- ID:
- ivo://CDS.VizieR/J/A+A/381/32
- Title:
- Galactic Cepheid abundances
- Short Name:
- J/A+A/381/32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File table1 contains information about the program stars and spectra . Note that we also added to our sample two distant Cepheids (TV Cam and YZ Aur) which were previously analyzed by Harris & Pilachowski (1984ApJ...282..655H). File table2 contains relative-to-solar averaged elemental abundances (i.e. [El/H]) for program stars. First column gives the name of the star, other columns list the abundance data for all investigated elements. File tablea1 contains an Appendix table with elemental abundances from individual ions (ions are listed in the first column). For each star the following information is given: relative-to-solar abundance of a given ion (i.e. [M/H]), sigma-value, number of the lines used in analysis, absolute abundance of a given ion (M/H) in the scale where logA(H)=12.00.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/344/1
- Title:
- 22GHz observations of VX Sgr
- Short Name:
- J/MNRAS/344/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used MERLIN to observe 22-GHz H_2_O maser emission from the red supergiant VX Sgr in 1994 and 1999. The masers lie in a region 300-400mas in diameter. The angular size and the velocity distribution of the masers are similar at both epochs, although the total flux density in 1999 is only half of that seen in 1994.
- ID:
- ivo://CDS.VizieR/J/A+A/546/A16
- Title:
- 22-GHz water maser clouds
- Short Name:
- J/A+A/546/A16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cool, evolved stars undergo copious mass loss but the detailed mechanisms and the form in which the matter is returned the ISM are still under debate. We investigated the structure and evolution of the wind at 5 to 50 stellar radii from Asymptotic Giant Branch and Red Supergiant stars.
- ID:
- ivo://CDS.VizieR/J/A+AS/127/251
- Title:
- Giants and supergiants ROSAT data
- Short Name:
- J/A+AS/127/251
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present X-ray data for all late-type (A,F,G,K,M) giants and supergiants (luminosity classes I to III-IV) listed in the Bright Star Catalogue that have been detected in the ROSAT all-sky survey. The selection of the sample stars, the data analysis, the criteria for an accepted match between star and X-ray source, and the determination of X-ray fluxes are described.
- ID:
- ivo://CDS.VizieR/J/A+A/607/A96
- Title:
- HD 166734 ESPRESSO spectra
- Short Name:
- J/A+A/607/A96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- HD 166734 is an eccentric eclipsing binary system composed of two supergiant O-type stars, orbiting with a 34.5-day period. In this rare configuration for such stars, the two objects mainly evolve independently, following single-star evolution so far. This system provides a chance to study the individual parameters of two supergiant massive stars and to derive their real masses. An intensive monitoring was dedicated to HD 166734. We analyzed mid- and high-resolution optical spectra to constrain the orbital parameters of this system. We also studied its light curve for the first time, obtained in the VRI filters. Finally, we disentangled the spectra of the two stars and modeled them with the CMFGEN atmosphere code in order to determine the individual physical parameters. HD 166734 is a O7.5If+O9I(f) binary. We confirm its orbital period but we revise the other orbital parameters. In comparison to what we found in the literature, the system is more eccentric and, now, the hottest and the most luminous component is also the most massive one. The light curve exhibits only one eclipse and its analysis indicates an inclination of 63.0+/-2.7{deg}. The photometric analysis provides us with a good estimation of the luminosities of the stars, and therefore their exact positions in the Hertzsprung-Russell diagram. The evolutionary and the spectroscopic masses show good agreement with the dynamical masses of 39.5M_{sun}_ for the primary and 33.5M_{sun}_ for the secondary, within the uncertainties. The two components are both enriched in helium and in nitrogen and depleted in carbon. In addition, the primary also shows a depletion in oxygen. Their surface abundances are however not different from those derived from single supergiant stars, yielding, for both components, an evolution similar to that
- ID:
- ivo://CDS.VizieR/J/A+A/588/A10
- Title:
- HD 149404 FEROS, Coralie and IUE spectra
- Short Name:
- J/A+A/588/A10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Mass and momentum exchanges in close massive binaries play an important role in their evolution, and produce several observational signatures such as asynchronous rotation and altered chemical compositions, that remain after the stars detach again. We investigated these effects for the detached massive O-star binary HD 149404 (O7.5 If + ON9.7 I, P=9.81-days), which is thought to have experienced a past episode of case A Roche-lobe overflow (RLOF). Using phase-resolved spectroscopy, we performed the disentangling of the optical spectra of the two stars. The reconstructed primary and secondary spectra were then analysed with the CMFGEN model atmosphere code to determine stellar parameters, such as the effective temperatures and surface gravities, and to constrain the chemical composition of the components. We complemented the optical study with the study of IUE spectra, which we compare to the synthetic binary spectra. The properties of the stars were compared to evolutionary models.
- ID:
- ivo://CDS.VizieR/J/A+A/542/L32
- Title:
- HD 202850 HeI and SiII spectra
- Short Name:
- J/A+A/542/L32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photospheric lines of B-type supergiants show variability in their profile shapes. In addition, their widths are much wider than can be accounted for purely by stellar rotation. This excess broadening is often referred to as macroturbulence. Both effects have been linked to stellar oscillations, but B supergiants have not been systematically searched yet for the presence of especially short-term variability caused by stellar pulsations. We have started an observational campaign to investigate the line profile variability of photospheric lines in a sample of Galactic B supergiants. These observations aim to improve our understanding of the physical effects acting in the atmospheres of evolved massive stars.
- ID:
- ivo://CDS.VizieR/J/A+A/441/685
- Title:
- HeI & HeII radial velocities of Sk 160/SMC X-1
- Short Name:
- J/A+A/441/685
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new optical spectroscopy of the eclipsing binary pulsar Sk 160/SMC X-1. From the He I absorption lines, taking heating corrections into account, we determine the radial velocity semi-amplitude of Sk 160 to be 21/8+/-1.8km/s. Assuming Sk 160 fills its Roche-lobe, the inclination angle of the system is i=65.3+/-1.3{deg} and in this case we obtain upper limits for the mass of the neutron star as Mx=1.21+/-0.10M_{sun}_ and for Sk 160 as Mo=16.6+/-0.4M_{sun}.
- ID:
- ivo://CDS.VizieR/J/A+A/546/A105
- Title:
- HR8752 evolving through the void
- Short Name:
- J/A+A/546/A105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The main paper on the hypergiant HR8752 evolving through the void combines observational data from various sources: new spectral data, new and already published (B-V), V data. it also describes a new three-dimensional chebychev interpolating code, and gives information on the temperature calibration for hypergiants, and adds some extra Tables on colour excess and historical context (cf. below). The electronic appendix contains a number of tables, too large for publishing in the paper. In the text and in the appendix, they are referred to as Table Axx, resp. Cxx. We note, however, that tables A1.1 to A1.6 in Section 2 of the main paper are here referred to as tables appena11 to appena16. The observational tables appena11 to appena16, appena2, appena3, appena4 all refer to Section 2 in the main paper, while tables appena5, appena6, appena7, appena8 are used in Section 3 of the main paper. The technical table appenc1 describes the three-dimensional chebychev interpolation method used in Section 2 of the main paper. The second technical table appenc2 describes the (hypergiant) temperature calibration and transformation codes between Mk, Teff, and (B-V) data, used in Section 3 of the main paper. Table appena9 discusses some measured colour excesses (Section 3.3 of the main paper). Table appena10 discusses the possibility of historical context (Section 5.11 of the main paper).
- ID:
- ivo://CDS.VizieR/J/A+A/643/A116
- Title:
- HR study of massive supergiants in Per OB1
- Short Name:
- J/A+A/643/A116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Perseus OB1 association, including the h and chi Persei double cluster, is an interesting laboratory for the investigation of massive star evolution as it hosts one of the most populous groupings of blue and red supergiants (Sgs) in the Galaxy at a moderate distance and extinction. We discuss whether the massive O-type, and blue and red Sg stars located in the Per OB1 region are members of the same population, and examine their binary and runaway status. We gathered a total of 405 high-resolution spectra for 88 suitable candidates around 4.5 deg from the center of the association, and compiled astrometric information from Gaia DR2 for all of them. This was used to investigate membership and identify runaway stars. By obtaining high-precision radial velocity (RV) estimates for all available spectra, we investigated the RV distribution of the global sample (as well as different subsamples) and identified spectroscopic binaries (SBs). Most of the investigated stars belong to a physically linked population located at d=2.5+/-0.4kpc. We identify 79 confirmed or likely members, and 5 member candidates. No important differences are detected in the distribution of parallaxes when stars in h and chi Persei or the full sample are considered. In contrast, most O-type stars seem to be part of a differentiated population in terms of kinematical properties. In particular, the percentage of runaways among them (45%) is considerable higher than for the more evolved targets (which is lower than ~5% in all cases). A similar tendency is also found for the percentage of clearly detected SBs, which already decreases from 15% to 10% when the O star and B Sg samples are compared, respectively, and practically vanishes in the cooler Sgs. Concerning this latter result, our study illustrates the importance of taking the effect of the ubiquitous presence of intrinsic variability in the blue-to-red Sg domain into account to avoid the spurious identification of pulsating stars as SBs. All but 4 stars in our working sample (including 10 O giants/Sgs, 36 B Sgs, 9 B giants, 11 A/F Sgs, and 18 red Sgs) can be considered as part of the same (interrelated) population. However, any further attempt to describe the empirical properties of this sample of massive stars in an evolutionary context must take into account that an important fraction of the O stars is or likely has been part of a binary/multiple system. In addition, some of the other more evolved targets may have also been affected by binary evolution. In this line of argument, it is also interesting to note that the percentage of spectroscopic binaries within the evolved population of massive stars in Per OB1 is lower by a factor 4-5 than in the case of dedicated surveys of O-type stars in other environments that include a much younger population of massive stars.
