Stars Of Large Proper Motion Research Articles

Trigonometric parallaxes of 71 large proper motion stars

Trigonometric parallaxes of 71 large proper motion stars

On the Mass‐Ratio Distribution of Spectroscopic Binaries

In this paper we derive the mass-ratio and secondary-mass distributions of a large, well-defined, complete sample of 129 spectroscopic binaries with periods between 1 and 2500 days. The binaries, whose orbits were published recently, were detected by a systematic radial-velocity survey of a sample of more than 1400 large proper motion stars. Three features stand out in the mass-ratio distribution: a rise as the mass ratio goes down to q ~ 0.2, a sharp drop below q ~ 0.2, and a smaller peak at q ~ 0.8. Another way to characterize the results is to state that the distribution includes two populations, one with a high asymmetric peak at q ~ 0.2 and another with a smaller peak at q ~ 0.8, while the minimum between the two populations is centered at q ~ 0.55. The size of the binary sample allows us to divide it into two subsamples and look for differences in the mass-ratio distributions of the two subsamples. We performed two different divisions: one into Galactic halo versus disk populations, and the other into high- and low-mass primary stars (above and below 0.67 M☉). The former division yields differences with moderate statistical significance of 88%, while the latter is more significant at a level of 97%. Our analysis suggests that the rise toward low mass ratios does not appear in the mass-ratio distribution of the halo binaries. The other separation shows a broad peak at mass ratio of q ~ 0.8-1 for the subsample of binaries with low-mass primaries but no corresponding peak in the subsample with high-mass primaries. We discuss our findings and their application to theories of binary formation.

Spectroscopic Follow-Up of Large Proper-Motion Stars in ESO Areas 207, 439, and 440

Spectroscopic Follow-Up of Large Proper-Motion Stars in ESO Areas 207, 439, and 440

The variable stars in the field of the globular cluster NGC 6544

view Abstract Citations (4) References (5) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Variable Stars in the Field of the Globular Cluster NGC 6544 Hazen, Martha L. Abstract A search for variable stars in the neighborhood of the galactic globular cluster NGC 6544 has located two variables within the tidal radius of the cluster and two outside. A star of large proper motion was also detected. One of the variables within the tidal radius is possibly an eclipsing binary; the other is a RR Lyrae type ab star that may be a cluster member. The two field variables are RR Lyrae type ab stars. Publication: The Astronomical Journal Pub Date: September 1993 DOI: 10.1086/116703 Bibcode: 1993AJ....106.1055H Keywords: Eclipsing Binary Stars; Globular Clusters; Variable Stars; Astronomical Photography; Image Analysis; Stellar Magnitude; Stellar Spectrophotometry; Astronomy; GLOBULAR CLUSTERS: INDIVIDUAL: NGC 6544; STARS: VARIABLES: RR LYRAE full text sources ADS | data products SIMBAD (26)

Luminosities, abundances, and motions of stars brighter than visual magnitude 15.1 and annual proper motions larger than one-half arcsecond

view Abstract Citations (28) References (35) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Luminosities, Abundances, and Motions of Stars Brighter than Visual Magnitude 15.1 and Annual Proper Motions Larger than One-Half Arcsecond Eggen, Olin J. Abstract The stars with annual proper motion larger than 0.5 arcsec (PM I, II, III) and for which both photometry and radial-velocity determinations are available confirm the complete absence of objects with planar, galactic orbital eccentricities greater than 0.5 and [Fe/H] more than - 0.6 dex. Adopting an eccentricity of at least 0.5 as the definition of a halo star leads to a minimum density in the solar neighborhood of 41 x l0-5 pc-3 for Mv brighter than + 13 mag, with an additional 39 x l0-5 pc-3 from two white dwarfs of Mv = + 14 and + 15 mag. The luminosity function for the halo stars shows a sharp malconformation between Mv = + 5 and + 7 mag and a slope, for lower luminosities, of γ =0.047 (φ = 10γ( Mv-6)). The luminosity function of the disk (nonhalo) stars of large proper motion is very similar to the GLF (McCuskey 1966) but its slope, like that of the GLF, is considerably less than that found for the nearest stars. The relationship between the photometric abundances P[Fe/H] and the W (perpendicular) component of the space motion can be represented by a uniformly increasing upper limit ∣W + 6∣ = 70 - 50P[Fe/H] km s-1, which excludes only six stars of the sample. Space-motion vectors of all stars in PM I, II, and III for which the planar orbital eccentricity exceeds 0.5 from the photometric luminosities and proper motions alone, together with the percentage contribution from the unknown radial velocity, are tabulated, as are those of the disk (nonhalo) objects, and it is from these lists that probable and possible halo stars can be selected for confirming radial-velocity determinations. The luminosities discussed here are based on main sequences for the halo and disk populations that are confirmed by stellar models, and on calibrations of photometric indices, applied to the interme- diate band, (R,I), and/or Hβ photometry obtained for 400 stars in PM I, II, and III. The photometry is also used for abundance determinations, based on previously published calibrations. Publication: The Astronomical Journal Pub Date: February 1987 DOI: 10.1086/114324 Bibcode: 1987AJ.....93..393E Keywords: Abundance; Astronomical Catalogs; Radial Velocity; Stellar Luminosity; Stellar Motions; Visible Spectrum; Annual Variations; Solar Neighborhood; Stellar Envelopes; Stellar Orbits; Stellar Spectrophotometry; Astronomy; STARS: PROPER-MOTION; STARS: ABUNDANCES; STARS: LUMINOSITIES full text sources ADS | data products SIMBAD (408)

THREE COMMON PROPER MOTION PAIRS.

ABSTRACT Three large proper-motion stars have been found to be doubles, components having common proper motion.

Luminosity and motion of large proper motion stars. II - Stars with annual proper motion larger than 0.7 arc seconds

Luminosity and motion of large proper motion stars. II - Stars with annual proper motion larger than 0.7 arc seconds

New results from a survey of faint proper-motion stars - A probable deficiency of very low luminosity degenerates

view Abstract Citations (112) References (72) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS New results from a survey of faint proper-motion stars: a probable deficiency of very low luminosity degenerates. Liebert, J. ; Dahn, C. C. ; Gresham, M. ; Strittmatter, P. A. Abstract Spectroscopic classifications and broad-band colors are presented largely for faint Luyten proper-motion stars with > 1" yr -`. Our primary goal was to find nearby white dwarfs of very low luminosity (VLL)-i.e., with Mbol > + which recent theoretical calculations predict substantial numbers. The only possible case, LP 131-66, is discussed in detail elsewhere. Furthermore, no additional artificially red "blanketed" stars like LP 701-29 were found. Questions concerning the completeness of Luyten's catalogs are discussed, specifically for very faint stars of large proper motion; we believe that the catalogs are 50% complete for stars with m < 18.0 in finished Luyten Palomar fields. We also consider the likelihood of finding VLL objects as brighter, very nearby (<5 pc) stars, and as common proper-motion companions to nearby K-M dwarfs. It is concluded that there is probably a large deficiency of VLL degenerates relative to the predicted numbers from (1) the Shaviv-Kovetz 0.6 M0 cooling curve, (2) normalized to Green's empirical density of hot stars, and (3) with the assumption of a constant white dwarf birthrate. We consider it unlikely that the deficiency in VLL stars will be completely explained by drastic errors in the cooling theory. In particular, we consider the possibilities that Debye cooling might begin at higher luminosities than predicted or that Stevenson s insolubility effects could produce additional gravitational enefgy in a crystallizing core. Yet the empirical deficiency becomes even worse when one assumes a conventional" disk star-formation picture-a disk age of 15 x 10 years with star formation much greater in the past. Alternatively, if most disk star formation occurred 1010 years ago, a curtailment of white dwarfs in the VLL interval can be explained. These results thus support the view that the stellar disk is effectively much younger than the currently accepted age of the halo. In addition to white dwarfs, the search plan uncovered several new M dwarfs of very low luminosity and a substantial number of very cool subdwarfs. Contrary to previous experience, not one M dwarf with probable Mv > +15 showed strong line emission at Ha; most were observed at least twice, though at moderate (6-12 A) resolution. Individual discussions of white dwarfs include (1) the classification of the fourth Praesepe cluster member LB 1847 (EG 60) as DA, (2) the abundances of GD 401 (Gr 451), (3) two DB stars BPM 70524 and LB 433, and (4) some nonvariable DA stars. Finally, we report that GD 439 has a subdwarf G spectrum with a very strong CH band; the proper motion constrains Mv to be +4, making this another carbon subdwarf candidate. Subject headings: stars: late-type - stars: proper-motion - stars: stellar statistics - stars: white dwarfs Publication: The Astrophysical Journal Pub Date: October 1979 DOI: 10.1086/157384 Bibcode: 1979ApJ...233..226L Keywords: Astronomical Spectroscopy; Late Stars; Stellar Luminosity; Stellar Motions; White Dwarf Stars; Astronomical Catalogs; Searching; Astrophysics; Low-Luminosity Stars:Stellar Statistics; Nearby Stars:White Dwarfs; Proper-Motion Stars:Surveys full text sources ADS | data products SIMBAD (84)

Luminosity and motion of large proper-motion stars. I - Stars with annual proper motion larger than 1 arcsec

view Abstract Citations (29) References (37) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Luminosity and motion of large proper-motion stars. I. Stars with annual proper motion larger than 1". Eggen, O. J. Abstract The luminosities and motions of stars brighter than visual magnitude 15 and annual proper motion greater than one arcsec given in a catalog published by the author (1979) are discussed on the basis of the (RI) photometry available for these objects. Pending subsequent discussions of data contained in two additional catalogs, it is concluded that the first catalog contains 100 subdwarfs extending to an infrared magnitude of +11.5 mag. If these are halo objects, the number density-luminosity function has a steeper slope than the general luminosity function, indicating that the mass density may be greater than normally recognized. The luminosity law for the old disk stars in this catalog closely conforms to the slope of the general luminosity function from visual magnitude +4.5 to +13; however, there is an excess of stars of lower luminosity. Publication: The Astrophysical Journal Pub Date: June 1979 DOI: 10.1086/157138 Bibcode: 1979ApJ...230..786E Keywords: Astronomical Catalogs; Stellar Luminosity; Stellar Motions; Subdwarf Stars; Calibrating; Disks (Shapes); Halos; Infrared Spectra; Luminous Intensity; Radial Velocity; Stellar Mass; Stellar Spectrophotometry; Astronomy; Luminosities:Proper-Motion Stars; Luminosities:Subdwarfs; Proper-Motion Stars:Motions full text sources ADS | data products SIMBAD (324) Related Materials (1) Part 2: 1983ApJS...51..183E

ON G.P. Kuiper's Work on the Stars of Large Proper Motion

The writer is preparing for publication a complete listing of the late G.P. Kuiper's spectral classifications of stars of large proper motion north of δ=−50°. This work, resulting from his observations made at the Yerkes and McDonald Observatories some 35 years ago, has been only partially published; it is estimated that useful unpublished classifications exist for the order of 1000 stars. This paper discusses the background of his program and the procedures to be followed in making these data generally available.

The mass of the galactic halo derived from the luminosity function of high-velocity stars

view Abstract Citations (180) References (35) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The mass of the galactic halo derived from the luminosity function of high-velocity stars. Schmidt, M. Abstract The local luminosity function of high-velocity stars is derived on the basis of a complete sample of stars of large proper motion with trigonometric parallaxes. The fraction of these stars belonging to a roughly spherical galactic halo is deduced by using a kinematical criterion based on space velocities of metal-poor RR Lyrae variables. The local mass density of halo stars is about 1.7 x 10- solar masses per cubic parsec, corresponding to a fractional mass within the Sun's distance from the center of 6 percent, i.e., an order of magnitude lower than that of the massive halo proposed by Ostriker and Peebles. Subject headings: galactic structure - high-velocity stars - luminosity function - proper-motion stars - stellar statistics Publication: The Astrophysical Journal Pub Date: November 1975 DOI: 10.1086/153949 Bibcode: 1975ApJ...202...22S Keywords: Galactic Structure; Stellar Luminosity; Stellar Mass; Velocity Distribution; Astronomical Models; Galactic Radiation; Mass Distribution; Star Distribution; Stellar Evolution; Stellar Motions; Astrophysics full text sources ADS | data products SIMBAD (57)

UBV PHOTOMETRY OF LARGE PROPER MOTION STARS.

ABSTRACT The results of UBV photometry for 32 large proper motion stars are presented in Table I. The (B- V) vs. (U- B) diagram (Fig. 1) is used to select probable subluminous stars. Table III presents the stars which are nearer than 20 pc according to their photometric parallaxes. Key words: UBV photometry - large proper motion stars - subluminous stars - nearby stars

The Faint End of the Main Sequence

New infrared observations of the two faintest known, late M dwarfs, Wolf 359 and +4°4048B (=VB 10) provide accurate luminosities and moderately well-determined temperatures (2500° and 2250° K, respectively). The photometric observations are fitted to a blackbody energy distribution on the assumption that line and band blocking affect most of the spectrum below 1 μ; the temperature structure is taken as that of a gray body. The resulting data, together with Johnson's observations for dM4 and dM5 stars, which have been reanalyzed, calibrate the faint end of the main sequence, with results given in a table and a figure. The bolometric corrections are very large and increase steeply to 6 mag, so that the faintest known stars are, in fact, not very faint; Wolf 359 has L = 13 X 10^(-4) L_☉, and VB 10 has L = 5 X 10^(-4) L_☉. A statistical discussion of Luyten's faint red stars of large proper motion gives L = 4 X 10^(-4) L_☉. With a conventional mass-luminosity relation, ℳ ≥ 0.09 ℳ_☉ , for stars of known luminosity. Stars of still lower mass, such as L726-8, are difficult to interpret.

New subdwarfs. II. Radial velocities, photometry, and preliminary space motions for 112 stars with large proper motion

view Abstract Citations (242) References (68) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS New subdwarfs 2 Radial velocities, photometry and preleminary space motions for 112 stars with large proper motion. Sandage, A. Abstract Radial velocities have been measured for 112 stars of large proper motion selected from an unpublished photometric catalog which contains 300 new subdwarf candidates The accuracy of the radial velocities is generally better than ± 2 km sec'. Nine possible velocity variables have been found, four of which are almost certain cases. Two particularly interesting variables (G9- 16, G26-9) probably have blue subluminous companions which are brighter than white dwarfs but considerably fainter than main- sequence stars. Space motions for all stars are shown in a Bottlinger diagram. The asymmetrical-drift velocity and the dispersions in U and W increase systematically with decreasing metal abundance for the entire range of ultraviolet excess values from ô = 0.00 to ~ = 0.31 mag The results are interpreted in terms of a chemical gradient perpendicular to the galactic plane. Many globular-clusterlike subgiants are present in the material. Candidates are listed to aid future spectroscopic studies. The existence of subdwarfs possessing high angular momentum which lead the Sun in its galactic rotational velocity seems to be established. There may be a systematic variation of metal abundance with increasingly positive V velocity, but more subdwarfs of this type are needed to establish the correlation. Candidates can be found in proper-motion catalogs from among stars whose proper-motion angles are directed away from the high-velocity antapex. A procedure is given to correct observed ultraviolet excess values for stars with the same metal abun- dance but of different colors for the effect of the guillotine Publication: The Astrophysical Journal Pub Date: December 1969 DOI: 10.1086/150271 Bibcode: 1969ApJ...158.1115S full text sources ADS | data products SIMBAD (113) GCPD (1) Related Materials (5) Part 1: 1964ApJ...139..442S Part 3: 1981AJ.....86.1643S Part 4: 1986AJ.....91.1140S Part 5: 1986AJ.....91.1189F Part 6: 1987AJ.....93...74S

Parallaxes of Two Stars of Large Proper Motion

Parallaxes of Two Stars of Large Proper Motion

Determinations of Color Classes for 204 Stars of Large Proper Motion.

Determinations of Color Classes for 204 Stars of Large Proper Motion.

Radial Velocities and Spectral Classes for Some Stars of Large Proper Motion

Radial Velocities and Spectral Classes for Some Stars of Large Proper Motion

Preliminary Color Indices for Stars of Large Proper Motion. II.

view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Preliminary Color Indices for Stars of Large Proper Motion. II. Luyten, Willem J. ; Dartayet, Martin Abstract Approximate color indices are given for 111 stars south of declination - 48° having proper motions greater than O'~5 annually and for 514 similar stars with smaller proper motions. Seven new white dwarfs and a number of possible "intermediates" are indicated among these stars Publication: The Astrophysical Journal Pub Date: September 1945 DOI: 10.1086/144750 Bibcode: 1945ApJ...102..196L full text sources ADS |

Radial Velocities of Proper-Motion Stars.

view Abstract Citations (19) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Radial Velocities of Proper-Motion Stars. Münch, Guido Abstract Radial velocities have been determined for 39 stars of large proper motion. New spectral types are given, except for the M dwarfs and the white dwarfs. For these, Kuiper's spectral types have been adopted. Three dwarfs have the H and K lines of Ca ii in emission, and one of these (BD+55 °1823, Ml) also shows the hydrogen lines in emission Publication: The Astrophysical Journal Pub Date: May 1944 DOI: 10.1086/144618 Bibcode: 1944ApJ....99..271M full text sources ADS |

Preliminary Color Indices for Stars of Large Proper Motion.

view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Preliminary Color Indices for Stars of Large Proper Motion. Luyten, Willem J. ; Dartayet, Martin Abstract Approximate color indices are given for seventy-eight stars south of declination - 48° having proper motions greater than O'~5 annually. A preliminary discussion follows of the very rough color indices of other stars, with much smaller proper motions, found on the same plates Publication: The Astrophysical Journal Pub Date: July 1942 DOI: 10.1086/144432 Bibcode: 1942ApJ....96...55L full text sources ADS | data products SIMBAD (26)