[en] Light variability was observed over time intervals of months to years in the stars HD 55540, HD 71066, HD 94660, and HD 187474. The significance of these results is discussed in terms of the frequency of chemically peculiar CP2 stars showing (light) variability with periods longer than one month. This frequency, relative to the whole CP2 population, must lie somewhere between 4 and 16 percent. Observations, properly distributed in time, of a small subgroup of CP2 stars will be sufficient to obtain an accurate ratio of the number of LP-CP2 stars to the total number of CP2 stars. These observations, when continued until the periodicity is detected, could contribute also to the discussion whether these long periods should be identified with the rotation period.
Manfroid, Jean ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Département d'astrophys., géophysique et océanographie (AGO)
Renson, Pierre ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Evol. et stabilité des étoiles et des amas d'étoiles (ESEA)
Schneider, H.; Universitaetssternwarte, Goettingen, West Germany
Catalano, F. A.; Osservatorio Astrofisico, Catania, Italy
Weiss, W. W.; Wien, Universitaet, Vienna, Austria
Floquet, M.; Meudon, Observatoire, Meudon, Hauts-de-Seine, France
Maitzen, H. M.
Language :
English
Title :
The frequency of Ap-stars with long rotation periods