Velocity Structure of Stellar Atmospheres: R Scuti
Abstract
Ten 2 micron spectra of R Scuti, the brightest RV Tauri variable, are analyzed. The period, determined from the atomic absorption lines, is 142 days, not 70 days as proposed to explain the visible spectrum. The infrared atomic absorption lines trace out a continuous, repeatable velocity curve which is interpreted as the radial pulsation of the star. The mean velocity is 37 km/s and the net displacement during a cycle is 5 x 10 to the 12th cm. The CO lines form in the cooler upper atmosphere. The dominant feature is material falling toward the star at about 20 km/s. The region is supported by a shock wave which passes through it once each pulsation; material heated by the shock is responsible for the formation of the CO emission lines. An extended envelope where the atomic emission lines form surrounds the star.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1987
- DOI:
- 10.1086/165053
- Bibcode:
- 1987ApJ...314..242M
- Keywords:
-
- Stellar Atmospheres;
- Stellar Oscillations;
- Stellar Spectra;
- Variable Stars;
- Velocity Distribution;
- Absorption Spectra;
- Carbon Monoxide;
- Emission Spectra;
- Infrared Spectra;
- Shock Waves;
- Astrophysics;
- SHOCK WAVES;
- STARS: EMISSION-LINE;
- STARS: INDIVIDUAL CONSTELLATION NAME: R SCUTI;
- STARS: PULSATION;
- STARS: RV TAURI;
- STARS: VARIABLES