Bibcode
Aznar Cuadrado, R.; Montañés Rodríguez, P.; Jeffery, C. S.; Pollacco, D.
Referencia bibliográfica
The Impact of Large-Scale Surveys on Pulsating Star Research, ASP Conference Series, Vol. 203; also IAU Colloquium #176. Edited by L. Szabados and D. Kurtz. ISBN: 1-58381-030-7 (2000), p.438-439
Advertised on:
0
2000
Número de citas
1
Número de citas referidas
1
Descripción
Z-bump opacities are known to excite radial pulsations in helium stars
with 102~<= L/M~<=104 and Teff ~
25 000 K. Well-studied cases are V652 Her and BX Cir. The absence of
variations in the metal-poor star HD 144941 demonstrates the importance
of Z-bump opacitiesto drive these pulsations. Several other helium-rich
stars lie close to the theoretical blue-edge of the Z-bump instability
strip. One of these, LS IV+6o2, is a known radial velocity
variable. We report on recent (1999 June) observations of two helium
stars close to the Z-bump instability boundary. Both appear to be
variable.