A New Velocity Curve of the RR Lyrae Star TU Ursae Majoris: Evidence for Duplicity
Abstract
Spectra taken at the coude focus of the 5-m Hale telescope were reduced to obtain a velocity curve for the field RR Lyr star TU UMa. The observations were aimed at detecting differences (if any) in the velocity curves obtained from weak metal lines shortward of the Balmer jump, as opposed to those from similar lines longward of the Balmer jump, so that velocity gradients deep in the atmosphere could be studied. The mean velocity from this velocity curve is different from those measured at earlier epochs. This suggests that TU UMa is a binary system in which the visible component is the RR Lyr star. Fluctuations in times of light maxima are interpreted here as time delays due to light travel time as the RR Lyr component moves in its orbit.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- February 1990
- DOI:
- 10.1086/132621
- Bibcode:
- 1990PASP..102..148S
- Keywords:
-
- Binary Stars;
- Blue Stars;
- Giant Stars;
- Stellar Oscillations;
- Variable Stars;
- Balmer Series;
- Charge Coupled Devices;
- Dwarf Stars;
- Main Sequence Stars;
- Stellar Spectra;
- Stellar Spectrophotometry;
- Astrophysics;
- STARS: INDIVIDUAL;
- STARS: RR LYRAE