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Investigations of Stephenson's Hα stars
Hitherto unstudied objects from Stephenson's list of Hα emissionline objects at high galactic latitude were observed spectroscopicallyto prove their nature. 9 out of 11 objects show Hα in emission.Spectroscopy combined with photometric information indicates most ofthem being classical Be stars, while one object is a Post-AGB star andone a T-Tauri star. The classification of two objects, which are showingHα in emission, is unclear.
| New H-alpha emission stars found above 10 deg galactic latitude
Approximately 1300 5.2 x 5.2 deg red-sensitive objective prism plateshave been searched for H-alpha emission stars in order to complete thesearch of the entire sky. The survey here reported represents 59 percentof the whole sky, defined by the region north of declination -25 deg andmostly further than 10 deg from the Galactic plane; the omitted portionshad already been surveyed, in part at Warner and Swasey, in partelsewhere. Two hundred and six stars have been newly found, mostly ofunknown spectral type. The stars' latitude distribution suggests thatthey are mainly moderately high luminosity disk population stars. Thereare new finds especially in Orion and the Taurus dark clouds (limitingmag of about 13).
| Objective-prism discoveries in the northern sky - II.
Five tables list the observed characteristics of 244 northern hemispherestars recorded in 100 108 A/mm dispersion plates at H-gamma wavelengths.The 5 x 5 deg fields contained a number of suspected weak-metal objects.Listings are divided into peculiar A stars, metallic line and deltaDelphini stars, high luminosity objects, Ca II emission stars of the Gand K type, and composite spectra.
| The S201 far-ultraviolet imaging survey. II - A field in Cygnus
Far-ultraviolet imagery of a region in Cygnus, a 20 deg diameter fieldcentered near (1950) R. A. 21 h 31.2 m decl. +37 deg 25 arcmin, wasobtained by the S201 far-ultraviolet camera during the Apollo 16mission. In a 10 minute exposure covering the 1250-1600 A wavelengthrange (effective wavelength 1400 A), 730 star images can be detected,corresponding to a limiting ultraviolet magnitude of about m (1400) =10. Assuming nominal interstellar extinction values in this region nearthe galactic plane, this result corresponds to the detection of A0 Vstars to a distance of 300 pc and of B0 V stars to 1500 pc.Uncertainties in spectral classification and interstellar extinction forindividual objects are probably more significant than calibration ormeasurement errors. Most of the objects detected are identified withstars in the Smithsonian Astrophysical Observatory Star Catalog (1966),or the Catalog of Stellar Identifications (1979) or both, but 87 objectsremain unidentified (or are identified with late-type stars).
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Membre dels grups següents:
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Dades d'Observació i Astrometria
| Constel·lació: | Cygnus |
| Ascensió Recta: | 21h47m40.86s |
| Declinació: | +31°31'42.3" |
| Magnitud Aparent: | 8.436 |
| Distancia: | 3571.429 parsecs |
| Moviment propi RA: | 0.4 |
| Moviment propi Dec: | -4.3 |
| B-T magnitude: | 8.371 |
| V-T magnitude: | 8.431 |
Catàlegs i designacions:
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