Contents
Images
Upload your image
DSS Images Other Images
Related articles
Spectral Classification of Stars in A Supplement to the Bright Star Catalogue
MK spectral types are given for about 584 stars in A Supplement to theBright Star Catalogue. These are compared with Hipparcos parallaxes tocheck the reliability of those classifications. The estimated errors are+/-1.2 subtypes, and 10% of the luminosity classes may be wrong.
| First radial velocities for 146 bright F- and G-type stars
We have obtained an average of 5.7 radial velocities for 146 northernstars of types F and G (all luminosity classes) listed in 'A Supplementto the Bright Star Catalogue' as having no previously known radialvelocity measures. Those were obtained with charge coupled devices(CCDs) and a cross-correlation technique; the intrinsic velocityaccuracy, based on stars of apparently constant velocity, is probablyless than +/- 0.3 km/s per mean. Of those stars 14% are newly discoveredSB2 stars. The prevelance of rapid profile variations (in minutes orhours) in most of the broad-lined F-type stars makes it difficult toobtain accurate measures for them.
| Evolved GK stars near the sun. I - The old disk population
A sample of nearly two thousand GK giants with intermediate band, (R,I),DDO and Geneva photometry has been assembled. Astrometric data is alsoavailable for most of the stars. The some 800 members of the old diskpopulation in the sample yield accurate luminosities (from two sources),reddening values and chemical abundances from calibrations of thephotometric parameters. Less than one percent of the objects arepeculiar in the sense that the flux distribution is abnormal. Thepeculiarity is signaled by strong CH (and Ba II) and weak CH. The CH+stars are all spectroscopic binaries, probably with white dwarfcompanions, whereas the CH- stars are not. A broad absorption band,centered near 3500 A, is found in the CH+ stars whereas the CH- objectshave a broad emission feature in the same region. The intensity of theseabsorptions and emissions are independent of the intensity of abnormalspectral features. Ten percent of the old disk sample have a heavyelement abundance from one and a half to three times the solar value.The distribution of the heavy element abundances is nearly a normal onewith a peak near solar abundance and ranges three times to one sixthsolar. The distribution of the (U, V) velocities is independent of theheavy element abundance and does not appear to be random. Ten percent ofthe old disk stars show a CN anomaly, equally divided between CN strongand CN weak. Several stars of individual astrometric or astrophysicalimportance are isolated.
| A critical appraisal of published values of (Fe/H) for K II-IV stars
'Primary' (Fe/H) averages are presented for 373 evolved K stars ofluminosity classes II-IV and (Fe/H) values beween -0.9 and +0.21 dex.The data define a 'consensus' zero point with a precision of + or -0.018 dex and have rms errors per datum which are typically 0.08-0.16dex. The primary data base makes recalibration possible for the large(Fe/H) catalogs of Hansen and Kjaergaard (1971) and Brown et al. (1989).A set of (Fe/H) standard stars and a new DDO calibration are given whichhave rms of 0.07 dex or less for the standard star data. For normal Kgiants, CN-based values of (Fe/H) turn out to be more precise than manyhigh-dispersion results. Some zero-point errors in the latter are alsofound and new examples of continuum-placement problems appear. Thushigh-dispersion results are not invariably superior to photometricmetallicities. A review of high-dispersion and related work onsupermetallicity in K III-IV star is also given.
| Common proper motion stars in the AGK 3
A search was made of common-proper-motion (CPM) systems among AGK 3stars. The selection of physical systems was based upon the ratiobetween the angular separation (rho) and the proper motion (mu); the CPMstars found are presented in two tables. Table I lists systems withrho/mu less than 1000 years. It contains 326 entries, and the proportionof optical pairs is estimated to be 1 percent. Table II lists systemswith rho/mu in the range 1000 to 3500 years; it contains 113 systems,but only 60 percent of them are physical. Nevertheless, these systemsoften have separations larger than 10,000 AU and are the mostinteresting for the study of the tail of the distribution function ofthe semimajor axes.
| The Luminosities of Late-Type Stars of Differing Metal Abundance
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972ApJ...177..665J&db_key=AST
| Determination of atmospheric parameters for G and K giants by means of photoelectric indices.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971A&A....15..123H&db_key=AST
|
Submit a new article
Related links
Submit a new link
Member of following groups:
|
Observation and Astrometry data
| Constellation: | ヘルクレス座 |
| Right ascension: | 16h31m30.62s |
| Declination: | +08°17'38.8" |
| Apparent magnitude: | 6.971 |
| Distance: | 80.906 parsecs |
| Proper motion RA: | 36.5 |
| Proper motion Dec: | 71.3 |
| B-T magnitude: | 8.117 |
| V-T magnitude: | 7.066 |
Catalogs and designations:
|
