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Multiperiodicity in the atypical delta SCT star AN Lyn
New uvby data collected of AN Lyn together with the reanalysis of olddata establish that this star is a multiperiodic pulsator. Threeindependent frequencies (nu _1=10.1756, nu _2=18.1309 and nu _3=9.5598cd(-1) ) and some interactions between them are found to be present inthe light curve. Changes in amplitude with a large time scale areconfirmed for the main frequency. Moreover, changes in amplitude arealso present for the secondary frequencies, especially for nu _3. Aftersubtraction of the secondary frequencies from the light curves, theclassical O-C method has been used to analyse the behaviour of the mainperiod. A comparison is made between AN Lyn and the other two knowndelta Sct stars with atypical light curves, i.e., V1719 Cyg and V798Cyg. New uvby data have been also collected for V1719 Cyg and the O-Cmethod has been used to analyse the behaviour of the main period. It isfound that the main pulsation of this star can be well described bymeans of a linear ephemeris with a period of P=0.(d) 26729700 over thelast eighteen years. Finally, analysis of the different data setsavailable in the literature do not reveal significative changes in theamplitude of the main frequency of V1719 Cyg. Table 5 will be accessibleonly in electronic form at the CDS
| 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.
| Kinematics of Sandage-Fouts stars in three cardinal directions
V and (B - V) for 429, 442, and 427 stars are observed in the directionsof the anticenter, Cygnus, and the NGP, respectively, and DDO colors forthose stars G0 and later. The samples observed are ones for whichSandage and Fouts (1987) have published radial velocities. W, V, and Wcomponents of space velocity are derived from DDO distances withavailable proper motions. A clear correlation was found to exist betweenthe velocity dispersions and Fe/H with the dispersions decreasing asFe/H increases to about + 0.00, where V then becomes significantlynegative. The 'thick disk' component is clearly recognized, with sigma(W) approximately equal to 36 km/sec. In the 'old thin disk' and the'young thin disk', 43 percent and 42 percent of the stars have negativeV values, respectively.
| U, V, W velocity components for the old disk using radial velocities of 1295 stars in the three cardinal Galactic directions
New radial velocities are presented for 1295 stars chosen at random nearthe three cardinal Galactic directions of l = 180 deg, b = 0; l = 90deg, b = 0 deg; and b = 90 deg, giving the distribution in U, V, and W,respectively, from the radial velocities alone. The measurements weremade with the coude spectrograph of the Mount Wilson 100 in. Hookerreflector. The purpose of the program is to set limits on the densitynormalization in the solar neighborhood of the old thin disk, the oldthick disk, and the halo. Many more high-velocity stars are present inthe unbiased sample than expected from previous estimates of thenormalization. The data suggest the density ratios in the solarneighborhood to be about 90 percent, 10 percent, and about 0.5 percentfor the thin disk, thick disk, and halo populations, respectively.
| UBV photometry of stars whose positions are accurately known. II
The present report on the UBV observations of stars with favorableastrometric history gives attention to stars of the BD zones lyingbetween 50 and 54 deg. These observations and their reductions wereperformed from August 1983 to August 1984, as described by Oja (1984).Results are presented as tables for both the standard stars and theprogram stars. Comparisons are conducted between the present Vmagnitudes and those of the NPZT (1982) and AGK3R (1978) catalogs.
| Meridian observations made with the Carlsberg Automatic Meridian Circle at Brorfelde (Copenhagen University Observatory) 1981-1982
The 7-inch transit circle instrument with which the present position andmagnitude catalog for 1577 stars with visual magnitudes greater than11.0 was obtained had been equipped with a photoelectric moving slitmicrometer and a minicomputer to control the entire observationalprocess. Positions are reduced relative to the FK4 system for each nightover the whole meridian rather than the usual narrow zones. Thepositions of the FK4 stars used in the least squares solution are alsogiven in the catalog.
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Membre dels grups següents:
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Dades d'Observació i Astrometria
| Constel·lació: | Cygnus |
| Ascensió Recta: | 21h05m14.20s |
| Declinació: | +51°09'03.8" |
| Magnitud Aparent: | 8.811 |
| Distancia: | 114.416 parsecs |
| Moviment propi RA: | 57.1 |
| Moviment propi Dec: | 28.4 |
| B-T magnitude: | 9.361 |
| V-T magnitude: | 8.857 |
Catàlegs i designacions:
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