HD 250540

VI photometry of selected SAO stars Johnson V- and I-band photoelectric photometry has been obtained for 158SAO stars in a continuing program in support of the Near InfraredPhotographic Sky Survey. These data are utilized in the calibration ofthe survey photographs and are presented here to assist other programsreliant upon access to photometry in the photographic infrared.
Evidence for an abundance gradient in the galactic disk DDO photometry of field K giants in distant parts of the galactic diskin the galactic center and anticenter directions is used together withDDO and UBV photometry of 41 open clusters to investigate the variationof metallicity across the galactic disk. Some problems in thecalibration of DDO photometry are examined, and the observations areanalyzed. The data are shown to be consistent with the suggestion thatthere is a composition gradient among stars of all ages in the galacticdisk. Specifically, it is found that: (1) the metallicity gradient inthe solar vicinity is approximately -0.05/kpc; (2) the gradient maybecome steeper beyond a galactocentric distance of approximately 11 kpc;(3) the nitrogen gradient is more pronounced than the overall gradient;and (4) the gradient in the youngest stellar population is probably notdramatically different from the overall gradient
Vitesses radiales dans 4 champs de petite latitude galactique. Not Available

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