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Far-Ultraviolet Stellar Photometry: Fields Centered on rho Ophiuchi and the Galactic Center
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996ApJS..104..101S&db_key=AST
| Far-ultraviolet stellar photometry: Fields in Sagittarius and Scorpius
Far-ultraviolet photometry for 741 objects in a field in Sagittariuscentered near M8 and 541 objects in a field centered near sigma Scorpiiis presented. These data were extracted from electographic imagesobtained with two cameras during a shuttle flight in 1991 April/May. Thecameras provided band passes with lambdaeff = 1375 A andlambdaeff = 1781 A. Synthetic colors show that these bandsare sensitive to effective temperature for hot stars. Our measurementswere placed on a quantitative far-ultraviolet magnitude scale byconvolving the spectra of stars observed by IUE with our cameras'spectral response functions. Fifty-eight percent of the ultravioletobjects were identified with visible stars using the SIMBAD databasewhile another 40% of the objects are blends of early type stars tooclose together to separate with our resolution. Our photometry iscompared with that from the TD-1, OAO 2, and ANS satellites and the S201(Apollo 16) far-ultraviolet camera and found to agree at the level of afew tenths of a magnitude. Unlike previous studies, almost half of theidentified visual counterparts to the ultraviolet objects are early Bstars. A plot of distance modulus against ultraviolet color excessreveals a significant population of stars with strong ultravioletexcess.
| 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.
| Walraven photometry of nearby southern OB associations
Homogeneous Walraven (VBLUW) photometry is presented for 5260 stars inthe regions of five nearby southern OB associations: Scorpio Centaurus(Sco OB2), Orion OB1, Canis Major OB1, Monoceros OB1, and Scutum OB2.Derived V and (B - V) in the Johnson system are included.
| 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.
| Search for Beta Cephei stars south of declination -20 deg. II - Photometric and spectrographic observations of early B giants and subgiants - Winter objects
Results of the second part of a program begun in 1975 (Jerzykiewicz andSterken, 1977) are presented. Out of 39 Beta Cephei candidates observedphotometrically, seven turned out to vary with the b ranges exceeding0.020 m, while 21 have been found constant to within 0.010 m or better.For the 56 comparison stars these numbers are 6 and 25, respectively.From spectrographic observations one of the candidates, HD 129557 = HR5488 (B2 III), iis found to be a Beta Cephei variable with a period of0.135 d and the 2 K amplitude of 18.4 km/s. A comparison of the resultsof this program with other recent photometric searches for Beta Cepheivariables shows good agreement in most cases. There are severaldiscrepant stars, however. These are discussed in some detail. Aconclusion emerges that in the low temperature extension of the BetaCephei region, if such an extension exists at all, on-and-off typepulsations occur.
| 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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Gözlemler ve gökölçümü verileri
| Takýmyýldýz: | Akrep |
| Sað Açýklýk: | 16h40m37.85s |
| Yükselim: | -35°41'13.8" |
| Görünürdeki Parlaklýk: | 6.64 |
| Uzaklýk: | 200 parsek |
| özdevim Sað Açýklýk: | -2.7 |
| özdevim Yükselim: | -6.7 |
| B-T magnitude: | 6.826 |
| V-T magnitude: | 6.656 |
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