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Full-Text Articles in Physics
Evidence Favoring Nonevolutionary Cepheid Masses, Norman R. Simon, Edward G. Schmidt
Evidence Favoring Nonevolutionary Cepheid Masses, Norman R. Simon, Edward G. Schmidt
Edward Schmidt Publications
It is suggested that the bumps on the velocity curves of nonlinear Cepheid models may be understood as the consequence of a resonance between the fundamental and the second overtone modes of the pulsating star. Thus the presence of bumps can be inferred from linear calculations. The region of the observational instability strip containing bumps is compared with the location of the calculated resonances. As was the case for the nonlinear calculations, we find that masses considerably less than evolutionary values are required to bring agreement between the observations and the theory.
(R - I) Colors Of Cepheids And Yellow Supergiants In Open Clusters, Edward G. Schmidt
(R - I) Colors Of Cepheids And Yellow Supergiants In Open Clusters, Edward G. Schmidt
Edward Schmidt Publications
(R - I ) and (b - y) observations of nine Cepheids which are members of open clusters, 14 field Cepheids, and 34 nonvariable yellow giants in or near open clusters are presented. Colorcolor relations for the Cepheids are found to differ significantly from star to star. Additionally, the nonvariables may differ from the Cepheid color-color relation. Pulsational masses are determined for the Cepheids using both (R - I) and (B - V) colors as temperature indicators. For some of the shorter period stars the (R - I) masses agree with evolutionary masses, which is not the …
Four-Color And Hβ Photometry Of The Galactic Cluster Ngc 6633, Edward G. Schmidt
Four-Color And Hβ Photometry Of The Galactic Cluster Ngc 6633, Edward G. Schmidt
Edward Schmidt Publications
Photometric measurements of stars in the intermediate-age galactic cluster NGC 6633 are presented. From these data the color excess is found to vary slightly across the cluster with an average of Eb – y = 0m.124. The distance modulus is found to be 7m.711 and the turnoff occurs at about (b – y)0 = 0m.l. The cluster is slightly metal poor.