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HD 22240


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Frequency spectrum of the rapidly-oscillating mass-accreting component of the Algol-type system AS Eri
The first multisite photometric campaign devoted to the rapidlyoscillating mass-accreting (primary) component of the Algol-typeeclipsing binary system AS Eri has confirmed the presence of rapidpulsations with frequency 59.03116 d-1, and revealed thesecond and third oscillation modes with frequencies 62.5631d-1 and 61.6743 d-1, respectively. These modes arerelated to the 5-6 overtone oscillations and are among the shortestperiods excited in non-magnetic MS A-F stars. The nearly equator-onvisibility of eclipsing binaries help to narrow the range of possiblemode identifications for the detectable modes as radial or(l,m)=(1,±1), (l,m)=(2,±2) and (l,m)=(2,±0). Wechecked the high-order pulsation-to-orbital synchronization (POS) usingthe trial mode identification and the Doppler effect correction forfrequencies of non-radial pulsation. We found that (l,m,n)=(1,1,5) or(2,2,5) and (l,m,n)=(2,-2,6) identifications for f1 andf2 modes respectively satisfied the high-order POS. Thesemode identifications are in agreement with the range of modes visible indisk integrated light of an equator-on visible pulsating component.The wavelength distribution of pulsation amplitudes in AS Eri is largestin the Strömgren u filter and decreases toward longer wavelengths.We place AS Eri and other known mass-accreting pulsating components ofAlgols on HR-diagram. They are located inside the instability strip onthe Main Sequence. We also discuss the peculiar evolutionary status ofprimary components in Algols and stress that they are not normal δScuti stars, but form a separate group of pulsators. Finally, we discussproximity and eclipse effects, and have simulated the effect of primaryminimum data gaps that may produce the 1/Porb alias sidelobesin DFT analysis of eclipsing binary data. Aliases from gaps in primaryminimum observations seem to be the principal limitation on spectralwindow functions in asteroseismic studies of eclipsing binaries.

Discovery of Rapid Pulsations in the A3 V Component of the Eclipsing Binary System AS Eridani
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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.

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Osservazione e dati astrometrici

Costellazione:Eridano
Ascensione retta:03h34m53.93s
Declinazione:-03°24'43.1"
Magnitudine apparente:7.517
Distanza:164.745 parsec
Moto proprio RA:35.6
Moto proprio Dec:-20.1
B-T magnitude:7.756
V-T magnitude:7.537

Cataloghi e designazioni:
Nomi esatti   (Edit)
HD 1989HD 22240
TYCHO-2 2000TYC 4719-252-1
USNO-A2.0USNO-A2 0825-00812390
HIPHIP 16699

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