| Résumé | The likely membership of the planetary nebula Abell 8 (PN G167.0-00.9) in the open cluster Bica 6 is confirmed by CCD spectra, UBV (RI) C photometry, and radial velocities for luminous cluster stars. The reddening, estimated distance, and radial velocity of the planetary nebula agree with parameters derived for Bica 6 of E B-V (mean) 1/4 0:42, d 1/4 1:60 ± 0:11 kpc, and V R 1/4 57 ± 1 km s -1, with a cluster age of 10 9 yr, a diagnostic blue hook, and a few blue stragglers, including a peculiar B1 Vnn star (HDE 277593) that may be a post-AGB star. The results identify Bica 6 as a potential calibrator of the planetary nebula distance scale. The central star of the planetary nebula has a reddening of E B-V 1/4 0:49 ± 0:02, with a possible circumnebular excess, and an estimated luminosity of M V = +7.44 ± 0.16. It is also an optical double in 2MASS images, with a likely progenitor according to evolutionary considerations being a late B-type dwarf of ~2:3 M.⊙. © 2011. The Astronomical Society of the Pacific. All rights reserved. |
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