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VLT K-band spectroscopy of massive stars deeply embedded in IRAS sources with UCHII colours
We have obtained high resolution (R = 10 000) K-band spectra ofcandidate young massive stars deeply embedded in (ultra-) compact H IIregions (UCHIIs). These objects were selected from a near-infraredsurvey of 44 fields centered on IRAS sources with UCHII colours. Often,the near-infrared counterpart of the IRAS source is a young embeddedcluster hosting massive stars. In these clusters, three types of objectsare identified. The first type (38 objects) consists of "naked" OB starswhose K-band spectra are dominated by photospheric emission. We classifythe K-band spectra of the OB-type cluster members using near-infraredclassification criteria. A few of them have a very early (O3-O4 V)spectral type, consistent with a young age of the embedded clusters. Thespectral classification provides an important constraint on the distanceto the embedded cluster. The ionising power of the population thusderived is compared to the information obtained from the infrared andradio flux of these sources. In most cases these two differentdeterminations of the ionising flux are consistent, from which weconclude that we have identified the ionising star(s) in about 50% ofthe embedded clusters. The second type (7 objects) are point sourcesassociated with UCHII radio emission, that exhibit nebular emissionlines in the near-infrared. Six of the objects in this group produce HeI emission indicative of an embedded O-type star. These objects are moreembedded than the OB stars and probably do not dominate the infraredflux as measured by IRAS. They may emit the bulk of their reprocessed UVradiation at mm wavelengths. The third type (20 objects) ischaracterised by broad (100-200 km s-1) Brγ emissionand no photospheric absorption profiles. Bik et al. (2005, A&A,submitted) show that these objects are massive YSO candidates surroundedby dense circumstellar disks.
| A catalog of far-ultraviolet point sources detected with the fast FAUST Telescope on ATLAS-1
We list the photometric measurements of point sources made by the FarUltraviolet Space Telescope (FAUST) when it flew on the ATLAS-1 spaceshuttle mission. The list contains 4698 Galactic and extragalacticobjects detected in 22 wide-field images of the sky. At the locationssurveyed, this catalog reaches a limiting magnitude approximately afactor of 10 fainter than the previous UV all-sky survey, TDl. Thecatalog limit is approximately 1 x 10-14 ergs A sq cm/s,although it is not complete to this level. We list for each object theposition, FUV flux, the error in flux, and where possible anidentification from catalogs of nearby stars and galaxies. Thesecatalogs include the Michigan HD (MHD) and HD, SAO, the HIPPARCOS InputCatalog, the Position and Proper Motion Catalog, the TD1 Catalog, theMcCook and Sion Catalog of white dwarfs, and the RC3 Catalog ofGalaxies. We identify 2239 FAUST sources with objects in the stellarcatalogs and 172 with galaxies in the RC3 catalog. We estimate thenumber of sources with incorrect identifications to be less than 2%.
| Photometry of F-K type bright giants and supergiants. I - Intermediate band and H-Beta observations
Over 1500 observations of 560 bright giants and supergiants of types F-Kare presented and compared to the observations by Gray and Olsen (1991).The present results include intermediate-band which is slightlydifferent from the Stromgren data by Gray and Olsen due to a differentwidth for the v filter. A systematic difference in m(1) - M(1) withdecreasing temperature is noted in the two H-Beta data sets, and thecorrelations are defined.
| Photometry of F-K type bright giant and supergiants. II - Calibration on indices in terms of luminosity reddening and abundance of F-type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1991AJ....102.1826E&db_key=AST
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Pozíciós és asztrometriai adatok
| Csillagkép: | Hajófar |
| Rektaszcenzió: | 07h59m16.71s |
| Deklináció: | -16°50'46.9" |
| Vizuális fényesség: | 8.561 |
| Távolság: | 289.017 parszek |
| RA sajátmozgás: | -11.1 |
| Dec sajátmozgás: | 6.1 |
| B-T magnitude: | 8.645 |
| V-T magnitude: | 8.568 |
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