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Multiperiodicities from the Hipparcos epoch photometry and possible pulsation in early A-type stars
A selection criterion based on the relative strength of the largestpeaks in the amplitude spectra, and an information criterion are used incombination to search for multiperiodicities in Hipparcos epochphotometry. The method is applied to all stars which have beenclassified as variable in the Hipparcos catalogue: periodic, unsolvedand microvariables. Results are assessed critically: although there aremany problems arising from aliasing, there are also a number ofinteresting frequency combinations which deserve further investigation.One such result is the possible occurrence of multiple periods of theorder of a day in a few early A-type stars. The Hipparcos catalogue alsocontains a number of these stars with single periodicities: such starswith no obvious variability classifications are listed, and informationabout their properties (e.g., radial velocity variations) discussed.These stars may constitute a new class of pulsators.
| The 74th Special Name-list of Variable Stars
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| The spectra, magnitudes and colours of O-A type stars in an area of the Milky Way, with the Center alpha = 20h16m, delta = +42 D 30'.
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Osservazione e dati astrometrici
| Costellazione: | Cigno |
| Ascensione retta: | 20h20m39.19s |
| Declinazione: | +43°07'37.2" |
| Magnitudine apparente: | 8.985 |
| Distanza: | 769.231 parsec |
| Moto proprio RA: | -5.9 |
| Moto proprio Dec: | -10.8 |
| B-T magnitude: | 9.331 |
| V-T magnitude: | 9.014 |
Cataloghi e designazioni:
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