- ID:
- ivo://CDS.VizieR/III/2
- Title:
- Preliminary Catalog Early-Type Emission Stars
- Short Name:
- III/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The present catalogue presents a list of 3216 stars mostly earlier than type F which have shown emission features and specifically one or more lines of the Balmer series in emission. It is a compilation and rearrangement of the following lists: * the Catalogue and Bibliography of Stars of Classes B and A whose spectra have bright H lines by P. Merrill and C. Burwell, * the lists of Haro and his associates at Tonantzintla, * the catalogues of Luminous Stars in the Northern Milky Way, Vols. I to VI published by the astronomers of the Hamburger Sternwarte and the Warner and Swasey Observatoryy (III/76) * shorter lists of emission stars published by Parenago, Bidelman and McCarthy and Treanor have also been included. The present catalogue has a simple aim: to assist the astronomer in finding from a vast array of articles in the literature whether the star under investigation has been known to show emission features in the earlier major surveys of emission stars of early type carried out at the Mount Wilson, Tonantzila, Hamburg and Warner-Swasey Observatories. The catalogue includes the star identification, Durchmusterung identification, source catalog, RA and Dec, Galactic latitude and longitude, apparent magnitude, spectral classification and remarks.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/896/24
- Title:
- Properties of atomic lines in 51 Oph UV spectra
- Short Name:
- J/ApJ/896/24
- Date:
- 07 Mar 2022 13:24:57
- Publisher:
- CDS
- Description:
- We measured 304 absorption features in the ultraviolet and visible spectra of the star 51 Oph, which is known to have a debris disk with a high inclination. We analyzed the relative populations of atoms in excited fine-structure and metastable levels that are maintained by optical pumping and collisional excitation by electrons, and we found that most of the gas is situated at about 6 au from the star, has an electron volume density 10^5^<n(e)<3x10^6^cm^-3^, and a temperature T=8000K. Our interpretations reveal that the gas is partly ionized, has a column density of neutral hydrogen equal to 10^21^cm^-2^, and has a composition similar to that of a mildly depleted interstellar medium or that of Jupiter-family comets. Compared to results for disks around some other stars, such as {beta} Pic and 49 Cet, we find surprisingly little neutral carbon. No molecular features were detected, which indicates that our line of sight misses the molecule-rich central plane of the disk. The tilt of the disk is also validated by our being able to detect resonant scattering of the starlight by oxygen atoms.
- ID:
- ivo://CDS.VizieR/J/AJ/144/158
- Title:
- Properties of B and Be stars in h and {chi} Persei
- Short Name:
- J/AJ/144/158
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the B and Be star populations of the double cluster h and {chi} Persei. Blue optical spectroscopy is used to first measure projected rotational velocity, vsini, effective surface temperature, T_eff_, and surface gravity, logg, for B-type sample stars, while available Stromgren photometry is used to calculate T_eff_ and logg for the Be stars showing emission. In our sample of 104 objects for which we measured these stellar parameters, 28 are known or proposed Be stars. Of these Be stars, 22 show evidence of emission at the times of our observations, and furthermore, we find evidence in our data and the literature for at least 8 transient Be stars in the clusters. We find that the Be stars are not rotating near their critical velocity, contrary to the results of studies of similar open clusters. We compare the results of our analysis with other previous studies and find that the cluster members are more evolved than found by Huang & Gies but still retain much of their initial rotational angular momentum.
- ID:
- ivo://CDS.VizieR/J/A+A/506/143
- Title:
- Pulsations of HD 181231
- Short Name:
- J/A+A/506/143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- HD181231 is a B5IVe star, which has been observed with the CoRoT satellite during ~5 consecutive months and simultaneously from the ground in spectroscopy and spectropolarimetry. By analysing these data, we aim to detect and characterize as many pulsation frequencies as possible, to search for the presence of beating effects possibly at the origin of the Be phenomenon. Our results will also provide a basis for seismic modelling. The fundamental parameters of the star are determined from spectral fitting and from the study of the circumstellar emission. The CoRoT photometric data and ground-based spectroscopy are analysed using several Fourier techniques: Clean-ng, Pasper, and Tisaft, as well as a time-frequency technique. A search for a magnetic field is performed by applying the LSD technique to the spectropolarimetric data.
- ID:
- ivo://CDS.VizieR/J/ApJ/766/119
- Title:
- Radial velocities of {delta} Sco
- Short Name:
- J/ApJ/766/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the results of the world-wide observing campaign of the highly eccentric Be binary system {delta} Scorpii 2011 periastron passage which involved professional and amateur astronomers. Our spectroscopic observations provided a precise measurement of the system orbital period at 10.8092+/-0.0005yr. Fitting of the HeII 4686{AA} line radial velocity curve determined the periastron passage time on 2011 July 3, UT 9:20 with a 0.9-day uncertainty. Both these results are in a very good agreement with recent findings from interferometry. We also derived new evolutionary masses of the binary components (13 and 8.2M_{sun}_) and a new distance of 136pc from the Sun, consistent with the HIPPARCOS parallax. The radial velocity and profile variations observed in the H{alpha} line near the 2011 periastron reflected the interaction of the secondary component and the circumstellar disk around the primary component. Using these data, we estimated a disk radius of 150R_{sun}_. Our analysis of the radial velocity variations measured during the periastron passage time in 2000 and 2011 along with those measured during the 20th century, the high eccentricity of the system, and the presence of a bow shock-like structure around it suggest that {delta} Sco might be a runaway triple system. The third component should be external to the known binary and move on an elliptical orbit that is tilted by at least 40{deg} with respect to the binary orbital plane for such a system to be stable and responsible for the observed long-term radial velocity variations.
- ID:
- ivo://CDS.VizieR/J/A+A/537/A59
- Title:
- Radial velocities of gamma Cas
- Short Name:
- J/A+A/537/A59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A detailed analysis of more than 800 electronic high-resolution spectra of gamma Cas, which were obtained during a time interval of over 6000 days (16.84yr) at several observatories, documents the smooth variations in the density and/or extend of its circumstellar envelope. We found a clear anticorrelation between the peak intensity and FWHM of the H{alpha} emission, which seems to agree with recent models of such emission lines.
- ID:
- ivo://CDS.VizieR/J/ApJ/828/47
- Title:
- Radial velocities of the Be star HR 2142
- Short Name:
- J/ApJ/828/47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic investigation of the Be+sdO binary system HR 2142 that is based upon large sets of ultraviolet observations from the International Ultraviolet Explorer (IUE) and ground-based H{alpha} observations. We measured radial velocities for the Be star component from these spectra and computed a revised orbit. In order to search for the spectral signature of the hot subdwarf, we cross-correlated the short wavelength end of each IUE spectrum with a model hot star spectrum, and then we used the predicted Doppler shifts of the subdwarf to shift-and-add all the cross-correlation functions to the frame of the subdwarf. This merged function shows the weak signal from the spectral lines of the hot star, and a best fit is obtained with a mass ratio M_2_/M_1_=0.07+/-0.02, companion temperature T_eff_>=43+/-5kK, projected rotational velocity Vsini<30km/s, and a monochromatic flux ratio near 1170{AA} of f_2_/f_1_>0.009+/-0.001. This hot subdwarf creates a one-armed spiral, tidal wake in the disk of the Be star, and we present a circumbinary disk model that can explain the occurrence of shell absorption lines by gas enhancements that occur where gas crossing the gap created by the subdwarf strikes the disk boundaries. The faint companion of HR 2142 may be representative of a significant fraction of Be stars with undetected former mass donor companion stars.
- ID:
- ivo://CDS.VizieR/J/A+A/459/849
- Title:
- Radial velocities of ups Sgr
- Short Name:
- J/A+A/459/849
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Binaries observed in the initial rapid phase of mass exchange between the components are very rare since the statistical probability of finding them is low. At the same time, thorough studies of them are extremely important for better understanding the process of large-scale mass exchange and possible mass loss from the system. One of these objects is probably upsilon Sgr. By analyzing 35 new electronic spectra and numerous published spectral and photometric observations, we derived the new orbital elements, an upper limit to a secular period change, and also the peculiar RV curve of the blue-shifted H{alpha} absorption. Possible models of the binary and its evolutionary stage are then discussed critically.
- ID:
- ivo://CDS.VizieR/VI/57
- Title:
- Radii of Be star line emitting regions
- Short Name:
- VI/57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This bibliographic catalogue lists radii of line emitting regions around more than 100 Be stars determined from high signal to noise registrations of emission line profiles, listed in nine papers.
- ID:
- ivo://CDS.VizieR/J/A+A/294/135
- Title:
- Rapid variations of Eta Cen
- Short Name:
- J/A+A/294/135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
