Third Catalogue Of Nearby Stars Research Articles

A SPECTROSCOPIC CATALOG OF THE BRIGHTEST (J< 9) M DWARFS IN THE NORTHERN SKY,

We present a spectroscopic catalog of the 1,564 brightest (J<9) M dwarf candidates in the northern sky, as selected from the SUPERBLINK proper motion catalog. Observations confirm 1,408 of the candidates to be late-K and M dwarfs with spectral subtypes K7-M6. From the low \mu>40 mas/yr proper motion limit and high level of completeness of the SUPERBLINK catalog in that magnitude range, we estimate that our spectroscopic census most likely includes >90% of all existing, northern-sky M dwarfs with apparent magnitude J<9. Only 682 stars in our sample are listed in the Third Catalog of Nearby Stars (CNS3); most others are relative unknowns and have spectroscopic data presented here for the first time. Spectral subtypes are assigned based on spectral index measurements of CaH and TiO molecular bands. A comparison of spectra from the same stars obtained at different observatories however reveals that spectral band index measurements are dependent on spectral resolution, spectrophotometric calibration, and other instrumental factors. After systematic corrections and a recalibration of the subtype-index relationships, we find that we can consistently and reliably classify all our stars to a half-subtype precision. The use of corrected spectral indices further requires us to recalibrate the \zeta parameter, from which we estimate metallicities +/-0.5dex accuracy in dwarfs of subtypes M2 and earlier, and +/-0.2dex accuracy for later (M3-M5) subtypes. Existing geometric parallax measurements are extracted from the literature for 624 stars, and are used to determine spectroscopic and photometric distances for all the other stars. Our catalog will be most useful to guide the selection of the best M dwarf targets for exoplanet searches, in particular those using high-precision radial velocity measurements.

Disk populations from HIPPARCOS kinematic data

The full space motions – including radial velocities – of a stellar sample drawn from HIPPARCOS catalogue are used to discriminate differentiated statistical behaviours that are associated with stellar populations in the solar neighbourhood. A sampling parameter is used to build a hierarchical set of nested samples, where a discontinuous pattern, based in a partition introduced by two normal distributions, scans the subsamples. Two quantities inform whether any subsample fits properly into the discontinuous model. A χ 2 test measures the Gaussianity of both components, and the entropy of the mixture probability gives account of how informative the resulting segregation is. The less informative partition is the one with maximum population entropy, which provides most representative kinematic parameters. Each new population merged to the cumulative subsample produces a discontinuity in the plot entropy versus sampling parameter, that allows to determine the number of populations contained in the whole sample. The resulting method has been named MEMPHIS, Maximum Entropy of the Mixture Probability from HIerarchical Segregation. In addition to both main kinematic components, thin and thick disk, with respective velocity dispersions (28 ± 1, 16 ± 2, 13 ± 1) and (65 ± 2, 39 ± 9, 41 ± 2) km s −1 , two discrete non-Gaussian subcomponents are detected within the thin disk. These populations are identified with early-type and young disk stars. Moreover, a continuous old disk population is mixed with the foregoing subcomponents composing all together the thin disk. Older thin disk stars have a velocity dispersion overlapping a wing of the thick disk. Although they could appear like an intermediate continuous population, nested subsamples distributions allow us to conclude that they definitively belong to the thin disk, and that a clear discontinuity detaches thick from thin disk. Almost the same qualitative results, but with less accuracy, are obtained whether MEMPHIS is applied to subsamples from the Third Catalogue of Nearby Stars (CNS3). A dynamic model according to Chandrasekhar’s approximation, under particular symmetry hypotheses, allows to interpret the results. The non-vanishing vertex deviation – lower for older stars – of all Galactic components is suggesting that, at least, point-axial symmetry is required in order to explain the local kinematic behaviour. According to this model, the oldest thick disk population, with no net radial movement, can be extrapolated, having heliocentric velocities of −76 ± 2k m s −1 in rotation, and −18 ± 1k m s −1 in the radial direction. Early-type stars show a worthy local singularity, nearly with no net radial motion, similarly to the oldest thick disk stars. Older populations – half of the thin disk and the whole thick disk – share a common differential galactic movement, suggesting a common dynamical origin for the rupture of the axial symmetry. The relationship between the maximum stellar velocity of a sample and its average age τ is discussed, finding an approximate relation |V|max ∝ τ. Local stellar populations can be described from a Titius-Bode-like law for the radial velocity dispersion, σ1 = 6. 6( 4 ) x , so that for natural values x = 2, 3, 5, 8 it determines average energy levels of discrete populations, while for continuous intervals x ≤ 5a ndx ≥ 7 it describes the velocityage evolution of thin and thick disk components, according to x ∼ 1. 5l nτ.

New Distant Companions to Known Nearby Stars. I. GJ 4047B, GJ 718B, GJ 747.2C, GJ 4100B, and GJ 4153B

In an ongoing survey for high proper motion stars at low Galactic latitudes (-25° < b < 25°) in the Digitized Sky Survey, we have identified five previously uncataloged common proper motion companions to stars listed in the Preliminary Version of the Third Catalogue of Nearby Stars (GJ stars). For each system, the relative proper motion between the components is less than 5% of the common proper motion of the pair. Spectra of the pairs have been obtained at the Lick 3 m Shane Telescope, confirming that the systems are indeed wide-separation binaries. The systems are classified as follows: GJ 4047AB = K5 V + M5 V, GJ 718AB = K5 V + M4.5 V, GJ 747.2ABC = (K7 V + K7 V) + M4 Ve, GJ 4100AB = M1 V + M4.5 Ve, and GJ 4153AB = M0.5 V + M3.5 V. The total area surveyed contains 346 Gliese stars, which suggests that ≈1.5% of the stars listed in the Preliminary Version of the Third Catalogue of Nearby Stars have unrecognized proper motion companions. We predict that ≈15–50 more new distant companions to GJ stars will be discovered in the Digitized Sky Survey.

The ROSAT all-sky survey catalogue of the nearby stars

We present X-ray data for all entries of the Third Catalogue of Nearby Stars (Gliese & Jahrei 1991) that have been detected as X-ray sources in the ROSAT all-sky survey. The catalogue contains 1252 entries yield- ing an average detection rate of 32.9 percent. In addi- tion to count rates, source detection parameters, hardness ratios, and X-ray fluxes we also list X-ray luminosities derived from Hipparcos parallaxes.

The Luminosity Function of the Main Sequence Stars in the Solar Neighborhood

The Third Catalogue of Nearby Stars (CNS3) was analyzed. A study of the stellar luminosity function in the solar neighborhood with CNS3 was described. The luminosity function for main sequence stars derived from CNS3 was compared with that from CNS2 and that based on the method of photometric parallaxes. The results from CNS3 for stars with Mv &lt;15.5 were well defined. Luminosity functions for the giants and A, F, G, K and M type main sequence stars are also given, based on CNS3.

PROBING THE LHS CATALOG. I. NEW NEARBY STARS AND THE COOLEST SUBDWARF

ABSTRACT We present moderate resolution spectroscopy of 112 cool dwarf stars to supplement the observations we have already presented in the Palomar/MSU Nearby-Star Spectroscopic Survey. The sample consists of 72 suspected nearby stars added to the The Preliminary Third Catalog of Nearby Stars since 1991 as well as 40 faint red stars selected from the LHS catalog. LHS 1826 is more metal-poor and cooler than the coolest previously known extreme subdwarf, LHS 1742a. LHS 2195 is a very late M dwarf of type M 8 V, probably at a distance of ten parsecs. LHS 1937 is an M 7 V star at ~ 20 parsecs. Three other previously unobserved LHS stars have estimated distances that place them within 25 parsecs.

The Scatter of Metallicities of Stars in the Solar Neighbourhood

It is well known that the velocity dispersions of the stars in the solar neighbourhood increase with their ages (Wielen 1977). In Fig.1 we show |W| weighted velocity dispersions (cf. Wielen 1977) of the stars in the Third Catalog of Nearby Stars (Gliese and Jahreiß 1994). Open symbols indicate main sequence stars and crosses indicate McCormick stars, a kinematically unbiased subset of the CNS3, respectively, whereas the filled symbols are the Edvardsson et al. (1993) data. Stars older than 14 Gyr are not shown because they are probably thick disk stars (Freeman 1991). We have assumed a maximum age of the old thin disk stars of 12 Gyr as suggested by the Edvardsson et al. data. As can be seen from Fig.1 both data sets fit ideally together. The solid line indicates a σ ∝ τ1/2 law.

The Palomar/MSU Nearby-Star Spectroscopic Survey. I. The Northern M Dwarfs -Bandstrengths and Kinematics

view Abstract Citations (564) References (69) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Palomar/MSU Nearby-Star Spectroscopic Survey. I. The Northern M Dwarfs -Bandstrengths and Kinematics Reid, I. Neill ; Hawley, Suzanne L. ; Gizis, John E. Abstract The Third Catalogue of Nearby Stars (Gliese & Jahreiss Preliminary Version of the third Catalogue of Nearby Stars, 1991) includes over 1850 stars which lie north of δ 30° and are either identified as spectral type M, or are unclassified but with an absolute visual magnitude estimate MV>+8.O. Although there is no uniformity in selection criteria, and many of the stars lack basic data (radial velocities, spectral types, accurate photometry), the observational properties of these stars underlie most estimates of the fundamental characteristics of the Galactic Disk. We have obtained optical spectroscopy of 1746 of the 1876 stars-the remaining 130 are binary companions of brighter stars and inaccessible to our observations. These spectra allow us, first, to exclude 61 stars as either degenerates or as misclassified earlier-type (B - K) stars lying beyond the 25 pc limit; to establish radial velocities accurate to ±10 km s-1 for all stars confirmed as late-type dwarfs; to determine spectral types and absolute magnitudes from the TiO bandstrength, allowing more accurate distance estimates for stars with inaccurate (or no) trigonometric parallax measurements; and to identify stars with Ha emission (chromospherically active stars) and with strong CaH absorption (perhaps including some metal-poor disk subdwarfs). We have determined the nearby-star luminosity function from complete samples derived by applying both the distance limits defined by Wielen (1974) and by using limits derived from our own analysis. In both cases, we find good agreement with Wielen's results to MV ∼+11, but lower densities at the maximum (MV∼+12). The latter analysis results in a luminosity function, ΦCNS, which closely matches photometric parallax analyses for MV<+11 and MV>+14 -- we do not recover the apparent excess of low-luminosity stars inferred from analysis of the 5 pc sample. However, ΦCNS does lie below Φphot at the peak (MV∼12), and we suggest that this offset is caused by the inclusion of unrecognized binaries in the photometric surveys. We have also reanalyzed the local stellar kinematics using the complete sample and find that the velocity distributions show significant departures from single Gaussian velocity dispersions. Publication: The Astronomical Journal Pub Date: October 1995 DOI: 10.1086/117655 Bibcode: 1995AJ....110.1838R Keywords: STARS: FUNDAMENTAL PARAMETERS; SURVEYS; STARS: PECULIAR; STARS: LUMINOSITY FUNCTION full text sources ADS | data products SIMBAD (1848) CDS (2) Related Materials (2) Catalog: 1997yCat.3198....0R Part 2: 1996AJ....112.2799H

Flare Activity Among Nearby Stars

I selected the common objects from our Data Base on 234 UV Cet Flare Stars and Related Objects and the Third Catalogue of Nearby Stars by Gliese &amp; Jahreiss (CNS-3). It is found that manifestation of flare activity (FA) (flares in any spectral region or photometric variability caused by spots) is observed on 143 flare stars (FS) out of the 3803 CNS-3 stars within 25 pc of the Sun with absolute magnitudes Mv from 5.2 (Sp G2 V) to 18.8 (Sp dM5e − dM6e).Magnitudes and spectra of flare stars: For each MV-interval, Table 1 gives the “mean” spectral class (Sp), the number of FS (Nf) and the portion of FS among other red dwarf stars from CNS-3 (Nf/N). Absolutely fainter stars include a higher portion of known FS. However, observational selection effects can cause this dependence, because the probability is higher to register flares over the background radiation of a faint star. The observed portion of FS among all red dwarfs from CNS-3, which are fainter than Mv=5, is about 5%.

The Third Catalogue of Nearby Stars — Results and Conclusions

The nearby stars constitute the statistically most complete and therefore most representative sample of stars in our Galaxy. Only this sample allows a direct investigation of luminosity function and kinematics of low-mass stars.A study of the Third Catalogue of Nearby Stars reveals a considerable increase — not only in quantity but also in quality — in our knowledge of the immediate solar neighbourhood, and reflects very nicely the progress achieved during the last decades — especially in astrometry and photometry. Expectations for the near future (HIPPARCOS) and desiderata for further astrometric and photometric work will be discussed.

The third catalogue of nearby stars with special emphasis on wide binaries

The third catalogue of nearby stars with special emphasis on wide binaries

Esiderata for nearby - star quantities observable with small telescope

At the General Assembly of the IAU at New Delhi van Altena reported on the new General Catalogue of Trigonometric Stellar Parallaxes (GCTSP) which was completed recently at the Yale Observatory. Time seems to be ripe now for the compilation of a Third Catalogue of Nearby Stars which will include all objects known to be nearer than 25 parsecs. This catalogue will contain positions, proper motions, radial velocities, spectral types, broad-band photometry, and parallaxes - quantities won by observations.

Data for the compilation of the “Third catalogue of nearby stars”

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