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Fundamental parameters of Be stars located in the seismology fields of COROT
In preparation for the COROT space mission, we determined thefundamental parameters (spectral type, temperature, gravity, V sin i) ofthe Be stars observable by COROT in its seismology fields (64 Be stars).We applied a careful and detailed modeling of the stellar spectra,taking into account the veiling caused by the envelope, as well as thegravitational darkening and stellar flattening due to rapid rotation.Evolutionary tracks for fast rotators were used to derive stellar massesand ages. The derived parameters will be used to select Be stars assecondary targets (i.e. observed for 5 consecutive months) and short-runtargets of the COROT mission. Furthermore, we note that the main part ofour stellar sample falls in the second half of the main sequence lifetime, and that in most cases the luminosity class of Be stars isinaccurate in characterizing their evolutionary status.
| The Identification of New Be Stars in GAUDI
The Ground-based Asteroseismology Uniform Database Interface (GAUDI) isthe result of the preparatory work performed for the COROT satellite. Inthe data available in GAUDI we discovered 17 B-type stars that showemission in their Balmer lines and were not known to display suchemission before, including at least 16 nonsupergiant ones. We thusreclassify those stars as Be stars. These 17 new Be stars increase thenumber of Be stars in the field of view of COROT by ~25%, which isimportant for the target selection of the mission. Moreover, ~70% of thediscovered Be stars are of late subtypes. Be stars have been mostlyfound among early subtypes until now, but this could be due to anobservational bias. Finally, one of the discovered stars is either aslowly rotating shell Be star or a Herbig Be star with a low vsini,which makes this star especially interesting.Based on GAUDI, the data archive and access system of the ground-basedasteroseismology programme of the COROT mission. The GAUDI system ismaintained at LAEFF (http://ines.laeff.esa.es/corot/). LAEFF is part ofthe Space Science Division of INTA.
| Two-colour photometry for 9473 components of close Hipparcos double and multiple stars
Using observations obtained with the Tycho instrument of the ESAHipparcos satellite, a two-colour photometry is produced for componentsof more than 7 000 Hipparcos double and multiple stars with angularseparations 0.1 to 2.5 arcsec. We publish 9473 components of 5173systems with separations above 0.3 arcsec. The majority of them did nothave Tycho photometry in the Hipparcos catalogue. The magnitudes arederived in the Tycho B_T and V_T passbands, similar to the Johnsonpassbands. Photometrically resolved components of the binaries withstatistically significant trigonometric parallaxes can be put on an HRdiagram, the majority of them for the first time. Based on observationsmade with the ESA Hipparcos satellite.
| 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.
| Far-ultraviolet stellar photometry - A field in Monoceros
FUV photometry of stars in a field in Monoceros in the wavelength rangefrom 1230 to 1600 A has been carried out using data from anelectrographic Schmidt camera carried on a sounding rocket. Ultravioletmagnitudes were extracted for 602 objects in the field. Fifty-eightpercent were tentatively identified with visible stars using the SIMBADdata base while another 25 percent are blends of objects too closetogether to separate with our resolution. Eleven of the UV objectscoincide with parts of the star clusters NGC 2169, NGC 2244, and NGC2264 in which individual stars cannot be resolved. As in previousstudies, the majority of the identified ultraviolet sources areidentified with early-stars. However, there are a significant number forwhich no such identification was possible, and we suggest that many ofthese are nearby white dwarfs.
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Membre dels grups següents:
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Dades d'Observació i Astrometria
| Constel·lació: | Orion |
| Ascensió Recta: | 06h15m35.70s |
| Declinació: | +07°39'08.1" |
| Magnitud Aparent: | 7.522 |
| Distancia: | 675.676 parsecs |
| Moviment propi RA: | -2.5 |
| Moviment propi Dec: | -1.4 |
| B-T magnitude: | 7.485 |
| V-T magnitude: | 7.519 |
Catàlegs i designacions:
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