CAOSP abstracts, Volume: 27, No.: 3, year: 1998
- Author(s): MAITZEN, M.M.; RODE, M.; PAUNZEN, E.
- Journal: Contributions of the Astronomical Observatory Skalnate Pleso,
vol. 27, no. 3, p. 213-217.
- Date: 04/1998
- Title: CP2 stars in clusters: deep Delta a-photometry
- Keyword(s): STARS: CHEMICALLY PECULIAR, PHOTOMETRY
- Pages: 213 -- 217
The search for chemically peculiar (CP) stars in open clusters using
photoelectric photometry sampling the presence of the characteristic
flux depression feature at 5200 Angstroms via the Delta a system.
has so far delivered data for objects usually no more distant than 1000 pc
from the Sun. If one intends to study the presence of CP stars at larger
distances from the Sun, classical photometry has to be replaced by
CCD photometry. For the first time, our investigation presents the results
of CCD-photometry in the Delta a-system for a rich open cluster which is at
a distance clearly beyond hitherto studied objects, Melotte 105
(2 kpc, log age = 8.5). Comparison with published uvby-photometry yields
the calibration of the colour index g(1)-y of our system, which is
necessary for deriving the peculiarity index Delta a. For this we achieve
an average accuracy of 0.007 mag. Six objects with only marginally peculiar
Delta a values were found, but spectroscopic and additional photometric
evidence is needed to substantiate their peculiarity.
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