- ID:
- ivo://CDS.VizieR/J/A+A/331/633
- Title:
- IUE spectra of lambda Boo stars
- Short Name:
- J/A+A/331/633
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An analysis of the stars included in the catalogue of {lambda} Bootis stars by Paunzen et al. (1997, Cat. <J/A+AS/123/93>) and which also have IUE observations is presented here. Population I A-F type stars as well as field horizontal branch stars were also included in the analysis. Using line-ratios of carbon to heavier elements (Al and Ni) allows us to establish unambiguous membership criteria for the {lambda} Bootis group.
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- ID:
- ivo://CDS.VizieR/J/ApJ/525/420
- Title:
- UV and optical line variations in {epsilon} Persei
- Short Name:
- J/ApJ/525/420
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The rapid variable star, {epsilon} Per (B0.5 IV-III), displays the largest amplitude profile fluctuations known among the growing number of massive, spectrum-variable stars. Here we present an analysis of a continuous 5 day run of IUE UV spectroscopy, and we show for the first time that the systematic, blue-to-red moving patterns observed in high-quality optical spectra are also present in the UV photospheric lines. We present cross-correlation functions of the individual spectra with that of a narrow-lined standard that produce a high signal-to-noise ratio representation of the blue-to-red moving bump patterns found in individual lines. We then use time series analysis methods to determine the periodic components of the profile variations (after reregistering the spectra to correct for binary motion). There are at least six periods present (ranging from 8.46 to 2.27 hr), and most of these signals are also found in optical line variations observed in 1986 (although the relative amplitudes have changed significantly). Furthermore, analysis of a shorter time series of IUE spectra from 1984 shows that similar periods were present then. We also present H{alpha} and He I 6678 profiles obtained with the Georgia State University Multi-Telescope Telescope, which were made simultaneously with IUE, and we show that the profile variations are essentially identical in the UV and optical ranges.
