CCD photometric search for peculiar stars in open clusters. VIII. King 21, NGC 3293, NGC 5999, NGC 6802, NGC 6830, Ruprecht 44, Ruprecht 115, and Ruprecht 120

Abstract

We continue our survey for magnetic chemically peculiar (CP2) stars in galactic open clusters to shed more light on their origin and evolution. To study the group of CP2 stars, it is essential to find these objects in different galactic environments and at a wide range of evolutionary stages. The knowledge of open clusters ages and metallicities can help to find a correlation of these parameters with the (non-)presence of peculiarities which has to be taken into account in stellar evolution models. The intermediate band Delta a photometric system samples the depth of the 5200A flux depression by comparing the flux at the center with the adjacent regions with bandwidths of 110A to 230A. It is capable to detect magnetic CP2 and CP4 stars with high efficiency, but also the groups of (metal-weak) lambda Bootis, as well as classical Be/shell stars can be successfully investigated. In addition, it allows to determine the age, reddening and distance modulus with an appropriate accuracy by fitting isochrones. From the 1677 observed members of the eight open clusters, twenty five CP2 and one Ae stars were identified. Further nineteen deviating stars are designated as questionable due to several reasons. The estimated age, reddening and distance for the programme clusters were compared with published vales of the literature and discussed in this context. The current paper shows that CP2 stars are present continuously in very young (7Myr) to intermediate age (500Myr) open clusters at distances larger than 2kpc from the Sun.

10 pages, 3 figures, A&A accepted

References in corpus (3)

• Searching for links between magnetic fields and stellar evolution. I. A survey of magnetic fields in open cluster A- and B-type stars with FORS1
• On the current status of open-cluster parameters
• CCD photometric search for peculiar stars in open clusters. VII. Berkeley 11, Berkeley 94, Haffner 15, Lynga 1, NGC 6031, NGC 6405, NGC 6834 and Ruprecht 130

Cited by in corpus (12)

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• Three new Galactic star clusters discovered in the field of the open cluster NGC 5999 with Gaia DR2
• Radial Velocities of Three Poorly Studied Clusters and the Kinematics of Open Clusters
• CCD $UBV(RI{)}_C$ Photometry of Twenty Open Clusters
• Photometric study of the young open clusters IC 1442, King 21, and Trumpler 7
• The Gaia-ESO survey: A spectroscopic study of the young open cluster NGC 3293
• The detection of magnetic chemically peculiar stars using Gaia BP/RP spectra
• An Investigation of Four Chemically Peculiar Stars with Photometric Periods below 12 Hours
• The first Delta a observations of three globular clusters
• A search for peculiar stars in the open cluster Hogg 16
• Analytical Studies of NGC 2571, NGC 6802, Koposov 53 and Be 89
• Chemically peculiar stars on the pre-main sequence