- ID:
- ivo://CDS.VizieR/J/A+AS/113/51
- Title:
- Catalogue of associations IRAS and S stars
- Short Name:
- J/A+AS/113/51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cross identifications between the General Catalogue of Galactic S Stars (GCGSS), the IRAS Point Source Catalogue (PSC), and the Guide Star Catalogue (GSC) are presented. The purpose of the present catalogue is i) to provide a clean sample of S stars with far-IR data, and ii) to provide accurate GSC positions for S stars, superseding those listed in the GCGSS. The IRAS colour-colour diagram and the galactic distribution of S stars associated with an IRAS source are presented. Several S stars having extended images in at least one IRAS band have also been identified.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/480/2953
- Title:
- Catalogue of CP stars (HgMn, ApBp, AmFm)
- Short Name:
- J/MNRAS/480/2953
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present a new catalogue of chemically peculiar (CP) stars obtained by compiling publications in which abundances of metals are provided. Our catalogue includes 428 stars for which the data were obtained through spectroscopic observations. Most of them (416) are AmFm, HgMn, and ApBp stars. We have used this compilation to proceed to a statistical overview of the abundance anomalies versus the physical parameters of the stars. Spearman's rank correlation test has been applied, and a significant number of correlations of abundance peculiarities with respect to effective temperature, surface gravity, and rotation velocity have been found. Four interesting cases are discussed in details: the Mn peculiarities in HgMn stars, the Ca correlation with respect to effective temperature in AmFm stars, the case of helium and iron in ApBp stars. Furthermore, we checked for ApBp stars using Anderson-Darling test whether the belonging to a multiple system is a determinant parameter or not for abundance peculiarities.
- ID:
- ivo://CDS.VizieR/J/A+A/407/631
- Title:
- Catalogue of stellar effective magnetic fields
- Short Name:
- J/A+A/407/631
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the catalogue of averaged quadratic effective magnetic fields <B_e_> for 596 main sequence and giant stars. The catalogue is derived from measurements of the stellar effective magnetic field strengths B_e_, which were compiled from the existing literature.
- ID:
- ivo://CDS.VizieR/J/A+A/454/171
- Title:
- CCD {Delta}a-photometry of 8 open clusters
- Short Name:
- J/A+A/454/171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The detection of magnetic chemically peculiar (CP2) stars in open clusters of the Milky Way can be used to study the influence of different galactic environments on the (non-)presence of peculiarities, which has to be taken into account in stellar evolution models. Furthermore it is still unknown if the CP2 phenomenon evolves, i.e. does the strength of the peculiarity feature at 5200{AA} increase or decrease with age. Methods. We have observed eight young to intermediate age open clusters in the {Delta}a photometric system.
- ID:
- ivo://CDS.VizieR/J/A+A/443/157
- Title:
- CCD photometry in 6 open clusters
- Short Name:
- J/A+A/443/157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Within the sample of six young open clusters (NGC 1502, NGC 3105, Stock 16, NGC 6268, NGC 7235 and NGC 7510) we have investigated 1753 objects using the narrow band, three filter Delta a photometric system resulting in the detection of eleven bona-fide magnetic chemically peculiar (CP) stars and five Be or metal-weak stars. The results for the distant cluster NGC 3105 is most important because of the still unknown influence of the global metallicity gradient of the Milky Way. These findings confirms that CP stars are present in open clusters of very young ages (logt>=6.90) at galactocentric distances up to 11.4kpc. For all programme clusters the age, reddening and distance modulus were derived using the corresponding isochrones. Some additional variable stars within Stock 16 could be identified by comparing different photometric studies.
- ID:
- ivo://CDS.VizieR/J/ApJ/747/102
- Title:
- ^12^C/^13^C ratio for 18 galactic R CrB stars
- Short Name:
- J/ApJ/747/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observed spectra of R Coronae Borealis (RCB) and hydrogen-deficient carbon (HdC) stars are analyzed by synthesizing the C_2_ Swan bands (1, 0), (0, 0), and (0, 1) using our detailed line list and the Uppsala model atmospheres. The (0, 1) and (0, 0) C_2_ bands are used to derive the ^12^C abundance, and the (1, 0) ^12^C^13^C band to determine the ^12^C/^13^C ratios. The carbon abundance derived from the C_2_ Swan bands is about the same for the adopted models constructed with different carbon abundances over the range 8.5 (C/He=0.1%) to 10.5 (C/He=10%). Carbon abundances derived from C I lines are about a factor of four lower than the carbon abundance of the adopted model atmosphere over the same C/He interval, as reported by Asplund et al., who dubbed the mismatch between adopted and derived C abundance as the "carbon problem." In principle, the carbon abundances obtained from C_2_ Swan bands and that assumed for the model atmosphere can be equated for a particular choice of C/He that varies from star to star. Then, the carbon problem for C_2_ bands is eliminated. However, such C/He ratios are in general less than those of the extreme helium stars, the seemingly natural relatives to the RCB and HdC stars. A more likely solution to the C_2_ carbon problem may lie in a modification of the model atmosphere's temperature structure. The derived carbon abundances and the ^12^C/^13^C ratios are discussed in light of the double degenerate and the final flash scenarios.
- ID:
- ivo://CDS.VizieR/J/ApJ/897/183
- Title:
- Chemical abundances of 3 stars in Grus II galaxy
- Short Name:
- J/ApJ/897/183
- Date:
- 15 Mar 2022 04:18:06
- Publisher:
- CDS
- Description:
- We present a detailed abundance analysis of the three brightest member stars at the top of the giant branch of the ultrafaint dwarf (UFD) galaxy GrusII. All stars exhibit a higher than expected [Mg/Ca] ratio compared to metal-poor stars in other UFD galaxies and in the Milky Way (MW) halo. Nucleosynthesis in high-mass (>=20M{sun}) core-collapse supernovae has been shown to create this signature. The abundances of this small sample (three) stars suggests the chemical enrichment of GrusII could have occurred through substantial high-mass stellar evolution, and is consistent with the framework of a top-heavy initial mass function. However, with only three stars it cannot be ruled out that the abundance pattern is the result of a stochastic chemical enrichment at early times in the galaxy. The most metal-rich of the three stars also possesses a small enhancement in rapid neutron-capture (r-process) elements. The abundance pattern of the r-process elements in this star matches the scaled r-process pattern of the solar system and r-process enhanced stars in other dwarf galaxies and in the MW halo, hinting at a common origin for these elements across a range of environments. All current proposed astrophysical sites of r-process element production are associated with high- mass stars, thus the possible top-heavy initial mass function of GrusII would increase the likelihood of any of these events occurring. The time delay between the {alpha} and r-process element enrichment of the galaxy favors a neutron star merger as the origin of the r-process elements in GrusII.
- ID:
- ivo://CDS.VizieR/III/58
- Title:
- Chemical elements in peculiar stellar spectra
- Short Name:
- III/58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A systematic search of 27 journals, IAU Symposia, and Colloquia has yielded this catalogue of identifications of chemical species in peculiar spectra Ap, Bp and Am generally. Abundance surveys were only searched if they included element identification lists.
- ID:
- ivo://CDS.VizieR/J/A+A/459/871
- Title:
- Chemically peculiar stars in the LMC
- Short Name:
- J/A+A/459/871
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high precision photometric Delta a observations of 417 objects in NGC 2136/7 and its surrounding field, of which five turned out to be bona fide magnetic CP stars. In addition, we discovered two Be/Ae stars. This intermediate band photometric system samples the depth of the 520nm flux depression by comparing the flux at the center with the adjacent regions with bandwidths of 11nm to 23nm. The Delta a photometric system is most suitable for detecting CP2 stars with high efficiency, but is also capable of detecting a small percentage of non-magnetic CP objects. From our investigations of NGC 1711, NGC 1866, NGC 2136/7, their surroundings, and one independent field of the LMC population, we derive an occurrence of classical chemically peculiar stars of 2.2(6)% in the LMC, which is only half the value found in the Milky Way. The mass and age distribution of the photometrically detected CP stars is not different from that of similar objects in galactic open clusters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/487/5922
- Title:
- CP stars catalog (roAp, He-weak, He-rich)
- Short Name:
- J/MNRAS/487/5922
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To enlarge our data base of chemically peculiar stars, we compiled published data concerning the He-weak and He-rich stars observed by high-resolution spectroscopy techniques during last decades. Twenty He-weak and 28 He-rich stars have been added to the data base. We have also distinguished roAp stars from stars previously identified as Ap stars. To deepen our knowledge on statistical overview of the abundance anomalies versus the physical parameters of stars, we compared our data with previous compilations. We applied statistical tests on our data and found interesting correlations for effective temperature and surface gravity for all type of stars and a few correlations for projected rotation velocity only for He-rich stars. Because of the lack of the data, we could not check whether being a member of binary system is affecting on chemical peculiarities of those stars.