![]() ![]() ![]() Renzini (Kluwer Academic, Dordrecht, 1992), p. Kurucz, Proceedings of the 149th IAU Symposium on Stellar Populations of Galaxies, Ed. The star ϵ Leo should be assigned to bright supergiants, while HD 187299 and HD 190113 may have already passed the second dredge-up and move to the asymptotic branch.Ī. Judging by the abundances of the key elements and its position on the T eff−log( L/ L ⊙) diagram, the lithium-rich supergiant HD 172365 is at the post-main-sequence evolutionary stage of gravitational helium core contraction and moves toward the first crossing of the Cepheid instability strip. The СNO, Na, Mg, and Al abundance estimates have shown that eight of the nine NVSs from the list have already passed the first dredge-up. The abundances of α-elements, r- and s-process elements for all program objects have turned out to be nearly solar. The evolutionary masses of the objects have been estimated. (2000) are used, out of the NVSs from the list on the diagram one is within the Cepheid instability strip but closer to the red edge, two are at the red edge, three are beyond the red edge, two are at the blue edge, and one is beyond the blue edge. When the edges of the Cepheid instability strip from Bono et al. The spectroscopic estimates of T eff and the luminosities determined from the Hipparcos parallaxes have shown eight of the nine program NVSs on the T eff−log( L/ L ⊙) diagram to be outside the canonical Cepheid instability strip. These have been used to determine the atmospheric parameters, chemical composition, radial velocities, reddenings, luminosities, distances, and radii. High-resolution spectra of nine yellow nonvariable supergiants (NVSs) located within the canonical Cepheid instability strip from Sandage and Tammann (1969) ( α Aqr, ϵ Leo, μ Per, ω Gem, BD+60 2532, HD 172365, HD 187299, HD 190113, and HD 200102) were taken with the 1-m Zeiss and 6-m BTA telescopes at the Special Astrophysical Observatory of the Russian Academy of Sciences in the 1990s. ![]()
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