- ID:
- ivo://CDS.VizieR/J/A+A/382/118
- Title:
- Spectroscopic sub-systems in multiple stars
- Short Name:
- J/A+A/382/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A large sample of visual multiples of spectral types F5-M has been surveyed for the presence of spectroscopic sub-systems. In table 1 we provide basic identifiers for the components or their combinations, average radial velocities, parameters of correlation dips and analysis of the velocity variability and physical relation. Notes contain comments and additional identifiers. Individual radial velocities yet unpublished are listed in table 2. Table 6 is extracted from the Multiple Star Catalog (Cat. <J/A+AS/124/75>) for the analysis of the statistics of spectroscopic+visual multiple stellar systems.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/112/1489
- Title:
- Spectroscopic survey for binaries in NGC 5053
- Short Name:
- J/AJ/112/1489
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried our a radial velocity survey for spectroscopic binaries in the low-density globular cluster NGC 5053. Our sample contains a total of 77 cluster member giant and subgiant stars with visual magnitudes of 14.5-18.6. Of These 77 stars, 66 stars have on average of 3-4 measurements with a total of 236 velocities. A typical velocity error per measurement is 13km/s. The stars in our sample are spatially distributed from the cluster center out to 10arcmin in radius (4.5 core radii). Among theses 66 stars with multiple velocity measurements, we discovered 6 spectroscopic binary candidates.
- ID:
- ivo://CDS.VizieR/J/A+A/420/183
- Title:
- Spectroscopic survey in solar neighborhood
- Short Name:
- J/A+A/420/183
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a high-resolution spectroscopic survey of all the stars more luminous than M_V_=6.5mag within 14.5pc from the Sun. The Hipparcos catalog's completeness limits guarantee that our survey is comprehensive and free from some of the selection effects in other samples of nearby stars. The resulting spectroscopic database, which we have made publicly available, includes spectra for 118 stars obtained with a resolving power of R~50000, continuous spectral coverage between ~362-921nm, and typical signal-to-noise ratios in the range 150-600. We derive stellar parameters and perform a preliminary abundance and kinematic analysis of the F-G-K stars in the sample. The inferred metallicity ([Fe/H]) distribution is centered at about -0.1dex, and shows a standard deviation of 0.2dex.
- ID:
- ivo://CDS.VizieR/J/ApJ/647/303
- Title:
- Spectroscopic survey of hypervelocity stars
- Short Name:
- J/ApJ/647/303
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We discuss our targeted search for hypervelocity stars (HVSs), stars traveling with velocities so extreme that dynamical ejection from a massive black hole is their only suggested origin. Our survey, now half-complete, has successfully identified a total of four probable HVSs plus a number of other unusual objects. Here we report the two most recently discovered HVSs: SDSS J110557.45+093439.5 and possibly SDSS J113312.12+010824, traveling with Galactic rest-frame velocities at least +508+/-12 and 418+/-10km/s, respectively.
- ID:
- ivo://CDS.VizieR/J/AJ/130/1871
- Title:
- Spectroscopic survey of M dwarfs
- Short Name:
- J/AJ/130/1871
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have constructed a sample of M dwarfs out to a distance of ~100pc. This sample of 605 stars (574 M dwarfs and 31 K dwarfs) have been spectroscopically observed, yielding spectral types, radial velocities, H{alpha} equivalent widths, and molecular band indices. Photometric observations have been compiled, with photographic plates providing RI magnitudes and JHKs magnitudes from Two Micron All Sky Survey (Cat. <II/246>) observations. Proper motions were determined by a match to USNO-B (Cat. <I/284>), and distances were computed employing a spectroscopic parallax, allowing the computation of UVW space motions.
- ID:
- ivo://CDS.VizieR/J/A+A/504/829
- Title:
- Spectroscopic survey of youngest field stars
- Short Name:
- J/A+A/504/829
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results of an ambitious ground-based observation programme conducted on 1-4m class telescopes. Our sample consists of 1097 active and presumably young stars, all of them being optical (Tycho Catalogue) counterparts of ROSAT All- Sky Survey X-ray sources in the northern hemisphere. In this paper, we concentrate on the optically brightest (VT<=9.5m) candidates (704 objects).We acquired high-resolution optical spectroscopy in the H{alpha} and/or lithium spectral regions for 426 of such stars without relevant data in the literature. We describe the star sample and the observations and we start to discuss the physical properties of the investigated stars.
- ID:
- ivo://CDS.VizieR/J/A+A/612/A96
- Title:
- Spectroscopic survey of youngest field stars II.
- Short Name:
- J/A+A/612/A96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Star formation in the solar neighborhood is mainly traced by young stars in open clusters, associations, and in the field, which can be identified, for example, by their X-ray emission. The determination of stellar parameters for the optical counterparts of X-ray sources is crucial for a full characterization of these stars. This work extends the spectroscopic study of the RasTyc sample, obtained by the cross-correlation of the TYCHO and ROSAT All-Sky Survey catalogs, to stars fainter than V=9.5mag and aims to identify sparse populations of young stars in the solar neighborhood. We acquired 625 high-resolution spectra for 443 presumably young stars with four different instruments in the northern hemisphere. The radial and rotational velocity (vsini) of our targets were measured by means of the cross-correlation technique, which is also helpful to discover single-lined (SB1), double-lined spectroscopic binaries (SB2), and multiple systems. We used the code ROTFIT to perform an MK spectral classification and to determine the atmospheric parameters (Teff, logg, [Fe/H]) and and vsini of the single stars and SB1 systems. For these objects, we used the spectral subtraction of slowly rotating templates to measure the equivalent widths of the H{alpha} and LiI-6708A lines, which enabled us to derive their chromospheric activity level and lithium abundance. We made use of Gaia DR1 parallaxes and proper motions to locate the targets in the HR diagram and to compute the space velocity components of the youngest objects. We find a remarkable percentage (at least 35%) of binaries and multiple systems. On the basis of the lithium abundance, the sample of single stars and SB1 systems appears to be mostly (about 60%) composed of stars younger than the members of the UMa cluster. The remaining sources are in the age range between the UMa and Hyades clusters (about 20%) or older (20%). In total, we identify 42 very young (PMS-like) stars, which lie above or very close to the Pleiades upper envelope of the lithium abundance. A significant percentage (about 12%) of evolved stars (giants and subgiants) is also present in our sample. Some of these stars are also lithium rich (A(Li)>1.4).
- ID:
- ivo://CDS.VizieR/J/AJ/155/256
- Title:
- Spectroscopic validation of RAVE metal-poor stars
- Short Name:
- J/AJ/155/256
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a medium-resolution (R~2000) spectroscopic follow-up campaign of 1694 bright (V<13.5), very metal-poor star candidates from the RAdial Velocity Experiment (RAVE). Initial selection of the low-metallicity targets was based on the stellar parameters published in RAVE Data Releases 4 (Cat. III/272) and 5 (Cat. III/279). Follow up was accomplished with the Gemini-N and Gemini-S, the ESO/NTT, the KPNO/Mayall, and the SOAR telescopes. The wavelength coverage for most of the observed spectra allows for the determination of carbon and {alpha}-element abundances, which are crucial for considering the nature and frequency of the carbon-enhanced metal-poor (CEMP) stars in this sample. We find that 88% of the observed stars have [Fe/H]=< -1.0, 61% have [Fe/H]=< -2.0, and 3% have [Fe/H]=< -3.0 (with four stars at [Fe/H]=< -3.5). There are 306 CEMP star candidates in this sample, and we identify 169 CEMP Group I, 131 CEMP Group II, and 6 CEMP Group III stars from the A(C) versus [Fe/H] diagram. Inspection of the [{alpha}/C] abundance ratios reveals that five of the CEMP Group II stars can be classified as "mono-enriched second-generation" stars. Gaia DR1 matches were found for 734 stars, and we show that transverse velocities can be used as a confirmatory selection criteria for low-metallicity candidates. Selected stars from our validated list are being followed-up with high-resolution spectroscopy to reveal their full chemical-abundance patterns for further studies.
- ID:
- ivo://CDS.VizieR/J/AJ/150/108
- Title:
- Spectroscopy and HST imaging in ONC
- Short Name:
- J/AJ/150/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent Hubble Space Telescope images have allowed the determination with unprecedented accuracy of motions and changes of shocks within the inner Orion Nebula. These originate from collimated outflows from very young stars, some within the ionized portion of the nebula and others within the host molecular cloud. We have doubled the number of Herbig-Haro objects known within the inner Orion Nebula. We find that the best-known Herbig-Haro shocks originate from relatively few stars, with the optically visible X-ray source COUP 666 driving many of them. While some isolated shocks are driven by single collimated outflows, many groups of shocks are the result of a single stellar source having jets oriented in multiple directions at similar times. This explains the feature that shocks aligned in opposite directions in the plane of the sky are usually blueshifted because the redshifted outflows pass into the optically thick photon-dominated region behind the nebula. There are two regions from which optical outflows originate for which there are no candidate sources in the SIMBAD database.
- ID:
- ivo://CDS.VizieR/J/AJ/150/168
- Title:
- Spectroscopy and photometry for HAT-P-50--HAT-P-53
- Short Name:
- J/AJ/150/168
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery and characterization of four transiting exoplanets by the HATNet survey. The planet HAT-P-50b has a mass of 1.35M_J_ and radius of 1.29R_J_, and orbits a bright (V=11.8mag) M=1.27M_{sun}_, R=1.70R_{sun}_ star every P=3.1220days. The planet HAT-P-51b has a mass of 0.31M_J_ and radius of 1.29R_J_, and orbits a V=13.4mag, M=0.98M_{sun}_, R=1.04R_{sun}_ star with a period of P=4.2180days. The planet HAT-P-52b has a mass of 0.82M_J_ and radius of 1.01R_J_, and orbits a V=14.1mag, M=0.89M_{sun}_, R=0.89R_{sun}_ star with a period of P=2.7536days. The planet HAT-P-53b has a mass of 1.48M_J_ and radius of 1.32R_J_, and orbits a V=13.7mag, M=1.09M_{sun}_, R=1.21R_{sun}_ star with a period of P=1.9616days. All four planets are consistent with having circular orbits and have masses and radii measured to better than 10% precision. The low stellar jitter and favorable R_p_/R_{star}_ ratio for HAT-P-51 make it a promising target for measuring the Rossiter-McLaughlin effect for a Saturn-mass planet.