are discussed.
- Publication:
-
Journal of the Royal Astronomical Society of Canada
- Pub Date:
- October 1984
- Bibcode:
- 1984JRASC..78..173K
- Keywords:
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- Binary Stars;
- Cepheid Variables;
- Stellar Oscillations;
- Supergiant Stars;
- Orbital Elements;
- Radial Velocity;
- Astronomy