We have performed the abundance analysis of the cool magnetic CP star HR 8216 (=HD 204411) using ... more We have performed the abundance analysis of the cool magnetic CP star HR 8216 (=HD 204411) using 2.4{AA}/mm Dominion Astrophysical Observatory Reticon exposures covering ll 3830-4770{AA} with a typical signal-to-noise ratio of 200. The spectrograms were measured interactively with the graphics computer program REDUCE. We performed a fine analysis with an ATLAS9 metal-rich model atmosphere whose predictions best matched the
Observations of the mercury-manganese star φ Her with the Navy Prototype Optical Interferometer (... more Observations of the mercury-manganese star φ Her with the Navy Prototype Optical Interferometer (NPOI) conclusively reveal the previously unseen companion in this single-lined binary system. The NPOI data were used to predict a spectral type of A8 V for the secondary star φ Her B. This prediction was subsequently confirmed by spectroscopic observations obtained at the Dominion Astrophysical Observatory. φ Her B is rotating at 50+/-3 km s-1, in contrast to the 8 km s-1 lines of φ Her A. Recognizing the lines from the secondary permits one to separate them from those of the primary. The abundance analysis of φ Her A shows an abundance pattern similar to those of other HgMn stars, with Al being very underabundant and Sc, Cr, Mn, Zn, Ga, Sr, Y, Zr, Ba, Ce, and Hg being very overabundant.
We determined effective temperatures and surface gravities for five MCP stars using ATLAS9 metal-... more We determined effective temperatures and surface gravities for five MCP stars using ATLAS9 metal-rich model atmospheres, optical region spectrophotometry, and Hgamma profiles. The predictions of these models fit the continua significantly better than do those of previous generation ATLAS models. They can even match the 5200A broad, continuum features in three stars where this feature is of moderate strength. A synthesized spectrum of one of these stars, HD 43819, suggests that this feature is at least due partially to differential line blanketing. However, problems remain in fitting the optical region energy distributions of stars with stronger 5200A features. The 4200A and the 6300A features are not reproduced in the models. The relationship between the strength of the 5200A feature and metallicity was also explored using spectrophotometric and photometric indices.
Elemental abundances analysis of the superficially normal stars gamma Ser (F6 V) and 101 Herculis... more Elemental abundances analysis of the superficially normal stars gamma Ser (F6 V) and 101 Herculis (A7 V) consistent with previous studies of this series using photographic region spectrograms obtained with Reticon and CCD detectors produced derived values that are generally solar except for Al which is very underabundant and the rare earths which do not have the solar pattern. Similar discrepancies from solar values are seen in other superficially normal stars of this series with similar temperatures. Our results for gamma Ser are in acceptable agreement with other recent studies based on different techniques and spectral regions. (3 data files).
For all four stars we obtained Dominion Astrophysical Observatory (DAO) 2.4Å/mm SITe-2 or SITe-4 ... more For all four stars we obtained Dominion Astrophysical Observatory (DAO) 2.4Å/mm SITe-2 or SITe-4 CCD spectrograms with a typical signal-to-noise ratio of 200 and a wavelength coverage of 63 or 144Å, respectively. (3 data files).
Elemental abundances of 28 And (A7III) and 99 Her (F7V), which have modest rotational velocities,... more Elemental abundances of 28 And (A7III) and 99 Her (F7V), which have modest rotational velocities, are derived in a manner consistent with previous studies in this series of papers. The values for 28 And, a delta Scuti variable, show that it is slightly metal-poor, but not a classical Am star. 99 Her, which is somewhat more metal-poor, has a rather small microturbulence for its spectral type. (2 data files).
We performed elemental abundances analyses of the mercury-manganese (HgMn) stars 53 Tau, {beta} T... more We performed elemental abundances analyses of the mercury-manganese (HgMn) stars 53 Tau, {beta} Tau, and {gamma} Crv consistent with previous studies of similar stars in this series. (5 data files).
Elemental abundances analysis of the superficially normal B and A stars alpha Dra (A0 III), tau H... more Elemental abundances analysis of the superficially normal B and A stars alpha Dra (A0 III), tau Her (B5 IV), gamma Lyr (B9 III), and HR 7926 (B8 II-III) are performed consistent with previous studies of this series using spectrograms obtained with Reticon and CCD detectors. Comparisons of the first two analysis with those of the same stars performed earlier in this series which used mostly coadded photographic plates show the general consistency of the derived elemental abundances. A slight increase in the adopted effective temperature produces a corresponding increase in the derived abundances. In these stars the He/H ratios are found to be close to solar. Except for gamma Lyr the metals show for the most part marginally subsolar abundance values. But this star has Al, Ca, Sc, and Sr abundances that are substantially underabundant as well as other underabundant values. (2 data files).
We have performed the abundance analysis of the cool magnetic CP star HR 8216 (=HD 204411) using ... more We have performed the abundance analysis of the cool magnetic CP star HR 8216 (=HD 204411) using 2.4{AA}/mm Dominion Astrophysical Observatory Reticon exposures covering ll 3830-4770{AA} with a typical signal-to-noise ratio of 200. The spectrograms were measured interactively with the graphics computer program REDUCE. We performed a fine analysis with an ATLAS9 metal-rich model atmosphere whose predictions best matched the
Observations of the mercury-manganese star φ Her with the Navy Prototype Optical Interferometer (... more Observations of the mercury-manganese star φ Her with the Navy Prototype Optical Interferometer (NPOI) conclusively reveal the previously unseen companion in this single-lined binary system. The NPOI data were used to predict a spectral type of A8 V for the secondary star φ Her B. This prediction was subsequently confirmed by spectroscopic observations obtained at the Dominion Astrophysical Observatory. φ Her B is rotating at 50+/-3 km s-1, in contrast to the 8 km s-1 lines of φ Her A. Recognizing the lines from the secondary permits one to separate them from those of the primary. The abundance analysis of φ Her A shows an abundance pattern similar to those of other HgMn stars, with Al being very underabundant and Sc, Cr, Mn, Zn, Ga, Sr, Y, Zr, Ba, Ce, and Hg being very overabundant.
We determined effective temperatures and surface gravities for five MCP stars using ATLAS9 metal-... more We determined effective temperatures and surface gravities for five MCP stars using ATLAS9 metal-rich model atmospheres, optical region spectrophotometry, and Hgamma profiles. The predictions of these models fit the continua significantly better than do those of previous generation ATLAS models. They can even match the 5200A broad, continuum features in three stars where this feature is of moderate strength. A synthesized spectrum of one of these stars, HD 43819, suggests that this feature is at least due partially to differential line blanketing. However, problems remain in fitting the optical region energy distributions of stars with stronger 5200A features. The 4200A and the 6300A features are not reproduced in the models. The relationship between the strength of the 5200A feature and metallicity was also explored using spectrophotometric and photometric indices.
Elemental abundances analysis of the superficially normal stars gamma Ser (F6 V) and 101 Herculis... more Elemental abundances analysis of the superficially normal stars gamma Ser (F6 V) and 101 Herculis (A7 V) consistent with previous studies of this series using photographic region spectrograms obtained with Reticon and CCD detectors produced derived values that are generally solar except for Al which is very underabundant and the rare earths which do not have the solar pattern. Similar discrepancies from solar values are seen in other superficially normal stars of this series with similar temperatures. Our results for gamma Ser are in acceptable agreement with other recent studies based on different techniques and spectral regions. (3 data files).
For all four stars we obtained Dominion Astrophysical Observatory (DAO) 2.4Å/mm SITe-2 or SITe-4 ... more For all four stars we obtained Dominion Astrophysical Observatory (DAO) 2.4Å/mm SITe-2 or SITe-4 CCD spectrograms with a typical signal-to-noise ratio of 200 and a wavelength coverage of 63 or 144Å, respectively. (3 data files).
Elemental abundances of 28 And (A7III) and 99 Her (F7V), which have modest rotational velocities,... more Elemental abundances of 28 And (A7III) and 99 Her (F7V), which have modest rotational velocities, are derived in a manner consistent with previous studies in this series of papers. The values for 28 And, a delta Scuti variable, show that it is slightly metal-poor, but not a classical Am star. 99 Her, which is somewhat more metal-poor, has a rather small microturbulence for its spectral type. (2 data files).
We performed elemental abundances analyses of the mercury-manganese (HgMn) stars 53 Tau, {beta} T... more We performed elemental abundances analyses of the mercury-manganese (HgMn) stars 53 Tau, {beta} Tau, and {gamma} Crv consistent with previous studies of similar stars in this series. (5 data files).
Elemental abundances analysis of the superficially normal B and A stars alpha Dra (A0 III), tau H... more Elemental abundances analysis of the superficially normal B and A stars alpha Dra (A0 III), tau Her (B5 IV), gamma Lyr (B9 III), and HR 7926 (B8 II-III) are performed consistent with previous studies of this series using spectrograms obtained with Reticon and CCD detectors. Comparisons of the first two analysis with those of the same stars performed earlier in this series which used mostly coadded photographic plates show the general consistency of the derived elemental abundances. A slight increase in the adopted effective temperature produces a corresponding increase in the derived abundances. In these stars the He/H ratios are found to be close to solar. Except for gamma Lyr the metals show for the most part marginally subsolar abundance values. But this star has Al, Ca, Sc, and Sr abundances that are substantially underabundant as well as other underabundant values. (2 data files).
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