Confirmation among visual multiples of an increase of AP stars with age.
Abstract
Open clusters with ages below certain threshold values contain no Ap stars and those with greater ages contain numbers of Ap stars that apparently increase with age. But in view of the few young clusters studied, the data could also be interpreted in terms of random differences in the frequencies of Ap stars between individual clusters, rather than an age effect. Data on 77 field visual multiple systems (that originated from many different clusters and associations) in which the primaries are O5-A1 stars and the secondaries occur in the absolute magnitude range of the Ap stars were, therefore, obtained. Again spectral classification shows no Ap stars in systems with ages not greater than 1,000,000 yr and a steady increase in Ap stars thereafter. The numerical agreement with the cluster data is good, confirming that the cluster data are exhibiting a real age effect.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1983
- DOI:
- 10.1086/161276
- Bibcode:
- 1983ApJ...272..182A
- Keywords:
-
- A Stars;
- Companion Stars;
- Peculiar Stars;
- Star Clusters;
- Star Distribution;
- Stellar Evolution;
- Open Clusters;
- Stellar Magnitude;
- Stellar Spectra;
- Astrophysics