- ID:
- ivo://CDS.VizieR/J/A+A/507/929
- Title:
- Light curves of SDSS J100658.40+233724.4
- Short Name:
- J/A+A/507/929
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present time-resolved spectroscopy and photometry of SDSS J100658.40+233724.4, which we have discovered to be an eclipsing cataclysmic variable with an orbital period of 0.18591324 days (267.71507min). The observed velocity amplitude of the secondary star is 276+/-7km/s, which an irradiation correction reduces to 258+/-12km/s. Doppler tomography of emission lines from the infrared calcium triplet supports this measurement. We have modelled the light curve using the LCURVE code and Markov Chain Monte Carlo simulations, finding a mass ratio of 0.51+/-0.08. From the velocity amplitude and the light curve analysis we find the mass of the white dwarf to be 0.78+/-0.12M_{sun}_ and the masses and radii of the secondary star to be 0.40+/-0.10M_{sun}_ and 0.466+/-0.036R_{sun}_, respectively. The secondary component is less dense than a normal main sequence star but its properties are in good agreement with the expected values for a CV of this orbital period. By modelling the spectral energy distribution of the system we find a distance of 676+/-40pc and estimate a white dwarf effective temperature of 16500+/-2000K.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/156/6
- Title:
- Light element abundances of RGB & AGB stars in M10
- Short Name:
- J/AJ/156/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CN and CH band measurements for 137 red giant branch (RGB) and asymptotic giant branch (AGB) stars in the Galactic globular cluster M10. Our measurements come from low-resolution spectroscopy taken with the Hydra spectrograph on the WIYN-3.5 m telescope. We use these measurements to identify two populations of stars within the cluster, CN-normal and CN-enhanced, and find that in our sample 60% of stars are CN-enhanced. Our large sample allows us to conduct a detailed analysis on the carbon and nitrogen abundances and the radial distribution of each population separately. Our analysis of the radial dependence shows that each population has the same radial distribution in the cluster, which is likely due to the cluster being dynamically evolved. We also compare our results to other methods of classifying multiple populations in globular clusters such as the Na-O anti-correlation and the HST pseudo-color-magnitude diagrams. We find that these three methods of identifying multiple populations are in good agreement with each other for M10 and all lead to an estimate of the fraction of second-generation stars approximately equal to 60%. Among AGB stars, when classified by the CN band, there appears to be a lack of second-generation stars when compared to the RGB stars. However, when classified by [N/Fe], we find a similar 60% of AGB stars in the second generation. Finally, we use the measured carbon and nitrogen abundances in RGB stars to study the change of each element with magnitude as stars evolve up the RGB, comparing the results to globular clusters of similar metallicity, M3 and M13.
- ID:
- ivo://CDS.VizieR/J/A+A/628/A111
- Title:
- Li in BPS CS22876-032 spectrum
- Short Name:
- J/A+A/628/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-resolution and high-quality UVES spectroscopic data of the metal-poor double-lined spectroscopic binary CS 22876-032 ([Fe/H] approximately -3.7dex). Our goal is to derive the ^6^Li/^7^Li isotopic ratio by analysing the LiI 670.8nm doublet. Methods. We co-added all 28 useful spectra normalised and corrected for radial velocity to the rest frame of the primary star. We fitted the Li profile with a grid of the 3D non-local thermodynamic equilibrium (NLTE) synthetic spectra to take into account the line profile asymmetries induced by stellar convection, and performed Monte Carlo simulations to evaluate the uncertainty of the fit of the Li line profile. We checked that the veiling factor does not affect the derived isotopic ratio, ^6^Li/^7^Li, and only modifies the Li abundance, A(Li), by about 0.15dex. The best fit of the Li profile of the primary star provides A(Li)=2.17+/-0.01dex and ^6^Li/^7^Li=8^+2^_-5_% at 68% confidence level. In addition, we improved the Li abundance of the secondary star at A(Li)=1.55+/-0.04dex, which is about 0.6 dex lower than that of the primary star. The analysis of the Li profile of the primary star is consistent with no detection of ^6^Li and provides an upper limit to the isotopic ratio of ^6^Li/^7^Li<10% at this very low metallicity, about 0.5dex lower in metallicity than previous attempts for detection of ^6^Li in extremely metal poor stars. These results do not solve or worsen the cosmological ^7^Li problem, nor do they support the need for non-standard ^6^Li production in the early Universe.
- ID:
- ivo://CDS.VizieR/J/A+A/531/A25
- Title:
- Linear and circular polarisation spectra of 2 stars
- Short Name:
- J/A+A/531/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The identification of the carriers of diffuse interstellar bands (DIBs) remains one of the long-standing mysteries in astronomy. The detection of a polarisation signal in a DIB profile can be used to distinguish between a dust or gas-phase carrier. The polarisation profile can give additional information on the grain or molecular properties of the absorber. The aim is to measure the polarisation efficiency of the carriers of the diffuse interstellar bands.
- ID:
- ivo://CDS.VizieR/J/A+A/459/317
- Title:
- Line Frequencies for Uracil
- Short Name:
- J/A+A/459/317
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report new laboratory spectroscopic data on the nucleic acid uracil. The dataset has been extended both into the microwave and towards mm-wavelengths with the aim to provide accurate transition rest frequencies for astrophysical searches. The complete experimental linelist used for the analysis of the data is compiled in Table 2. Lines marked with an asterisk are taken from Brown et al. (1988, J. Mol. Struct. 190, 185 and J. Am. Chem. Soc. 110, 2329), all other lines have been measured in this work.
- ID:
- ivo://CDS.VizieR/J/A+A/408/L29
- Title:
- Line identification of HD 34700
- Short Name:
- J/A+A/408/L29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We announce the star HD 34700 to be a double-lined spectroscopic binary, and find it to be a weak-line T Tauri object. The spectra of both components are very similar and both show the Li I feature at 6708{AA}. Strong arguments in favour of the binary nature of the star as opposed to other possibilities are offered. It is very likely that the companion is also a T Tauri star of similar mass. We present, in Table 2, a list of the lines identified and the radial velocities of the two components for three epochs.
- ID:
- ivo://CDS.VizieR/J/A+AS/103/83
- Title:
- Line identifications in a fireball spectrum
- Short Name:
- J/A+AS/103/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 305 emission lines were found in a spectrum of a fireball of -9th magnitude. The identification of most of the lines is given. Also a detailed tracing of the spectrum in the range 3600-6600{AA} is presented. The tracing contains also computed synthetic spectrum and both spectra can be easily compared. The following species were found in the spectrum: Fe I, Na I, Mg I, Al I, Ca I, Ti I, Cr I, Mn I, Ni I, Mg II, Si II, Ca II, Fe II, FeO, probably also Si I, Ba II, C_2_, and possibly V I, Co I, Cu I, Ti II. The presence of other chemical elements in meteor spectra is discussed.
- ID:
- ivo://CDS.VizieR/J/ApJ/621/673
- Title:
- Line indices for 124 early-type galaxies
- Short Name:
- J/ApJ/621/673
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this paper is to set constraints on the epochs of early-type galaxy formation through the "archaeology" of the stellar populations in local galaxies. Using our models of absorption-line indices that account for variable abundance ratios, we derive ages, total metallicities, and element ratios of 124 early-type galaxies in high- and low-density environments. The data are analyzed by comparison with mock galaxy samples created through Monte Carlo simulations taking the typical average observational errors into account, in order to eliminate artifacts caused by correlated errors.
- ID:
- ivo://CDS.VizieR/J/ApJS/210/23
- Title:
- Line intensities in CN transitions
- Short Name:
- J/ApJS/210/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Line strengths have been calculated in the form of Einstein A coefficients and f-values for a large number of bands of the A^2^{Pi}-X^2^{Sigma}^+^ and B^2^{Sigma}^+^-X^2^{Sigma}^+^ systems and rovibrational transitions within the X^2^{Sigma}^+^ state of CN using Western's PGOPHER program. The J dependence of the transition dipole moment matrix elements (the Herman-Wallis effect) has been taken into account. Rydberg-Klein-Rees potential energy functions for the A^2^{Pi}, B^2^{Sigma}^+^, and X^2^{Sigma}^+^ states were computed using spectroscopic constants from the A^2^{Pi}-X^2^{Sigma}^+^ and B^2^{Sigma}^+^-X^2^{Sigma}^+^ transitions. New electronic transition dipole moment functions for these systems and a dipole moment function for the X^2^{Sigma}^+^ state were generated from high level ab initio calculations and have been used in Le Roy's LEVEL program to produce transition dipole moment matrix elements (including their J dependence) for a large number of vibrational bands. The program PGOPHER was used to calculate Einstein A coefficients, and a line list was generated containing the observed and calculated wavenumbers, Einstein A coefficients and f-values for 290 bands of the A^2^{Pi}-X^2^{Sigma}^+^ transition with v'=0-22, v"=0-15, 250 bands of the B^2^{Sigma}^+^-X^2^{Sigma}^+^ transition with v'=0-15, v"=0-15 and 120 bands of the rovibrational transitions within the X^2^{Sigma}^+^ state with v=0-15. The Einstein A coefficients have been used to compute radiative lifetimes of several vibrational levels of the A^2^{Pi} and B^2^{Sigma}^+^ states and the values compared with those available from previous experimental and theoretical studies.
- ID:
- ivo://CDS.VizieR/J/A+A/549/A65
- Title:
- Line intensities of NGC 6803
- Short Name:
- J/A+A/549/A65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the high-dispersion spectra of the elliptical ring shaped planetary nebula NGC 6803, secured with the Hamilton Echelle Spectrograph attached to the 3-m Shane telescope of Lick Observatory. Numerous lines from neutral to quadruply ionized ions are presented in the wavelength region from 3650 to 9900{AA}. We also use the low dispersion UV spectral data obtained with the 60-cm interstellar ultraviolet explorer.
