Astron. Astrophys. Suppl. Ser. 147, 99-109
C. Bayer1 - H.M. Maitzen1 - E. Paunzen1,2 - M. Rode-Paunzen1 - M. Sperl1
Send offprint request: E. Paunzen,e-mail: Ernst.Paunzen@univie.ac.at
1 - Institut für Astronomie der Universität Wien, Türkenschanzstr. 17, A-1180 Wien, Austria
2 - Zentraler Informatikdienst der Universität Wien, Universitätsstr. 7, A-1010 Wien, Austria
Received April 3; accepted August 25, 2000
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. We have therefore initialized in 1995 a new survey in open clusters and the Large Magellanic Cloud using the CCD technology.
As a first step, we have presented new -photometry of 22 CP2 stars in the galactic field to prove the capability of CCD photometry for our aim (Maitzen et al. 1997).
In the first paper of a new series devoted to CCD photometry, we present data on NGC 2169 (13 stars investigated), Melotte 105 (114 stars), and NGC 6250 (48 stars). NGC 2169 was used to test our results with those of classical photometry which yields excellent agreement.
For NGC 6250 we find two new definite CP2 (according to the definition by Preston 1974) stars ( and 0.026 mag) and two Bootis candidates. Twelve objects with only marginally peculiar -values for Melotte 105 were detected. Additional spectroscopic and photometric evidence is needed to substantiate their peculiarity.
Key words: stars: chemically peculiar -- stars: early-type -- techniques: photometric -- open clusters and associations: general
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