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Five New δ Scuti Stars
We present high-resolution spectroscopy and precision photometry of fivenew, relatively bright δ Scuti stars. They were originally chosenas photometric comparison stars in our program of automated,high-precision photometry of solar-type stars and subsequentlyrecognized as new variable stars. We conducted follow-up spectroscopicand photometric observations to determine the properties of the starsand their types of variability. All five of the stars presented herebelong to the most common subgroup of low-amplitude, Population Iδ Scuti variables. One of the stars, HD 10502, is the thirdexample of a δ Scuti variable with composite broad and narrowspectroscopic line profiles suggesting the presence of a circumstellarshell or disk.
| A Transiting ``51 Peg-like'' Planet
Doppler measurements from Keck exhibit a sinusoidal periodicity in thevelocities of the G0 dwarf HD 209458, having a semiamplitude of 81 ms-1 and a period of 3.5239 days, which is indicative of a``51 Peg-like'' planet with a minimum mass (Msini) of 0.62MJup and a semimajor axis of 0.046 AU. Follow-up photometryreveals a drop of 0.017 mag at the predicted time (within the errors) oftransit by the companion based on the velocities. This is the firstextrasolar planet observed to transit its star. The radius of the planetderived from the magnitude of the dimming is 1.42 RJup, whichis consistent with models of irradiated Jupiter-mass planets. Thetransit implies that sini>0.993, leading to a true mass of 0.62MJup for the planet. The resulting mean density of 0.27 gcm-3 implies that the companion is a gas giant.
| Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue.
We give a common version of the two catalogues of Mean Radial Velocitiesby Wilson (1963) and Evans (1978) to which we have added the catalogueof spectroscopic binary systems (Batten et al. 1989). For each star,when possible, we give: 1) an acronym to enter SIMBAD (Set ofIdentifications Measurements and Bibliography for Astronomical Data) ofthe CDS (Centre de Donnees Astronomiques de Strasbourg). 2) the numberHIC of the HIPPARCOS catalogue (Turon 1992). 3) the CCDM number(Catalogue des Composantes des etoiles Doubles et Multiples) byDommanget & Nys (1994). For the cluster stars, a precise study hasbeen done, on the identificator numbers. Numerous remarks point out theproblems we have had to deal with.
| Intermediate band, H-beta, and RI photometry of a large sample of stars unbiased with respect to their motion. I - The F-type stars
Intermediate band and H-beta data from a sample of 1000 stars earlierthan type G2 are presented and discussed relative to the stars'luminosities, metal abundances, and motion. Two groups of stars areconsidered, one within 10 arcsec of the South Galactic Pole and 8.5-8.6mag stars contained in the Moore-Paddock (1950) and Wayman (1960)samples (MP-W). The MP-W stars are mainly old disk population stars withmetal abundances of 4-0.25 solar values. Possible age-abundancedistribution-luminosity connections are explored, as are techniques forseparating old and young disk population objects.
| A new list of 617 radial velocities in four galactic fields
Four stellar fields in the -30 deg galactic latitude have been surveyedfor radial velocities, using a 62 cm objective prism. Exact positions,spectral types, and approximate magnitudes are provided for 617 stars infour different 4 x 4 deg fields. B to F4 stars were found which haveGaussian velocity distributions.
| Radial Velocities, Spectral Types, and Luminosity Classes of 820 Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1950ApJ...112...48M&db_key=AST
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Membre dels grups següents:
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Dades d'Observació i Astrometria
| Constel·lació: | Pegasus |
| Ascensió Recta: | 22h13m38.60s |
| Declinació: | +18°54'09.9" |
| Magnitud Aparent: | 8.011 |
| Distancia: | 186.567 parsecs |
| Moviment propi RA: | -25.4 |
| Moviment propi Dec: | -18.6 |
| B-T magnitude: | 8.288 |
| V-T magnitude: | 8.034 |
Catàlegs i designacions:
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