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The Near-Infrared Size-Luminosity Relations for Herbig Ae/Be Disks
We report the results of a sensitive K-band survey of Herbig Ae/Be disksizes using the 85 m baseline Keck Interferometer. Targets were chosento span the maximum range of stellar properties to probe the disk sizedependence on luminosity and effective temperature. For most targets,the measured near-infrared sizes (ranging from 0.2 to 4 AU) support asimple disk model possessing a central optically thin (dust-free)cavity, ringed by hot dust emitting at the expected sublimationtemperatures (Ts~1000-1500 K). Furthermore, we find a tightcorrelation of disk size with source luminosity R~L1/2 for Aeand late Be systems (valid over more than two decades in luminosity),confirming earlier suggestions based on lower quality data.Interestingly, the inferred dust-free inner cavities of the highestluminosity sources (Herbig B0-B3 stars) are undersized compared topredictions of the ``optically thin cavity'' model, likely because ofoptically thick gas within the inner AU.
| The Tokyo PMC catalog 90-93: Catalog of positions of 6649 stars observed in 1990 through 1993 with Tokyo photoelectric meridian circle
The sixth annual catalog of the Tokyo Photoelectric Meridian Circle(PMC) is presented for 6649 stars which were observed at least two timesin January 1990 through March 1993. The mean positions of the starsobserved are given in the catalog at the corresponding mean epochs ofobservations of individual stars. The coordinates of the catalog arebased on the FK5 system, and referred to the equinox and equator ofJ2000.0. The mean local deviations of the observed positions from theFK5 catalog positions are constructed for the basic FK5 stars to comparewith those of the Tokyo PMC Catalog 89 and preliminary Hipparcos resultsof H30.
| 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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| Takýmyýldýz: | Terazi |
| Sað Açýklýk: | 15h41m15.97s |
| Yükselim: | -13°58'13.1" |
| Görünürdeki Parlaklýk: | 6.865 |
| Uzaklýk: | 160.514 parsek |
| özdevim Sað Açýklýk: | 0 |
| özdevim Yükselim: | -5.2 |
| B-T magnitude: | 6.924 |
| V-T magnitude: | 6.87 |
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