- ID:
- ivo://CDS.VizieR/III/27A
- Title:
- Abundances of late G/K dwarfs in solar neighborhood
- Short Name:
- III/27A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this investigation, a technique developed by Spinrad and Taylor for obtaining metal abundances of late-type stars, and used by them in an earlier investigation of evolved stars (see Cat. II/47), is applied to field dwarfs in the solar vicinity and to the Hyades. The colors determined from photoelectric spectrum-scanner observations are listed in the "raw_data.dat" file; the derived blocking factors are given in the "blocking.dat" file. These results were published as the Table 5 of the paper.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/472/2085
- Title:
- ALHAMBRA fields type-I AGN with ELDAR
- Short Name:
- J/MNRAS/472/2085
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ELDAR, a new method that exploits the potential of medium- and narrow-band filter surveys to securely identify active galactic nuclei (AGN) and determine their redshifts. Our methodology improves on traditional approaches by looking for AGN emission lines expected to be identified against the continuum, thanks to the width of the filters. To assess its performance, we apply ELDAR to the data of the ALHAMBRA survey, which covered an effective area of 2.38deg^2^ with 20 contiguous medium-band optical filters down to F814W=24.5. Using two different configurations of ELDAR in which we require the detection of at least 2 and 3 emission lines, respectively, we extract two catalogues of type-I AGN. The first is composed of 585 sources (79% of them spectroscopically-unknown) down to F814W=22.5 at z_phot_>1, which corresponds to a surface density of 209 deg-2. In the second, the 494 selected sources (83% of them spectroscopically-unknown) reach F814W=23 at z_phot_>1.5, for a corresponding number density of 176deg^-2^. Then, using samples of spectroscopically-known AGN in the ALHAMBRA fields, for the two catalogues we estimate a completeness of 73% and 67%, and a redshift precision of 1.01% and 0.86% (with outliers fractions of 8.1% and 5.8%). At z>2, where our selection performs best, we reach 85% and 77% completeness and we find no contamination from galaxies.
- ID:
- ivo://CDS.VizieR/III/92
- Title:
- A Library of Stellar Spectra
- Short Name:
- III/92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The machine-readable version of the library contains digital spectra of 161 stars of spectral types O through M and luminosity classes I, III, and V. Most stars are of solar metallicity, although two were chosen specifically for low metallicity. The data were obtained with the Intensified Reticon Scanner on the #1 91-cm telescope at Kitt Peak National Observatory. The scans cover the wavelength range 3510-7427 angstroms, with a resolution of approximately 4.5 angstroms, while the typical photometric uncertainty of each resolution element is about 1 percent and broadband variations are < 3 percent.
- ID:
- ivo://CDS.VizieR/VI/135
- Title:
- All-sky spectrally matched Tycho2 stars
- Short Name:
- VI/135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present fitted UBVRI-ZY and u'g'r'i'z' magnitudes, spectral types, and distances for 2.4 million stars, derived from synthetic photometry of a library spectrum that best matches the Tycho2 BTVT, NOMAD RN, and 2MASS JHK2/S catalog magnitudes. We present similarly synthesized multifilter magnitudes, types, and distances for 4.8 million stars with 2MASS and SDSS photometry to g<16 within the Sloan survey region, for Landolt and Sloan primary standards, and for Sloan northern (photometric telescope) and southern secondary standards.
- ID:
- ivo://CDS.VizieR/III/153
- Title:
- An Atlas of Near Infrared Stellar Spectra
- Short Name:
- III/153
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The atlas represents a collection of spectra in the wavelength range 2.00 to 2.45 micrometers having a resolution of approximately 0.02 micrometers. The sample of 73 stars includes a supergiant, giants, dwarfs, and subdwarfs with a chemical abundance range of about -2 to +0.5 dex.
- ID:
- ivo://CDS.VizieR/III/166
- Title:
- A New Library of Optical Spectra
- Short Name:
- III/166
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Silva and Cornell have compiled a new digital optical stellar spectra library, consisting of intensities at 5A intervals between 3510A and 8930A for 72 different spectral types. These types range from O to M and luminosities range from I to V. Some weak-line and strong-line spectra are also included. The intensities are in ergs/A, normalized to 100 at 5450A.
- ID:
- ivo://CDS.VizieR/III/44
- Title:
- Atlas of Stellar Spectra
- Short Name:
- III/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- There are exactly 8192 spectral elements (points) in each spectrum, regularly spaced in terms of frequency. The first point corresponds to spectral frequency 0, while point number 8193 (not included) corresponds to the laser frequency. The 632.8nm laser frequency was doubled, producing an effective laser wavelength of about 316.4nm. Tentatively, it may be assumed that the exact laser wavelength is 316.43nm. The spectra have been normalized so that the bluest stars are approximately level from 480 to 1000nm. The spectra are linear in intensity with zero intensity at tabulated zero. It was not possible to make satisfactory atmospheric extinction corrections throughout all of the atmospheric bands; at places where corrections could not be made, the spectra were set (exactly) to zero. Some of these spectra have been published already (H.L. Johnson, Rev. Mex. Astron. Astrof. 2, 71, 1977); the remainder will be published soon (Rev. Mex. Astron. Astrofis., 4, 3). These published spectral plots contain in graphical form the information needed to evaluate the signal-to-noise ratios of the spectra on this tape. (From Harold L. Johnson, Dec. 13, 1977)
- ID:
- ivo://CDS.VizieR/J/AJ/112/628
- Title:
- BATC Color Survey of M67
- Short Name:
- J/AJ/112/628
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The authors present nine color CCD intermediate-band spectrophotometry of a two square degree field centered on the old open cluster M67, from 3890 Angstroms to nearly 1 micron. These observations are taken as a part of the BATC (Beijing-Arizona-Taipei-Connecticut) Color Survey of the Sky, for both scientific and calibration reasons. The BATC program uses a dedicated 60/90 cm Schmidt telecope with a 2048 x 2048 CCD and 15 specially-designed intermediate-band filters to be applied to both galactic and extragalactic studies. Nine-band spectrophotometry of 6558 stars is presented.
- ID:
- ivo://CDS.VizieR/J/A+A/610/A30
- Title:
- B stars in 4 open clusters
- Short Name:
- J/A+A/610/A30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stellar physical properties of star clusters are poorly known and the cluster parameters are often very uncertain. Our goals are to perform a spectrophotometric study of the B star population in open clusters to derive accurate stellar parameters, search for the presence of circumstellar envelopes, and discuss the characteristics of these stars. The BCD spectrophotometric system is a powerful method to obtain stellar fundamental parameters from direct measurements of the Balmer discontinuity. To this end, we wrote the interactive code MIDE3700. The BCD parameters can also be used to infer the main properties of open clusters: distance modulus, color excess, and age. Furthermore, we inspected the Balmer discontinuity to provide evidence for the presence of circumstellar disks and identify Be star candidates. We used an additional set of high-resolution spectra in the H{alpha} region to confirm the Be nature of these stars. We provide Teff, logg, Mv, Mbol, and spectral types for a sample of 68 stars in the field of the open clusters NGC6087, NGC6250, NGC6383, and NGC6530, as well as the cluster distances, ages, and reddening. Then, based on a sample of 230 B stars in the direction of the 11 open clusters studied along this series of three papers, we report 6 new Be stars, 4 blue straggler candidates, and 15 B-type stars (called Bdd) with a double Balmer discontinuity, which indicates the presence of circumstellar envelopes. We discuss the distribution of the fraction of B, Be, and Bdd star cluster members per spectral subtype. The majority of the Be stars are dwarfs and present a maximum at the spectral type B2-B4 in young and intermediate-age open clusters (<40Myr). Another maximum of Be stars is observed at the spectral type B6-B8 in open clusters older than 40Myr, where the population of Bdd stars also becomes relevant. The Bdd stars seem to be in a passive emission phase. Our results support previous statements that the Be phenomenon is present along the whole main sequence band and occurs in very different evolutionary states.We find clear evidence of an increase of stars with circumstellar envelopes with cluster age. The Be phenomenon reaches its maximum in clusters of intermediate age (10-40Myr) and the number of B stars with circumstellar envelopes (Be plus Bdd stars) is also high for the older clusters (40-100Myr).
- ID:
- ivo://CDS.VizieR/J/A+A/539/A129
- Title:
- BVRI light curves of 3 eclipsing binaries
- Short Name:
- J/A+A/539/A129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to derive the absolute parameters of the components of AD And, AL Cam, and V338 Her, interpret their orbital period changes and discuss their evolutionary status. New and complete multi-filter light curves of the eclipsing binaries AD And, AL Cam, and V338 Her were obtained and analysed with modern methods. Using all reliably observed times of minimum light, we examined orbital period irregularities using the least squares method. In addition, we acquired new spectroscopic observations during the secondary eclipses for AL Cam and V338 Her. For AL Cam and V338 Her, we derive reliable spectral types for their primary stars. Statistical checks of orbital period analysis for all systems are very reassuring in the cases of V338 Her and AD And, although less so for AL Cam. The LIght-Time Effect (LITE) results are checked by inclusion of a third light option in the photometric analyses. Light curve solutions provide the means to calculate the absolute parameters of the components of the systems and reliably estimate their present evolutionary status. AL Cam and V338 Her are confirmed as classical Algols of relatively low mass in similar configurations. Unlike AL Cam, however, V338 Her is still transferring matter between its components, raising interest in the determinability of the evolutionary histories of Algols. AD And is found to be a detached system in which both close stars are of age 10^9^yr and is probably a "non-classical" young triple, at an interesting stage of its dynamical evolution.
