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The qWR star HD 45166 . I. Observations and system parameters
The binary star HD 45166 has been observed since 1922but its orbital period has not yet been found. It is considered apeculiar Wolf-Rayet star, and its assigned classification has varied.For this reason we included the object as a candidate V Sge star andperformed spectroscopy in order to search for its putative orbitalperiod. High-resolution spectroscopic observations show that thespectrum, in emission and in absorption, is quite rich. The emissionlines have great diversity of widths and profiles. The full widths athalf maximum vary from 70 km s-1 for the weakest lines up to370 km s-1 for the most intense ones. The hydrogen and heliumlines are systematically broader than the CNO lines. Assuming thatHD 45166 is a double-line spectroscopic binary, itpresents an orbital period of P = 1.596 ± 0.003 day, with aneccentricity of e = 0.18 ± 0.08. In addition, a search forperiodicity using standard techniques reveals that the emission linespresent at least two other periods, of 5 and 15 h. The secondary starhas a spectral type of B7 V and, therefore, should have a mass of aboutM2 = 4.8 ~Mȯ. Given the radial velocityamplitudes, we determined the mass of the hot (primary) star asM1 = 4.2 ± 0.7~Mȯ and the inclinationangle of the system, i = 0.77° ± 0.09°. As theeccentricity of the orbit is non zero, the Roche lobes increase anddecrease as a function of the orbital phase. At periastron, thesecondary star fills its Roche lobe. The distance to the star has beenre-determined as d = 1.3 ± 0.2 kpc and a color excess ofE(B-V)=0.155~±~0.007 has been derived. This implies an absolute Bmagnitude of -0.6 for the primary star and -0.7 for the B7 star. Wesuggest that the discrete absorption components (DACs) observed in theultraviolet with a periodicity similar to the orbital period may beinduced by periastron events.Based on observations made at the 1.5 m ESO telescope at La Silla, Chile, and at Laboratório Nacional de Astrofísica/CNPq, Brazil.Tables 2-5 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/444/895
| OB Stellar Associations in Crux. II. Analysis and Discussion
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996AJ....111..306T&db_key=AST
| OB Stellar Associations in Crux. I. Observations With the Glazar Space Telescope
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996AJ....111..299T&db_key=AST
| SAO stars with infrared excess in the IRAS Point Source Catalog
We have undertaken a search for SAO stars with infrared excess in theIRAS Point Source Catalog. In contrast to previous searches, the entireIRAS (12)-(25)-(60) color-color diagram was used. This selection yieldeda sample of 462 stars, of which a significant number are stars withcircumstellar material. The stars selected can be identified aspre-main-sequence stars, Be stars, protoplanetary systems, post-AGBstars, etc. A number of objects are (visual) binary stars.Characteristic temperatures and IR excesses are calculated and theirrelations to spectral type are investigated.
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Osservazione e dati astrometrici
| Costellazione: | Croce del Sud |
| Ascensione retta: | 12h01m23.65s |
| Declinazione: | -62°36'35.5" |
| Magnitudine apparente: | 8.481 |
| Distanza: | 628.931 parsec |
| Moto proprio RA: | -21 |
| Moto proprio Dec: | 2.7 |
| B-T magnitude: | 8.55 |
| V-T magnitude: | 8.487 |
Cataloghi e designazioni:
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