Photoelectric observations of 14 Ap stars.
Abstract
U'B' V' observations of 14 Ap stars have been carried out between July 1963 and July 1964 at Lowell Observatory. The best elements of the light variation for the observed stars are: HD 8441 JD (U' max)=2438327.8+69d.433 E. HD 9996 The observations suggest P = 36d5 RD 11503 Two periods P = 2d6 and P = 1d7982 are compatible with the observations. JD (B' min) = 2438376.6. Superimposed short period variations within 2h3 have been established. RD 18296 JD (V' min)=2438343.85+2d.8842 E. RD 30466 JD (U'B'V' max)=2438466.729+ 1d.3900. F. HD 33254 shows no variations. HD 42616 JD (U' min) = 2438450.7 + 17d0 E. RD 74521 JD (V' min)=2438481.5+4d.2393 E. RD 133029 JD (U' max)=2438544.72+2d.8881 E. RD 145389 JD( )=2438523.2+7d.832E. RD 153882 JD( )=2438580.92+6d.0075E. RD 173650 JD( )=2438284.7+10d.1353E. RD 215038 JD (V' max)=2438350.57+2d.037638 E. RD 219749 Three different periods 0d723, 1d61553 and 2d6 are compatible with the observations. JD (U' max) =2438284.67. It is obvious that the periods derived still may be erroneous and in general more observations are needed to establish the intrinsic periods. Semiperiodical fluctuations in brightness in a short time scale have been found in RD 11503, RD 74521, RD 153882 and RD 173650. The star RD 153882 has indications of a secular change in the brightness. The reality of the short and long time variations in the radiation output of Ap stars are discussed. Key words: magnetic stars - Ap stars - variable stars
- Publication:
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Astronomy and Astrophysics Supplement Series
- Pub Date:
- January 1978
- Bibcode:
- 1978A&AS...31...83R
- Keywords:
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- Peculiar A Stars:Photometry