New periodic variables from the Hipparcos epoch photometry Two selection statistics are used to extract new candidate periodicvariables from the epoch photometry of the Hipparcos catalogue. Theprimary selection criterion is a signal-to-noise ratio. The dependenceof this statistic on the number of observations is calibrated usingabout 30000 randomly permuted Hipparcos data sets. A significance levelof 0.1 per cent is used to extract a first batch of candidate variables.The second criterion requires that the optimal frequency be unaffectedif the data are de-trended by low-order polynomials. We find 2675 newcandidate periodic variables, of which the majority (2082) are from theHipparcos`unsolved' variables. Potential problems with theinterpretation of the data (e.g. aliasing) are discussed.
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Photoelectric photometry of stars in the Vilnius system in Kapteyn areas SA 2, 4 and 6 Photoelectric photometry in the Vilnius system of 114 standard stars inKapteyn areas SA 2, 4, and 6 is presented with mean square errors of thearithmetic mean +/- 0.005 mag. Photometrically determined spectral typesand luminosity classes of the stars are also presented.
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H-beta photometry of northern intermediate galactic latitude early-type stars and galactic structure away from the plane Photoelectric H-beta photometry is presented for 255 early-type stars atintermediate galactic latitudes. Absolute magnitudes and distances arederived for the more luminous stars. Those with visual magnitudes lessthan or equal to 2.5 and at distances of up to 1 kpc from the galacticplane may follow the spiral structure in the plane.
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UBV photometry and MK spectral classification of northern early-type stars at intermediate galactic latitudes Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977MNRAS.180..691H&db_key=AST
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Observations of the Spatial Structure of Interstellar Hydrogen. II. Optical Determination of Distances in a Small Region Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970ApJ...160...59A&db_key=AST
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