- ID:
- ivo://CDS.VizieR/J/ApJS/161/118
- Title:
- byH{alpha} photometry in open clusters
- Short Name:
- J/ApJS/161/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Be stars are a class of rapidly rotating B stars with circumstellar disks that cause Balmer and other line emission. There are three possible reasons for the rapid rotation of Be stars: they may have been born as rapid rotators, spun up by binary mass transfer, or spun up during the main-sequence (MS) evolution of B stars. To test the various formation scenarios, we have conducted a photometric survey of 55 open clusters in the southern sky. Of these, five clusters are probably not physically associated groups and our results for two other clusters are not reliable, but we identify 52 definite Be stars and an additional 129 Be candidates in the remaining clusters.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+AS/108/611
- Title:
- CaII & MgII data base
- Short Name:
- J/A+AS/108/611
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/MNRAS/466/163
- Title:
- Candidate Halpha sources in GBS
- Short Name:
- J/MNRAS/466/163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of candidate Halpha emission and absorption line sources and blue objects in the Galactic Bulge Survey (GBS) region. We use a point source catalogue of the GBS fields (two strips of (lxb)=(6{deg}x1{deg}) centred at b=1.5{deg} above and below the Galactic centre), covering the magnitude range 16>=r'>=22.5. We utilize (r'-i', r'-Halpha) colour-colour diagrams to select Halpha emission and absorption line candidates, and also identify blue objects (compared to field stars) using the r'-i' colour index. We identify 1337 Halpha emission line candidates and 336 Halpha absorption line candidates. These catalogues likely contain a plethora of sources, ranging from active (binary) stars, early-type emission line objects, cataclysmic variables (CVs) and low-mass X-ray binaries (LMXBs) to background active galactic nuclei (AGN). The 389 blue objects we identify are likely systems containing a compact object, such as CVs, planetary nebulae and LMXBs. Hot subluminous dwarfs (sdO/B stars) are also expected to be found as blue outliers. Crossmatching our outliers with the GBS X-ray catalogue yields sixteen sources, including seven (magnetic) CVs and one qLMXB candidate among the emission line candidates, and one background AGN for the absorption line candidates. One of the blue outliers is a high state AM CVn system. Spectroscopic observations combined with the multi-wavelength coverage of this area, including X-ray, ultraviolet and (time-resolved) optical and infrared observations, can be used to further constrain the nature of individual sources.
- ID:
- ivo://CDS.VizieR/J/ApJ/408/305
- Title:
- Cat of Stellar Lyman-Alpha Fluxes
- Short Name:
- J/ApJ/408/305
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The data file gives the measured Lyman alpha flux or upper limits for 275 stars as derived from IUE spectra. The file is a subset of Table 1 of Landsman and Simon in that when a star had multiple measurements, only the best measurement is included in this table. The spectral types, V and B-V magnitudes in the table are culled from various sources as described in the paper. Most of the measurements are derived from low-dispersion spectra, and those derived from high-dispersion spectra are flagged. Each measurement was assigned a data quality code according to the signal to noise after removal of the diffuse Lyman alpha background emission. -1 - upper limit 1 - good quality 2 - fair quality 3 - poor quality 4 - contains saturated pixels The final column gives the ratio of the Ly alpha flux to the total bolometric flux of the star, determined as described in the paper. A roundoff was applied to the fluxes listed here to give the fluxes listed in Table 1 of Landsman and Simon.
- ID:
- ivo://CDS.VizieR/V/76
- Title:
- Chromospherically Active Binaries
- Short Name:
- V/76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains 206 spectroscopic binary systems with at least one late-type component that shows Ca II H and K emission in its spectrum. These systems include the classical RS CVn binaries and BY Dra binaries. The catalog summarizes information on the photometric, spectroscopic, orbital, and physical properties of the systems as well as space motions and positions. Up to 42 "parameters" for each stellar system are listed followed by the appropriate reference to direct interested colleagues to the original papers. A comprehensive selection of further information for each star is given in the individual notes. In addition, the catalog contains a candidate list of 138 stars that have similar characteristics but are not definitely known binaries or have not had Ca II H and K emission observed. This version updates and replaces the 1988 catalog of similar information. (Strassmeier et al., 1988).
- ID:
- ivo://CDS.VizieR/V/128
- Title:
- Chromospherically Active Binaries. Third version
- Short Name:
- V/128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Chromospherically Active Binaries (CAB) catalogue have been revised and updated. With 203 new identifications, the number of CAB stars is increased to 409. Catalogue is available in electronic format where each system has various number of lines (sub-orders) with a unique order number. Columns contain data of limited number of selected cross references, comments to explain peculiarities and position of the binarity in case it belongs to a multiple system, classical identifications (RS CVn, BY Dra), brightness and colours, photometric and spectroscopic data, description of emission features (Ca II H&K, H{alpha}, UV, IR), X-Ray luminosity, radio flux, physical quantities and orbital information, where each basic entry are referenced so users can go original sources.
- ID:
- ivo://CDS.VizieR/J/ApJ/835/61
- Title:
- Chromospherically active stars in RAVE. II.
- Short Name:
- J/ApJ/835/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A large sample of over 38000 chromospherically active candidate solar-like stars and cooler dwarfs from the RAVE survey is addressed in this paper. An improved activity identification with respect to the previous study was introduced to build a catalog of field stars in the solar neighborhood with an excess emission flux in the calcium infrared triplet wavelength region. The central result of this work is the calibration of the age-activity relation for main-sequence dwarfs in a range from a few 10Myr up to a few Gyr. It enabled an order of magnitude age estimation of the entire active sample. Almost 15000 stars are shown to be younger than 1Gyr and ~2000 younger than 100Myr. The young age of the most active stars is confirmed by their position off the main sequence in the J-K versus N_UV_-V diagram showing strong ultraviolet excess, mid-infrared excess in the J-K versus W_1_-W_2_ diagram, and very cool temperatures (J-K>0.7). They overlap with the reference pre-main-sequence RAVE stars often displaying X-ray emission. The activity level increasing with the color reveals their different nature from the solar-like stars and probably represents an underlying dynamo-generating magnetic fields in cool stars. Of the RAVE objects from DR5, 50% are found in the TGAS catalog and supplemented with accurate parallaxes and proper motions by Gaia. This makes the database of a large number of young stars in a combination with RAVE's radial velocities directly useful as a tracer of the very recent large-scale star formation history in the solar neighborhood.
- ID:
- ivo://CDS.VizieR/J/AZh/73/194
- Title:
- Circumstellar Disks of Ae/Be Herbig Stars
- Short Name:
- J/AZh/73/194
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The data of the photo-polarimetric activity of Ae/Be Herbig stars and the types of Ha profiles observed in their spectra was carried out using data from the literature. The analysis of the data supports the presence of a relationship between the type of Ha profile and the level of photo-polarimetric activity in young stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/606/L73
- Title:
- CO emission of 5 Herbig Ae stars
- Short Name:
- J/ApJ/606/L73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore the high-resolution ({Lambda}/{Delta}{Lambda}=25000;{Delta}v=12km/s) M-band (4.7-5.1{mu}m) spectra of several disk-dominated Herbig Ae (HAe) systems: AB Aur, MWC 758, MWC 480, HD 163296, and VV Ser.
- ID:
- ivo://CDS.VizieR/J/MNRAS/353/601
- Title:
- 2dF survey of the Small Magellanic Cloud
- Short Name:
- J/MNRAS/353/601
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of new spectral types for hot, luminous stars in the Small Magellanic Cloud. The catalogue contains 4161 objects, giving an order of magnitude increase in the number of SMC stars with published spectroscopic classifications. The targets are primarily B- and A-type stars (2862 and 853 objects respectively), with 1 Wolf-Rayet, 139 O-type, and 306 FG stars, sampling the main sequence to ~mid-B. The selection and classification criteria are described, and objects of particular interest are discussed, including UV-selected targets from the Ultraviolet Imaging Telescope (UIT) experiment, Be and B[e] stars, `anomalous A supergiants', and composite-spectrum systems. We examine the incidence of Balmer-line emission, and the relationship between H-gamma equivalent width and absolute magnitude for BA stars.
