- ID:
- ivo://CDS.VizieR/J/A+A/342/773
- Title:
- Hot carbon stars B-V colour excess
- Short Name:
- J/A+A/342/773
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A study of 140 hot carbon and related stars. Table 3 contains our hot carbon stars (HC)-classification (see section 2.2 in the paper) for 119 hot carbon stars and their colour excess E(B-V) as determined by the method described in section 2.3. The analogous data for 21 peculiar stars (RCB variables, AC Her [a RV Tau star], V553 Cen [a class II-Cepheid] etc...) can be found in Table 4: most of them have an oxygen-type classification.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/PASP/115/351
- Title:
- Infrared Southern Cool Carbon Stars
- Short Name:
- J/PASP/115/351
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A large set of deep, near-IR, objective-prism plates taken along the southern Galactic plane was searched for cool supergiants and carbon stars. Accurate coordinates and charts for 759 carbon stars in two Galactic longitude sectors within 7.5{deg} of the plane, 248{deg}<l<288{deg} and 320{deg}<l<341{deg}, are given, including 289 stars not previously published. Many of the new and known stars are found in the IRAS, DENIS, and 2MASS point-source catalogs. The 2MASS colors and the longitude distribution of cool carbon stars are discussed briefly.
- ID:
- ivo://CDS.VizieR/J/AJ/134/214
- Title:
- Infrared study of J-type carbon stars
- Short Name:
- J/AJ/134/214
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We collected 113 J-type carbon stars from the published literature. Observations from 2MASS, IRAS, and ISO show that, except for silicate carbon stars in the J-type carbon star domain, the infrared properties of the other J-type carbon stars are quite similar to those of ordinary carbon stars. The above results imply that the chemical peculiarity of enhanced ^13^C for J-type carbon stars is not reflected in the infrared region. In addition, the possible evolutionary scenario and binarity for J-type carbon stars are also discussed.
- ID:
- ivo://CDS.VizieR/J/A+A/601/A4
- Title:
- IRC+10216 carbon chains mapped with ALMA
- Short Name:
- J/A+A/601/A4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Linear carbon chains are common in various types of astronomical molecular sources. Possible formation mechanisms involve both bottom-up and top-down routes. We have carried out a combined observational and modeling study of the formation of carbon chains in the C-star envelope IRC +10216, where the polymerization of acetylene and hydrogen cyanide induced by ultraviolet photons can drive the formation of linear carbon chains of increasing length. We have used ALMA to map the emission of 3 mm rotational lines of the hydrocarbon radicals C_2_H, C_4_H, and C_6_H, and the CN-containing species CN, C_3_N, HC_3_N, and HC_5_N with an angular resolution of 1". The spatial distribution of all these species is a hollow 5-10" wide spherical shell located at a radius of 10-20" from the star, with no appreciable emission close to the star. Our observations resolve the broad shell of carbon chains into thinner subshells that are 1-2" wide and not fully concentric, indicating that the mass-loss process has been discontinuous and not fully isotropic. The radial distributions of the species mapped reveal subtle differences: while the hydrocarbon radicals have very similar radial distributions, the CN-containing species show more diverse distributions, with HC_3_N appearing earlier in the expansion and the radical CN extending later than the rest of the species. The observed morphology can be rationalized by a chemical model in which the growth of polyynes is mainly produced by rapid gas-phase chemical reactions of C_2_H and C_4_H radicals with unsaturated hydrocarbons, while cyanopolyynes are mainly formed from polyynes in gas-phase reactions with CN and C_3_N radicals.
- ID:
- ivo://CDS.VizieR/J/A+A/574/A56
- Title:
- IRC +10216 17.8GHz-26.3GHz spectrum
- Short Name:
- J/A+A/574/A56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- IRC +10216 is the prototypical carbon star exhibiting an extended molecular circumstellar envelope. Its spectral properties are therefore the template for an entire class of objects. The main goal is to systematically study the 1.3cm spectral line characteristics of IRC +10216. We carried out a spectral line survey with the Effelsberg-100m telescope toward IRC +10216. It covers the frequency range between 17.8GHz and 26.3GHz (K-band). In the circumstellar shell of IRC +10216, we find 78 spectral lines, among which 12 remain unidentified. The identified lines are assigned to 18 different molecules and radicals. A total of 23 lines from species known to exist in this envelope are detected for the first time outside the Solar System and there are additional 20 lines firstly detected in IRC +10216. The potential orgin of U lines is also discussed. Assuming local thermodynamic equilibrium (LTE), we determine rotational temperatures and column densities of 17 detected molecules. Molecular abundances relative to H_2_ are also estimated. A non-LTE analysis of NH_3_ shows that the bulk of its emission arises from the inner envelope with a kinetic temperature of 70+/-20K. Evidence for NH_3_ emitting gas with higher kinetic temperature is also obtained, and potential abundance differences between various ^13^C-bearing isotopologues of HC_5_N are evaluated. Overall, the isotopic ^12^C/^13^C ratio is estimated to be 49+/-9. Finally, a comparison of detected molecules in the 1.3cm range with the dark cloud TMC-1 indicates that silicate bearing molecules are more predominant in IRC +10216.
- ID:
- ivo://CDS.VizieR/J/A+A/606/A74
- Title:
- IRC +10216 13.3GHz-18.5GHz spectrum
- Short Name:
- J/A+A/606/A74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A spectral line survey of IRC +10216 between 13.3 and 18.5GHz was carried out using the Shanghai Tian Ma 65 m Radio Telescope (TMRT-65m) with a sensitivity of <7mK. Thirty-five spectral lines of 12 different molecules and radicals were detected in total. Except for SiS, the detected molecules are all carbon-chain molecules, including HC_3_N, HC_5_N, HC_7_N, HC_9_N, C_6_H, C_6_H^-^, C_8_H, SiC_2_, SiC_4_, c-C_3_H_2_, and l-C_5_H. The presence of rich carbon-bearing molecules is consistent with the identity of IRC +10216 as a carbon-rich asymptotic giant branch (AGB) star. The excitation temperatures and column densities of the observed species are derived by assuming a local thermodynamic equilibrium and homogeneous conditions.
- ID:
- ivo://CDS.VizieR/J/PASP/117/199
- Title:
- IRTS carbon stars
- Short Name:
- J/PASP/117/199
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified 139 cool carbon stars in the near-infrared spectrophotometric survey of the Infrared Telescope in Space (IRTS) from the conspicuous presence of molecular absorption bands at 1.8, 3.1, and 3.8{mu}m. Among them, 14 are new bright (K~4.0-7.0) Carbon stars. We find a trend relating the 3.1{mu}m band strength to the (K-L') color index, which is known to correlate with mass-loss rate. This could be an effect of a relation between the depth of the 3.1{mu}m feature and the degree of development of the extended stellar atmosphere where dust starts to form.
- ID:
- ivo://CDS.VizieR/J/PAZh/30/605
- Title:
- JHKLM photometry for carbon stars
- Short Name:
- J/PAZh/30/605
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- JHKLM photometry for nine carbon Mira stars, 18 carbon semiregular variables and 2 oxygen Mira stars are provided.
- ID:
- ivo://CDS.VizieR/J/A+AS/101/513
- Title:
- JHKLM photometry of C stars
- Short Name:
- J/A+AS/101/513
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present J H K L M photometry for 25 Carbon stars, and 450, 600, 800 and 1100 {mu}m for 12 carbon stars and the S-star W Aql. Carbon stars reside on a different part of the [12-25], [K-L] diagram than O-rich stars. Our work confirms earlier observations and shows this relation to hold up at least [K-L] ~ 8mag.
- ID:
- ivo://CDS.VizieR/J/A+A/227/82
- Title:
- JHKLM photometry of 'IRAS-discovered' stars
- Short Name:
- J/A+A/227/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents results of JHKLM photometry data analysis of 249 southern 'IRAS-discovered' stars, which exhibit an emission feature at 11.3 microns in their low-resolution spectra (class 4n stars). The method of Epchtein et al. (1987A&AS...71...39E) is used to separate oxygen-rich and carbon-rich stars on the basis of their sole NIR and IRAS broad-band fluxes. It is shown that NIR data are necessary to calculate the total IR energy received from IRAS stars and such fundamental parameters as individual mass loss rates. An evolutionary model is developed to match the sequence of stars in color diagrams. It is suggested that the sequence of increasing optical depths might not be an evolutionary sequence, but would rather reflect the termination of a process in which the near-IR index increases very quickly at the beginning and is strongly dependent on the mass loss rate.
