- ID:
- ivo://CDS.VizieR/J/AJ/153/174
- Title:
- SDSS-III/APOGEE. II. The multi-epoch ABE sample
- Short Name:
- J/AJ/153/174
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the H-band spectral variability of classical Be stars observed over the course of the Apache Point Galactic Evolution Experiment (APOGEE), one of four subsurveys comprising SDSS-III. As described in the first paper of this series, the APOGEE B-type emission-line (ABE) star sample was culled from the large number of blue stars observed as telluric standards during APOGEE observations. In this paper, we explore the multi-epoch ABE sample, consisting of 1100 spectra for 213 stars. These "snapshots" of the circumstellar disk activity have revealed a wealth of temporal variability including, but not limited to, gradual disappearance of the line emission and vice versa over both short and long timescales. Other forms of variability include variation in emission strength, emission peak intensity ratios, and emission peak separations. We also analyze radial velocities (RVs) of the emission lines for a subsample of 162 stars with sufficiently strong features, and we discuss on a case-by-case basis whether the RV variability exhibited by some stars is caused by binary motion versus dynamical processes in the circumstellar disks. Ten systems are identified as convincing candidates for binary Be stars with as of yet undetected companions.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/311/741
- Title:
- SMC emission-line objects
- Short Name:
- J/MNRAS/311/741
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- H{alpha} and [OIII] narrow-band, wide-field (7x7deg^2^), CCD images of the Small Magellanic Cloud were compared, and a catalogue of candidate planetary nebulae and H{alpha} emission-line stars was compiled. The catalogue contains 131 planetary nebulae candidates, 23 of which are already known to be or are probable planetary nebulae or very low excitation objects. Also, 218 emission-line candidates have been identified, with 113 already known. Our catalogue therefore provides a useful supplement to those of Meyssonnier & Azzopardi (1993, Cat. <J/A+AS/102/451>) and Sanduleak, MacConnell & Davis Phillip (1978PASP...90..621S). Further observations are required to confirm the identity of the unknown objects.
- ID:
- ivo://CDS.VizieR/J/A+A/380/609
- Title:
- Southern emission-line stars multiphotometry
- Short Name:
- J/A+A/380/609
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents a catalogue of previously unpublished optical and infrared photometry for a sample of 162 emission-line objects and shell stars visible from the southern hemisphere. The data were obtained between 1978 and 1997 in the Walraven (WULBV), Johnson/Cousins UBV(RI)_c_ and ESO and SAAO near-infrared (JHKLM) photometric systems. Most of the observed objects are Herbig Ae/Be (HAeBe) stars or HAeBe candidates appearing in the list of HAeBe candidates of The et al. (1994, Cat. <J/A+AS/104/315>), although several B[e] stars, LBVs and T Tauri are also included in the sample. For many of the stars the data presented here are the first photo-electric measurements in the literature. The resulting catalogue consists of 1809 photometric measurements. Optical variability was detected in 66 out of the 116 sources that were observed more than once. 15 out of the 50 stars observed multiple times in the infrared showed variability at 2.2 microns (K band). Table 1 contains the stars identifiers, positions, types and a summary of the observational data on each star. Tables 2, 3 and 4 contain all obtained photometry in the Walraven WULBV, Johnson/Cousins UBV(RI)_c and ESO and SAAO near-infrared (JHKLM) photometric systems.
- ID:
- ivo://CDS.VizieR/J/A+A/620/A145
- Title:
- Space photometry of the Be stars nu Pup
- Short Name:
- J/A+A/620/A145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometry of the bright Be star {nu} Puppis. The observations were obtained with the Solar Mass Ejection Imager (SMEI) and BRITE-Constellation satellites. Several closely but probably not perfectly evenly spaced frequencies are found that are attributed to nonradial pulsations.
- ID:
- ivo://CDS.VizieR/J/A+A/547/A85
- Title:
- Spectra of 7 H{alpha} emission line stars in MBM 18
- Short Name:
- J/A+A/547/A85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate star formation in translucent, high-latitude clouds. Our aim is to understand the star-formation history and rate in the solar neighbourhood. We used spectroscopic observations of newly found candidate H{alpha} emission-line stars to establish their pre-main-sequence nature. The environment was studied through molecular line observations of the cloud (MBM 18/LDN 1569) in which the stars are presumably embedded.
- ID:
- ivo://CDS.VizieR/J/A+A/477/877
- Title:
- Spectroscopic analysis of RJHA 49 and SS73 21
- Short Name:
- J/A+A/477/877
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the spectra and the evolutionary stages of two peculiar emission-line stars: RJHA 49 and SS73 21. We used low and high resolution optical data. Line identifications and measurements were performed for several features in their spectra.
- ID:
- ivo://CDS.VizieR/J/AZh/71/572
- Title:
- Spectroscopic observations of V380 Ori
- Short Name:
- J/AZh/71/572
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of spectral observations of the Ae/Be star V380 Ori in the optical and near-IR ranges for 1976 to 1991, are presented. The spectra were obtained on various telescopes and spectrographs including the Main Stellar Spectrograph of the BTA six-meter telescope. For 270 bright emission lines, the intensities, equivalent widths, half-widths, radial velocities, and variability amplitudes are given.
- ID:
- ivo://CDS.VizieR/J/A+AS/131/479
- Title:
- Spectroscopy of MWC 297
- Short Name:
- J/A+AS/131/479
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- On the basis of spectroscopic CCD material obtained at the Haute Provence Observatory, we provide line identifications and equivalent width measurements in the wavelength region 4100-8900{AA} of the spectrum of MWC 297. About two hundred features are identified, almost exclusively emission lines. Only one interstellar feature could be identified ({lambda}6613) a fact which contrasts with the eigth magnitudes of extinction found by photometrists. The spectrum of the underlying star corresponds probably to a late O or early B-type object. The cooler emission lines correspond to a spectrum of a middle A-type star. Analogies with other stars observed in this series of papers are examined.
- ID:
- ivo://CDS.VizieR/J/A+AS/120/99
- Title:
- Spectroscopy of MWC 645
- Short Name:
- J/A+AS/120/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyse spectroscopic CCD material obtained at the Haute Provence Observatory. We provide identifications and equivalent width measurements in the wavelength region 3740-8790. About 350 emissions lines were measured and about 88 of them were identified. A comparison of our results with those of other authors is provided, as well as a table of elements identified in the spectrum of this star. The pattern of elements present is analogous to that of a late B-type star, but some exceptions are noted, such as the absence of Ne and Mg lines and the presence of K, Cu and Zr lines which appear usually in later type stars. We review the little which is known concerning this object and we also present a quantitative account of the variations in equivalent widths. The observations indicate that the spectrum is highly variable, so that in two different years only half of the lines appear on both spectra. Furthermore variations by at least a factor of two in the equivalent widths are present in many lines. The radial velocity derived from the emission lines (-76km/s) corresponds to that of the shell which probably has a velocity of about 50km/s with respect to the underlying star.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A113
- Title:
- Spectrum of VY CMa in 220.65-224.25GHz range
- Short Name:
- J/A+A/551/A113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the first detection of pure rotational transitions of TiO and TiO2 at (sub-)millimeter wavelengths towards the red supergiant VYCMa. A rotational temperature, Trot, of about 250K was derived for TiO2. Although Trot was not well constrained for TiO, it is likely somewhat higher than that of TiO2. The detection of the Ti oxides confirms that they are formed in the circumstellar envelopes of cool oxygen-rich stars and may be the "seeds" of inorganic-dust formation, but alternative explanations for our observation of TiO and TiO2 in the cooler regions of the envelope cannot be ruled out at this time. The observations suggest that a significant fraction of the oxides is not converted to dust, but instead remains in the gas phase throughout the outflow.
