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Start Over Subject late-type stars Publisher CDS
141. FBS 11th list of late-type stars
ID:
ivo://CDS.VizieR/J/other/Ap/44.88
Title:
FBS 11th list of late-type stars
Short Name:
J/other/Ap/44.88
Date:
21 Oct 2021
Publisher:
CDS
Description:
The eleventh list of faint late M and carbon type stars detected on the plates of the First Byurakan Spectral Survey in zone -7{deg}<={delta}<=-3{deg} and covering about 1000 square degrees is presented. From 126 detected stars, 88 are newly discovered objects: they are 6 carbon stars, 8 carbon star candidates, and 74 M-type stars; among the latter 38 (26 PSC + 12 FSC) are unclassified IRAS sources, and one object is an unclassified ROSAT source. Distances to the 6 newly discovered early-type carbon stars are estimated. Equatorial coordinates, red magnitudes, and spectral classes determined from the Palomar E-charts are provided. The lack of optical counterparts on Palomar O and E maps for two detected late M-type stars indicates a large variability in brightnesses of these objects (amplitude not smaller than 7.0 magnitude).
142. FBS 12th list of late-type stars
ID:
ivo://CDS.VizieR/J/other/Ap/44.328
Title:
FBS 12th list of late-type stars
Short Name:
J/other/Ap/44.32
Date:
21 Oct 2021
Publisher:
CDS
Description:
The twelfth list of faint late M and carbon type stars detected on the plates of the First Byurakan Spectral Survey in zone -30{deg}<={delta}<=1{deg} covering about 1070 sq. degrees is presented. From 86 detected stars, 57 are newly discovered objects: they are 3 R-type carbon stars, 2 carbon star candidates and 52 M-type stars. Among the latter 34 (28 PSC + 6 FSC) are unclassified IRAS sources. Equatorial coordinates, spectral classes, color indices, and red magnitudes determined from the Palomar E-charts are presented.
143. FBS 10th list of red stars
ID:
ivo://CDS.VizieR/J/other/Ap/41.356
Title:
FBS 10th list of red stars
Short Name:
J/other/Ap/41.35
Date:
21 Oct 2021
Publisher:
CDS
Description:
A 10th list of late-type M and C stars found on plates of the First Byurakan Spectral Sky Survey in the -11{deg}<{delta}<-7{deg} belt within area of about 1070{deg}^2^ is given. The list contains data on 169 red stars, 117 of which were found for the first time: 8 are new C stars, 3 are C-star candidates, 104 are M stars, 1 is either an M or an S star, and 1 object on the survey plate cannot be classified; of the 117 objects, 47 are unidentified IRAS sources. A statistical analysis of the objects that are and are not identified with IRAS sources shows that the identified stars are, with a high probability, brighter and have relatively more massive envelopes. Two stars were found to have fairly large brightness variability (with an amplitude of at least 6.0mag). Gas-dust shells are assumed to exist around nine of the IRAS sources. The equatorial coordinates, spectral types, and stellar magnitudes, determined on Palomar E maps, are given for the selected objects.
144. [Fe/H], Vel, Orbits of F2-K5 Dwarfs 80pc from Sun
ID:
ivo://CDS.VizieR/V/58
Title:
[Fe/H], Vel, Orbits of F2-K5 Dwarfs 80pc from Sun
Short Name:
V/58
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this catalog, metallicities, distances, components of space velocities and parameters of osculating orbits are calculated for 1065 F2-K5 dwarfs with UBV photometric data, proper motions and radial velocities. The present sample is composed on the base of the Ochsenbein (1980) catalogue and contains the stars of the V (IV-V) luminosity class, within the colour range 0.35<B-V<1.10 (which corresponds to the spectral class range F2-K5). Sandage's (1969) Hyades sequence was used to determine the value delta (U-B) for each star. The authors calibrated the ultraviolet excess in terms of [Fe/H] separately for the four of the temperature index (B-V) where delta(U-B) practically does not depend on the effective temperature. Intervals in (B-V) correspond to the following division on spectral class intervals: F2-F9, G0-G4, and G5-G9, K0-K5. Metallicity is calculated from the formulae: [Fe/H]=-5.3*delta(U-B)+0.02 for stars F2-F9 [Fe/H]=-5.1*delta(U-B)+0.13 for stars G0-G4 [Fe/H]=-5.4*delta(U-B)+0.02 for stars G5-G9 [Fe/H]=-4.7*delta(U-B)-0.04 for stars K0-K5 These relations follow from the assumption that mean metallicity and metallicity dispersion for stars of all spectral classes are the same. Distances to the stars were calculated from spectral parallaxes. Absolute magnitudes (M(V)) were obtained from the Sp,M(V)-relation for dwarfs (Straizys, 1982). The sample includes only stars nearer than 80 pc because reddening is negligible for them. The obtained distances together with radial velocities and proper motions are used to calculate the components of space velocities. The eccentricities, apogalactic and perigalactic distances of the stars were calculated from the osculating orbit approximation according to the galaxy model from the paper by Eggen et al. (1962).
145. F, G and K stars BVRI photometry
ID:
ivo://CDS.VizieR/J/A+AS/131/197
Title:
F, G and K stars BVRI photometry
Short Name:
J/A+AS/131/197
Date:
15 Dec 2021 08:12:40
Publisher:
CDS
Description:
We present accurate BV(RI)c photometry for a sample of F, G and K stars detected in selected areas of the ROSAT all-sky survey (RASS). We have used the photometry, in addition to low-resolution spectroscopy, to estimate spectral classifications, distances and X-ray luminosities. The log(L_X_/L_V_) in the sample lies below -2. Although the sample contains also nearby, inactive stars, it is dominated by active objects. The median X-ray luminosity in our sample is <L_X_>=29.88 and the mean value of the hardness ratios <HR1>=0.13+/-0.35. We compare the derived X-ray luminosity function with similar functions obtained from the serendipitous samples of the Einstein Observatory medium sensitivity survey (EMSS, Cat. <IX/15>) and EXOSAT (Cat. <J/A+AS/115/41>). Our sample is completely consistent with the EMSS sample of solar type stars, indicating that both our sources and the EMSS sources are representative of the high galactic latitude X-ray stellar population. We do not find extremely active stars (log(L_X_)>=32), as are found in the EMSS sample, and we argue that these objects are rare.
146. FGK dwarfs atmospheric parameters
ID:
ivo://CDS.VizieR/J/MNRAS/456/1221
Title:
FGK dwarfs atmospheric parameters
Short Name:
J/MNRAS/456/1221
Date:
21 Oct 2021
Publisher:
CDS
Description:
We performed extensive tests of the accuracy of atmospheric parameter determination for FGK stars based on the spectrum fitting procedure Spectroscopy Made Easy (sme). Our stellar sample consists of 13 objects, including the Sun, in the temperature range 5000-6600K and metallicity range -1.4-/+0.4. The analysed stars have the advantage of having parameters derived by interferometry. For each star, we use spectra obtained with different spectrographs and different signal-to-noise ratios (S/N). For the fitting, we adopted three different sets of constraints and test how the derived parameters depend upon the spectral regions (masks) used in sme. We developed and implemented in sme a new method for estimating uncertainties in the resulting parameters based on fitting residuals, partial derivatives, and data uncertainties. For stars in the 5700-6600K range, the best agreement with the effective temperatures derived by interferometry is achieved when spectrum fitting includes the H{alpha} and H{beta} lines, while for cooler stars the choice of the mask does not affect the results. The derived atmospheric parameters do not strongly depend on spectral resolution and S/N of the observations, while the uncertainties in temperature and surface gravity increase with increasing effective temperature, with minima at 50K in Teff and 0.1dex in logg, for spectra with S/N=150-200. A non-local thermodynamic equilibrium (NLTE) analysis of the TiI/TiII and FeI/FeII ionization equilibria and abundances determined from the atomic CI (NLTE) and molecular CH species supports the parameters we derived with sme by fitting the observed spectra including the hydrogen lines.
147. First brown dwarfs discovered by WISE
ID:
ivo://CDS.VizieR/J/ApJS/197/19
Title:
First brown dwarfs discovered by WISE
Short Name:
J/ApJS/197/19
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present ground-based spectroscopic verification of 6 Y dwarfs (see also Cushing et al., 2011ApJ...743...50C), 89 T dwarfs, 8 L dwarfs, and 1 M dwarf identified by the Wide-field Infrared Survey Explorer (WISE). Eighty of these are cold brown dwarfs with spectral types >=T6, six of which have been announced earlier by Mainzer et al. (2011ApJ...726...30M) and Burgasser et al. (2011ApJ...735..116B). We present color-color and color-type diagrams showing the locus of M, L, T, and Y dwarfs in WISE color space. Near-infrared and, in a few cases, optical spectra are presented for these discoveries. Near-infrared classifications as late as early Y are presented and objects with peculiar spectra are discussed. Using these new discoveries, we are also able to extend the optical T dwarf classification scheme from T8 to T9. After deriving an absolute WISE 4.6um (W2) magnitude versus spectral type relation, we estimate spectrophotometric distances to our discoveries. We also use available astrometric measurements to provide preliminary trigonometric parallaxes to four of our discoveries, which have types of L9 pec (red), T8, T9, and Y0; all of these lie within 10pc of the Sun. The Y0 dwarf, WISE 1541-2250, is the closest at 2.8^+1.3^_-0.6_pc; if this 2.8pc value persists after continued monitoring, WISE 1541-2250 will become the seventh closest stellar system to the Sun. Another 10 objects, with types between T6 and >Y0, have spectrophotometric distance estimates also placing them within 10pc. The closest of these, the T6 dwarf WISE 1506+7027, is believed to fall at a distance of ~4.9pc. WISE multi-epoch positions supplemented with positional info primarily from the Spitzer/Infrared Array Camera allow us to calculate proper motions and tangential velocities for roughly one-half of the new discoveries.
148. First Byurakan Survey Late Type Stars catalog
ID:
ivo://CDS.VizieR/III/246
Title:
First Byurakan Survey Late Type Stars catalog
Short Name:
III/246
Date:
21 Oct 2021
Publisher:
CDS
Description:
The First Byurakan Survey (FBS), also known as the Markarian survey, covers about 17000 sq. deg. It has been used by Markarian and his collaborators to search for UV excess galaxies (see Cat. VII/172), by Abrahamyan and his collaborators to search for late type stars and UV excess or emission line point sources (stars and starlike objects). The identification, classification, and investigation of late type stars and blue stellar objects constitutes the second part of the First Byurakan Survey and is a natural continuation of it. For this second program, at the present time, a catalogue of 1103 blue objects has been built (see Cat. II/223). In a series of 14 papers, referenced in the "References" section below, have been published lists of 1000 late M type and carbon stars, selected on the FBS plates. We have revised and updated this 14 lists with the new data from recently published optical and infrared catalogs to give access to all available data. As a result, the catalog of the First Byurakan Survey (FBS) Late Type Stars, was compiled. In this catalogue are presented high accurate coordinates, proper motions, spectral, photometric and infrared dates about of 995 FBS late M type and carbon stars. Are given cross-identifications of FBS late type stars with their counterparts from the most popular catalogs (2MASS, USNO-B1, NOMAD, UCAC2, GCVS4.2, NSVS, ASAS, IRAS PS and IRAS FS). On the base of 2MASS (J-K) color indices were determined a luminosity classes for 988 of them. For the 55 stars were determined a spectral classes, and for the another 129 were determined a spectral subclasses on the base of DFBS (http://byurakan.phys.uniroma1.it/) These data were not presented in original lists.
149. First Byurakan Survey of Late-Type Stars - v2
ID:
ivo://CDS.VizieR/J/MNRAS/489/2030
Title:
First Byurakan Survey of Late-Type Stars - v2
Short Name:
J/MNRAS/489/2030
Date:
21 Oct 2021
Publisher:
CDS
Description:
A total of 18 lists of the First Byurakan Survey of Late-Type Stars (FBS LTS) were published between 1990 and 2016. The stars were found on FBS low-dispersion spectroscopic plates. A systematic search and selection were carried out on a surface of ~16000deg^2^ on almost the whole area of the FBS. As a result, the "Revised and Updated Catalogue of the First Byurakan Survey of Late-Type Stars" was generated (FBS LTS v1; see Cat. III/266 -- 1045 objects). We present the second version of the catalogue of FBS LTS with new data (FBS LTS v2), comprising 1471 objects. It is a homogeneous and complete data base for high-Galactic-latitude, late-type stars, including M and C types. Since 2007, all FBS low-resolution spectral plates have been digitized. All digitized FBS (DFBS) spectral plates have been analysed with FITSVIEW and SAO IMAGE DS9, and numerous relatively faint LTSs have been discovered. We have performed cross-correlations with DFBS, USNO-B1.0, 2MASS, AllWISE, IRAS PSC/FSC, AKARI, ROSAT BSC/FSC, GCVS, SDSS and added updated SIMBAD data. For numerous new detected objects, we present accurate DSS2 positions, approximate spectral subtypes refined from the DFBS low-dispersion spectra, luminosity classes estimated from 2MASS colours, and available proper motions for 1471 FBS LTSs. The Revised and Updated Catalogue v2 lists a large number of completely new objects, which promises to extend very significantly the census of M giants, faint N-type asymptotic giant branch carbon stars, CH-type carbon giants at high Galactic latitudes, and M dwarfs in the Solar vicinity up to 16.0-17.0mag in the visual. Some important data from Gaia DR2 and supplementary spectra from the Byurakan Astrophysical Observatory 2.6m and LAMOST telescopes are presented.
150. F-K evolved stars Ca II activity and rotation
ID:
ivo://CDS.VizieR/J/A+A/361/1011
Title:
F-K evolved stars Ca II activity and rotation
Short Name:
J/A+A/361/1011
Date:
21 Oct 2021
Publisher:
CDS
Description:
CaII H and K high resolution observations for 60 evolved stars in the field and in 5 clusters are presented. From these spectra chromospheric fluxes are derived, and a homogeneous sample of more than 100 giants is built adding data from the literature. In addition, for most stars, rotational velocities were derived from CORAVEL observations.

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