Садржај
Слике
Уплоадјуј своје слике
DSS Images Other Images
Везани чланци
An astrometric catalogue for the area of Coma Berenices
A catalogue of stellar positions and proper motions down to the 14thphotographic magnitude in the area of the open cluster in Coma Berenicesis compiled from data of 12 different sources. The accuracy of theproper motion data is comparable to that of the Hipparcos Catalogue. Thecatalogue Table 5 is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Strong-lined G dwarfs in the galactic disk
Using a quantitative, three-dimensional spectral classification systemdeveloped earlier (Rose 1984), a class of strong lined dwarf stars hasbeen identified in the Galactic disk. The strong-lined dwarfs were foundin a sample of G5-G7 stars with m(B) of about 11 classified as giants byUpgren (1962) in his North Galactic Pole survey. The misclassificationin luminosity on Upgren objective-prism spectra results from the greatstrength of the CN bands in these stars. The strong-lined stars aredetermined to be dwarfs from a measurement of the strength of Sr II 4077A relative to neighboring Fe I lines. Furthermore, these stars are foundto be strong lined in Fe and to have anomalous broadband colors thatsuggest heavy line blanketing. They have properties similar to starswith Fe/H abundance ratios + 0.25 in the Cayrel de Strobel and Bentolila(1983) Fe/H abundance catalog. The strong lined dwarfs contribute about25 percent of the G5-G7 dwarfs at m(B) of about 11 in the Upgren survey.However, there is a selection bias in favor of the strong-lined dwarfs,since they are hotter, and hence more luminous, than solar-abundancedwarfs of the same spectral type. When this selection effect isaccounted for, it is found that the strong lined stars comprise about 15percent of the Galactic disk.
| Red horizontal-branch stars in the galactic disk
A quantitative, three-dimensional spectral classification systemdeveloped by Rose (1984), which uses 2.5-A resolution spectra in theblue, has been used to identify a class of red horizontal branch (RHB)stars in the Galactic disk that are similar to those in the 'metal rich'globular cluster M 71. The RHB are denoted as evolved stars by their SrII 4077 line, and are distinguished from post-main sequence starsevolving through the same region of the HR diagram on the basis of theunique appearance of their CN 3883 and 4216 A bands. The RHB starsconsitute at least 5 percent of the entire giant branch population ofthe disk.
| Narrow-band photometry of G and K stars near the North Galactic Pole
Photoelectric narrow-band photometry obtained for 292 late-type starsbrighter than 10 m in the North Galactic Pole area is discussed. The g,n, k, m, f-system of Dickow et al. (1970) is used. The stars were chosenfrom two lists: (1) all stars of spectral type G5 or later in the HenryDraper Catalog (Cannon and Pickering, 1918-1924) within 15 deg of theNorth Galactic Pole, together with a few BD stars; and (2) all starsclassified as K or M giants and in Upgren's 25-31 deg zones (Upgren,1962). For most of the stars, estimates of the following quantities arederived: V-magnitude, R-I color, metal abundance, MV, and theduplicity parameter res(k).
| Spectra of Upgren's unclassified stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972AJ.....77..669S&db_key=AST
| Upgren's unclassified stars A: a new type of G-giant stars ?
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971AJ.....76..334S&db_key=AST
| The space distribution of late type stars in a North galactic pole region.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1962AJ.....67...37U&db_key=AST
|
Додај нови чланак
Линкови у сродству са темом
Додај нови линк
Чланови следећих група \:
|
Посматрања и Астрометриски подаци
Каталог и designations:
|
