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Stroemgren photometry of F- and G-type stars brighter than V = 9.6. I. UVBY photometry
Within the framework of a large photometric observing program, designedto investigate the Galaxy's structure and evolution, Hβ photometryis being made for about 9000 stars. As a by-product, supplementary uvbyphotometry has been made. The results are presented in a cataloguecontaining 6924 uvby observations of 6190 stars, all south ofδ=+38deg. The overall internal rms errors of one observation(transformed to the standard system) of a program star in the interval6.5
| Estimation of spectral classifications for bright northern stars with interesting Stromgren indices
The purpose of this investigation is to provide spectroscopic observerswith finding lists of potentially interesting objects. From anunpublished UVBY catalogue of 7026 northern stars (mostly brighter than8.3m) 1094 objects with interesting combinations of UVBY indices havebeen selected. Most stars with post-HD classifications have beenexcluded, as well as late F dwarfs belonging to the intermediatepopulation II. For the 792 remaining stars estimated spectralclassifications are given. The techniques and experience from a previouspaper dealing with southern stars have been utilized here. Among thepredicted spectral classifications are 40 OB stars; 262 Ap, Am, or Fmstars; 16 supergiants of types A to G; 110 bright giants of types A to K(class II); 156 double stars or objects with composite spectra; 26 lateF dwarfs; 91 weak-lined dwarf and giant stars of types F to K, includingearly F-type population II field blue stragglers; and a few possiblefield horizontal branch stars, lambda Bootis-type stars, and late-typehalo giants.
| Photometrical analysis of the June 30, 1973 solar corona
In order to deduce reliable values of the K and F coronal, a method ofphotographic photometry has been applied to study compensatedhigh-resolution pictures obtained during the June 30, 1973, solar totaleclipse, including a color one. The correctly exposed images ofcalibration stars are used to obtain intensities in units of the meanbrightness of the sun. An account is made, in both the blue and the redspectral ranges, for the sky background as well as for the coronalaureola effects. The N-polar and E-equatorial regions are shown to berelatively homogeneous; their intensities are especially studied in theradial direction and compared with published values of the K and Fcoronae. No flattening and no color effect are found in the inner part(distance less than 2.5 solar radii) of the F corona.
| Gravitational deflection of light : solar eclipse of 30 June 1973.2 Plate reductions.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976AJ.....81..455J&db_key=AST
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Membre dels grups següents:
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Dades d'Observació i Astrometria
| Constel·lació: | Gemini |
| Ascensió Recta: | 06h40m05.36s |
| Declinació: | +23°40'25.5" |
| Magnitud Aparent: | 7.415 |
| Distancia: | 206.186 parsecs |
| Moviment propi RA: | 11.3 |
| Moviment propi Dec: | -17.5 |
| B-T magnitude: | 7.937 |
| V-T magnitude: | 7.459 |
Catàlegs i designacions:
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