Vela OB1: Probable New Members and Hertzsprung-Russell Diagram
Several dozen stars are identified as probable previously unrecognizedmembers of the association Vel OB1, including the Vela X-1 binary pulsarsystem. Based on a variable extinction analysis of 70 stars, thedistance and ratio of total to selective absorption of the associationare determined to be 1750 pc and 3.70, respectively. Vel OB1 may besignificantly larger than previously appreciated, perhaps up to 600 by300 pc in the sense of longitude by latitude. This physical extent, andthe fact that the H-R diagram includes both low-mass evolved yellowsupergiants and massive, early-type supergiants, indicates that Vel OB1is probably not coeval.
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UBV beta Database for Case-Hamburg Northern and Southern Luminous Stars
A database of photoelectric UBV beta photometry for stars listed in theCase-Hamburg northern and southern Milky Way luminous stars surveys hasbeen compiled from the original research literature. Consisting of over16,000 observations of some 7300 stars from over 500 sources, thisdatabase constitutes the most complete compilation of such photometryavailable for intrinsically luminous stars around the Galactic plane.Over 5000 stars listed in the Case-Hamburg surveys still lackfundamental photometric data.
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A Radial Velocity Database for Stephenson-Sanduleak Southern Luminous Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....113..823R&db_key=AST
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A spectroscopic database for Stephenson-Sanduleak Southern Luminous Stars
A database of published spectral classifications for objects in theStepenson-Sanduleak Luminous Stars in the Southern Milky Way catalog hasbeen compiled from the literature. A total of 6182 classifications for2562 stars from 139 sources are incorporated.
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A homogeneous catalog of new UBV and H-beta photometry of B- and A-type stars in and around the Scorpius-Centaurus OB association
B- and A-type stars in and near the Sco-Cen OB association areinvestigated with UBV and H-beta photometry to acquire data relevant tothe luminosity function of Sco-Cen. The measurements generally consistof two 10-s integrations of U, B, V, (W, N) filters, and theobservations are corrected iteratively for atmospheric extinction andinstrumental response. The data presented give the mean V magnitude,mean B-V, mean U-B, and the estimated uncertainties for these values.The catalog provides a homogeneous catalog of data for a large fieldwith stellar objects delineating membership to the association Sco-Cenand that affect the luminosity function of the aggregate.
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Anomalous infrared emitters among A-type stars
Spectroscopic observations of a sample of 26 stars have been analyzed inthe blue and near-IR to find out if anomalous IR emitters (AIEs) have aspectral signature. It is found that many, but not all, such starsexhibit shell characteristics. Analysis of available IRAS photometricobservations of A-type stars shows that the detection of circumstellarfeatures depends strongly on the number of IR bands at which the objectwas observed. Out of the 707 stars observed by IRAS, 41 AIEs, or 5.7percent, are found. Among nonsupergiant AIEs, 23 percent show shellfeatures. The true percentage of AIEs among A-type stars is estimated tobe 1.5 percent in a volume-corrected sample. A list of 24 stars whichwere apparently not previously detected as AIEs is given.
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Secondary standards for H-beta photometry in the Southern Hemisphere (second series).
Not Available
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Secondary standards for H-beta photometry in the E regions.
Not Available
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UBV (RI)c standard stars in the E- and F-regions and in the Magellanic Clouds - a revised catalogue.
Not Available
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Secondary standards for the Stromgren UVBY system
Observations of 158 E region stars have been made in the Stromgrensystem, using the 46-cm reflector at Cape Town. They are mostly brighterthan eighth magnitude and are intended for use as secondary standardsfor the four-color system. The E region relative zero points are definedwith a precision of + or - 0.001 mag, and the internal standard errorsof the colors life between + or - 0.001 and + or - 0.002 mag.
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New UBVRI photometry for 900 supergiants
A description is presented of the results obtained in connection with asystematic program of supergiant photometry on the Johnson UBVRI system.During the eight years after the start of the program, almost 1000 starshave been observed, about 400 three or more times each. The originalselection of stars used the spectral type catalog of Jaschek et al.(1964) to choose supergiants. Since observations were possible from bothChile and Canada, no declination limits were imposed, and no particularselection criteria were imposed other than to eliminate carbon stars.These are so red as to require enormous extrapolations of thetransformation equations.
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UBV photometry for southern OB stars
New UBV photometry of 1227 OB stars in the southern Milky Way ispresented. For 1113 of these stars, MK spectral types have been reportedpreviously in a comprehensive survey to B = 10.0 mag.
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Variable Stars in the LSS Catalogue
Not Available
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Photometric standard stars for the UBV and (RI)KC systems.
Not Available
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Interstellar gas in the GUM Nebula
A survey of the interstellar gas near the Gum Nebula by opticalobservation of 67 stars at Ca II, 42 stars at Na I, and 14 stars in theUV with the Copernicus satellite provided radial velocities and columndensities for all resolved absorption components. Velocity dispersionsfor gas in the Gum Nebula are not significantly larger than in thegeneral interstellar medium; the ionization structure is predominantlythat of an H II region with moderately high ionization. Denser, morehighly ionized clouds are concentrated toward the Gum Nebula; theseclouds do not show the anomalously high ionization observed in the Velaremnant clouds.
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Prediction of spectral classification from photometric observations - Application of the UVBY beta photometry and the MK spectra classification. II - General case
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980A&A....85...93M&db_key=AST
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Prediction of spectral classification from photometric observations-application to the UVBY beta photometry and the MK spectral classification. I - Prediction assuming a luminosity class
An algorithm based on multiple stepwise and isotonic regressions isdeveloped for the prediction of spectral classification from photometricdata. The prediction assumes a luminosity class with reference touvbybeta photometry and the MK spectral classification. The precisionattained is about 90 percent and 80 percent probability of being withinone spectral subtype respectively for luminosity groups I and V and forluminosity groups III and IV. A list of stars for which discrepanciesappear between photometry and spectral classification is given.
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On the 4430 A interstellar band - A visual classification
A system of visual classification of the strength of the interstellarband 4430 A has been developed, based on spectra taken at spectralclassification dispersion. The intensity of the band was divided into 8main classes, defined by a group of selected standard stars. The systemwas applied to 1,111 southern OB stars contained in the catalog ofspectral types by Garrison, Hiltner, and Schild (1977). The mean errorin the classification was estimated to be plus or minus 1 class.Equivalent widths were measured for 100 stars; an excellent correlationwith the visual estimations was obtained. A calibration between thesetwo parameters is given.
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MK spectral classifications for southern OB stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977ApJS...35..111G&db_key=AST
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The spatial distribution of young stars in VELA (l=250 to 284).
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977A&AS...27..343D&db_key=AST
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Detection of errors in spectral classification by cluster analysis
Cluster analysis methods are applied to the photometric catalogue ofuvby-beta measurements by Hauck and Lindemann (1973) and point out 249stars the spectral type of which should be reconsidered or thephotometric indices of which should be redetermined.
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VRI standards in the E regions
Not Available
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Wavelength dependence of interstellar polarization and ratio of total to selective extinction
A multichannel polarimeter-photometer which uses dichroic filters toseparate the (UBVR) spectral regions is described. The instrument wasused with a 24-inch rotatable tube telescope for polarimetricobservation of nearby stars. Polarization data for 364 nearby stars aretabulated, together with the wavelength dependence of linear andinterstellar polarization.
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Standard Stars for VRI Photometry with S25 Response Photocathodes [Errata: 1974MNSSA..33....1C]
Not Available
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Investigation of a Milky Way field in Canis Major
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974AJ.....79.1022C&db_key=AST
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UBV Photometry of 500 Southern Stars [erratum: 1973MNSSA..32...48C]
Not Available
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New kinematical data for bright southern OB-stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972A&AS....5..129L&db_key=AST
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Four-color and H-beta photometry for bright B-type stars in the southern hemisphere.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971AJ.....76..621C&db_key=AST
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MK Spectral Types for Bright Southern OB Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1969ApJ...157..313H&db_key=AST
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UBV photometry of star clusters in the Magellanic Clouds.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1968AJ.....73..569V&db_key=AST
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INHABITED SKY
