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Full-Text Articles in Physical Sciences and Mathematics
The Spectra Of Type Ii Cepheids. Ii. The Hα Line In Intermediate-Period Stars, Edward G. Schmidt, Shawn Langan, Kevin M. Lee, Dale Johnston, Peter R. Newman, Stephanie A. Snedden
The Spectra Of Type Ii Cepheids. Ii. The Hα Line In Intermediate-Period Stars, Edward G. Schmidt, Shawn Langan, Kevin M. Lee, Dale Johnston, Peter R. Newman, Stephanie A. Snedden
Edward Schmidt Publications
We present 98 Hα profiles for 21 pulsating variable stars with periods from 3 to 8 days. The strength, depth, and shape of Hα vary throughout the cycles of the stars in a way consistent with the temperature changes. Otherwise, they are quite uniform among all the stars, with a single exception. In FM Del, Hα is weaker and has a smaller central depth than in the other stars. This and the wavelength shifts of the core are attributed to incipient emission. The differential velocity of Hα relative to the metal lines is less than 25 km s-1 for …
The Spectra Of Type Ii Cepheids. I. The Hα Line In Short-Period Stars, Edward G. Schmidt, Kevin M. Lee, Dale Johnston, Peter R. Newman, Stephanie A. Snedden
The Spectra Of Type Ii Cepheids. I. The Hα Line In Short-Period Stars, Edward G. Schmidt, Kevin M. Lee, Dale Johnston, Peter R. Newman, Stephanie A. Snedden
Edward Schmidt Publications
We present 88 Hα profiles for 24 pulsating variable stars with periods between 1 and 3 days in order to explore the behavior of this line in type II as compared with classical Cepheids. Surprisingly, large velocity differences were found between Hα and the metal lines in some type II Cepheids. Strong emission was observed in three stars, VZ Aql, NW Lyr, and V439 Oph, while line filling by incipient emission is present in seven others. All of the stars with emission and most with incipient emission belong to Diethelm's AHB2 class, and the emission is associated with the secondary …