A Cold Nearby Cloud inside the Local Bubble
The high-latitude Galactic H I cloud toward the extragalactic radiosource 3C 225 is characterized by very narrow 21 cm emission andabsorption indicative of a very low H I spin temperature of about 20 K.Through high-resolution optical spectroscopy, we report the detection ofstrong, very narrow Na I absorption corresponding to this cloud toward anumber of nearby stars. Assuming that the turbulent H I and Na I motionsare similar, we derive a cloud temperature of20+6-8 K (in complete agreement with the 21 cmresults) and a line-of-sight turbulent velocity of 0.37+/-0.08 kms-1 from a comparison of the H I and Na I absorption linewidths. We also place a firm upper limit of 45 pc on the distance of thecloud, which situates it well inside the Local Bubble in this directionand makes it the nearest known cold diffuse cloud discovered to date.
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Radial velocities. Measurements of 2800 B2-F5 stars for HIPPARCOS
Radial velocities have been determined for a sample of 2930 B2-F5 stars,95% observed by the Hipparcos satellite in the north hemisphere and 80%without reliable radial velocity up to now. Observations were obtainedat the Observatoire de Haute Provence with a dispersion of 80Ä,mm(-1) with the aim of studying stellar and galactic dynamics.Radial velocities have been measured by correlation with templates ofthe same spectral class. The mean obtained precision is 3.0 km s(-1)with three observations. A new MK spectral classification is estimatedfor all stars. Based on observations made at the Haute ProvenceObservatory, France and on data from The Hipparcos Catalogue, ESA.Tables 4, 5 and 6 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr or viahttp://cdsweb.u-strasbg.fr/Abstract.htm
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Radial velocity measurements. I - Ground-based observations of the program stars for the HIPPARCOS satellite
The radial velocities of 272 stars brighter than m(pg) = 8.5 aredetermined by digital microphotometric measurement of plates obtainedwith dispersion 80 A/mm using the Marly slit spectrograph on the 120-cmtelescope of the Observatoire de Haute Provence. The objects wereselected as probable members of the input catalog for the ESA Hipparcosastrometric satellite. The measurement techniques and data-reductionprocedures are described in detail, and the results are presented inextensive tables and graphs and briefly characterized.
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A study of visual double stars with early type primaries. IV Astrophysical data
Astrophysical parameters (MK class, color excess, absolute magnitude,distance, effective temperature, mass, and age) are derived fromcalibrations of the uvby-beta indices for the members of 253 doublestars with O or B type primaries and faint secondaries. The photometricspectral classification is compared to the MK classes, and the agreementis very good. The derived data together with spectroscopic and JHKL dataare used for deciding which pairs are likely to be physical and whichare optical, and it is shown that 98 (34 percent) of the secondaries arelikely to be members of physical systems. For 90 percent of the physicalpairs the projected separation between the components is less than25,000 AU. A majority of the physical secondaries are late-type stars,and 50 percent of them are contracting towards the zero-agemain-sequence. Also presented are new uvby-beta data for 43 secondariesand a computer program for determining astrophysical parameters fromuvby-beta data.
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The galactic reddening law - The evidence from uvby-beta photometry of B stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1985A&A...142..189T&db_key=AST
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A study of visual double stars with early type primaries. II - Photometric results
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1983A&AS...51..161L&db_key=AST
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A study of visual double stars with early type primaries. I - Spectroscopic results
Attention is given to spectral peculiarities found in data on thespectral classes of 486 stars in 254 visual doublet or multiplet systemswith O or B type primaries, in order to isolate a group of very youngstars that may serve for the study of early stellar evolutioncharacteristics. It is noted that the material contains a substantialfraction of secondaries that are likely to be physical, and that severalof these may be in the premain-sequence phase of stellar evolution, orhave reached the zero-age main sequence.
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Cloudcroft occulation summary. II - April 1980-December 1981
Lunar occultation observations obtained between April 1980 and December1981 at Cloudcroft Observatory are summarized. 24 of the 75 occulationsreported involve stars brighter than seventh magnitude. Although noangular diameter measurements are included, six observations arepresented which indicate duplicity; three of these stars are known orsuspected binaries, and the others are apparently new discoveries.Occultation observations of the Galilean satellites obtained on 16 July1980 and results from the Hyades passage of 19 September 1981 areincluded.
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Lunar Occultation Summary. I
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974ApJS...28..405E&db_key=AST
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Photoelectric measurements of lunar occultation. VI. Further observational results.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973AJ.....78..482D&db_key=AST
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The Arcturus Group
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971PASP...83..271E&db_key=AST
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INHABITED SKY
