- ID:
- ivo://CDS.VizieR/J/MNRAS/394/1338
- Title:
- Stellar effective magnetic fields. II.
- Short Name:
- J/MNRAS/394/1338
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the second catalog of averaged quadratic effective magnetic fields <B_e_> of 1212 main sequence and giant stars, and 11 white dwarfs. Our sample includes a subset of 610 chemically peculiar early-type stars. Some stars in the sample are members of several open clusters. The catalog was derived from measurements of the longitudinal magnetic field strength B_e_ for stars, which were scattered in the published sources.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/420/757
- Title:
- STEREO magnetic chemically peculiar stars
- Short Name:
- J/MNRAS/420/757
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- About 10% of upper main-sequence stars are characterized by the presence of chemical peculiarities, often found together with a structured magnetic field. The atmospheres of most of those chemically peculiar stars present surface spots, leading to photometric variability caused by rotational modulation. The study of the light curves of those stars therefore permits a precise measurement of their rotational period, which is important to study stellar evolution and to plan further detailed observations. We analysed the light curves of 1028 chemically peculiar stars obtained with the STEREO spacecraft. We present here the results obtained for the 337 magnetic chemically peculiar stars in our sample.
- ID:
- ivo://CDS.VizieR/J/MNRAS/429/119
- Title:
- STEREO non-magnetic chemically peculiar stars
- Short Name:
- J/MNRAS/429/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have analysed the photometric data obtained with the STEREO spacecraft for 558 non-magnetic chemically peculiar (CP) stars to search for rotational and pulsational variability. Applying the Lomb-Scargle and the phase dispersion minimization methods, we have detected photometric variability for 44 objects from which 35 were previously unknown. The new objects are all bright stars on the ecliptic plane (magnitude range 4.7<V<11.7) and will therefore be of great interest to studies of stellar structure and evolution. In particular, several show multiple signals consistent with hybrid {delta} Scuti and {gamma} Doradus pulsation, with different periodicities allowing very different regions of the stellar interior to be studied. There are two subgroups of stars in our sample: the cool metallic line Am (CP1) and the hot HgMn (CP3) stars. These objects fall well inside the classical instability strip where {delta} Scuti, {gamma} Doradus and slowly pulsating B-type stars are located. We also expect to find periods correlated to the orbital period for CP1 objects as they are mostly members of binary systems. For CP3 stars, rotationally induced variability is still a matter of debate. Although surface spots were detected, they are believed to produce only marginal photometric amplitudes. So, periods from several hours to a few days were expected for these two star groups. The STEREO/HI-1 data are well matched to studies of this frequency domain, owing to the cadence of approximately 40-min and multiple epochs over four and a half years. The remaining 514 stars are likely to be constant in the investigated range from 0.1 to 10d. In some cases, the presence of blending or systematic effects prevented us from detecting any reliable variability and in those cases we classified the star as constant. We discuss our results in comparison to already published ones and find a very good agreement. Finally, we have calibrated the variable stars in terms of the effective temperature and luminosity in order to estimate masses and ages. For this purpose, we used specifically developed calibrations for CP stars and, when available, Hipparcos parallaxes. All but two objects cover the stellar mass range from 1.5 to 5M_{sun}_ and are located between the zero- and terminal-age main sequence.
- ID:
- ivo://CDS.VizieR/J/AZh/71/588
- Title:
- Study of Two HgMn Stars
- Short Name:
- J/AZh/71/588
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Three spectra of HD182308 (HR 7361) and four spectra of HD178065 (HR 7245) were obtained from 1989 to 1990 with the Main Stellar Spectrograph of the 6-m telescope at the Special Astrophysical Observatory and with the Coude spectrograph of the 2-m telescope of the Rozhen Observatory of the Bulgarian Academy of Sciences. Spectra were obtained in the range of 3700-4900A with inverse dispersion of 9 A/mm. Spectral resolution was close to 0.25A. Elemental abundances of two HgMn stars, HD 178065 and HD 182308, were found. Objects: --------------------------------------- RA (2000) DE Designation(s) --------------------------------------- 19 19 46.03 +64 23 26.7 HD 182308 19 07 08.95 +00 38 29.3 HD 178065 ---------------------------------------
- ID:
- ivo://CDS.VizieR/J/MNRAS/460/1912
- Title:
- The Catalog of HgMn Stars
- Short Name:
- J/MNRAS/460/1912
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To better understand the hot chemically peculiar group of HgMn stars, we have considered a compilation of a large number of recently published data obtained for these stars from spectroscopy. We compare these data to the previous compilation by Smith. We confirm the main trends of the abundance peculiarities, namely the increasing overabundances with increasing atomic number of heavy elements, and their large spread from star to star. For all the measured elements, we have looked for correlations between abundances and effective temperature (T_eff_). In addition to the known correlation for Mn, some other elements are found to show some connection between their abundances and T_eff_. We have also checked if multiplicity is a determinant parameter for abundance peculiarities determined for these stars. A statistical analysis using a Kolmogorov-Smirnov test shows that the abundances anomalies in the atmosphere of HgMn stars do not present significant dependence on the multiplicity.
- ID:
- ivo://CDS.VizieR/J/A+A/339/165
- Title:
- The red spectrum of HD 101065
- Short Name:
- J/A+A/339/165
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Wavelength list for Przybylski's star (a rapidly rotation Ap star) including a measurement of the line depths.
- ID:
- ivo://CDS.VizieR/J/PAZh/27/187
- Title:
- UBV observations of HD 179821
- Short Name:
- J/PAZh/27/187
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The photoelectric and photographic observations of the supergiant HD 179821 with a large infrared excess, a candidate for protoplanetary objects during 1899-1999 are presented.
- ID:
- ivo://CDS.VizieR/J/PAZh/26/705
- Title:
- UBV observations of post-AGB supergiants
- Short Name:
- J/PAZh/26/705
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Systematic UBV observations of six variable post-AGB supergiants in 1991-1999 are presented.
- ID:
- ivo://CDS.VizieR/J/ApJS/123/639
- Title:
- UBV photometry of metal-weak candidates
- Short Name:
- J/ApJS/123/639
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photoelectric UBV photometry for some 2600 metal-poor dwarf and giant candidates selected from the HK objective-prism/interference-filter survey of Beers and colleagues. These data provide the basis for our ultraviolet-excess selection of objects having [Fe/H]{<~}-2.0 for a spectroscopic investigation in which we have obtained ~1-2{AA} resolution spectra of some 1000 objects. The present material may also prove useful for investigations of the metal-poor dwarfs and giants more metal-rich than [Fe/H]=-2.0, as well as the misclassified subdwarf O and B stars, white dwarfs, blue metal-poor stars, and field horizontal-branch stars which appear in the catalog.
- ID:
- ivo://CDS.VizieR/J/A+AS/128/265
- Title:
- ubvy-beta photometry of CP2 stars
- Short Name:
- J/A+AS/128/265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this work is to study the capacity of the uvby H_{beta}_ system for detecting the chemically peculiar (CP) stars based on the effect that peculiar features in the flux distribution have on all the Stroemgren-Crawford indices. Our study focuses on the classical magnetic peculiar stars (CP2), though Am star s (CP1) are also included for comparison with cool CP2 stars. Satisfactory results were obtained for hot CP2 stars: the definition of a new index p, which is a linear combination of uvby H_{beta}_ colours, allowed us to separate a high percentage of hot CP2 stars from normal stars. According to this new index, 60 new CP2 candidates are proposed. The working sample was extracted from The General Catalogue of Ap and Am stars by Renson et al. (1991, Cat. <III/162>). Photometric observations to enlarge the sample of CP2 stars with complete uvby H_{beta}_ photometry were carried out. These observations are also reported in the present paper. The new index p is also used to correct the reddening of early CP2 stars computed as if they were normal stars.
