000002293 001__ 2293
000002293 005__ 20160706142003.0
000002293 0247_ $$2DOI$$a10.1051/0004-6361/201014262
000002293 037__ $$aASTROimport-450
000002293 100__ $$aPedicelli, S.
000002293 245__ $$aNew Baade-Wesselink distances and radii for four metal-rich Galactic Cepheids
000002293 260__ $$c2010
000002293 520__ $$aAims: We provide accurate estimates of distances, radii, and iron abundances of four metal-rich Cepheids, namely V340 Ara, UZ Sct, AV Sgr, and VY Sgr. The main aim of this investigation is to constrain their pulsation properties and their location across the Galactic inner disk. Methods: We adopted new accurate NIR (J,H,K) light curves and new radial velocity measurements for the target Cepheids to determinate their distances and radii using the Baade-Wesselink technique. In particular, we adopted the most recent calibrations of both the IR surface brightness relation and the projection factor. We also provide accurate measurements of the iron abundance of the target Cepheids.  Results: Current distance estimates agree to within one s with similar distances based on either empirical or theoretical NIR Period-Luminosity (P-L) relations. However, the uncertainties in the Baade-Wesselink distances are on average a factor of 3-4 smaller than errors affecting other distance determinations. Mean Baade-Wesselink radii also agree at the one s level with Cepheid radii based either on empirical or theoretical Period-Radius relations. Iron abundances are, within one s, similar to those determined by Andrievsky and collaborators, thus confirming that the target Cepheids are super metal-rich. We also found that the luminosity amplitudes of classical Cepheids, at odds with RR Lyrae stars, do not exhibit a clear correlation with their metal content. This circumstantial evidence appears to be caused by the Hertzsprung progression and the dependence of the topology of the instability strip on metallicity, evolutionary effects, and binaries. Based on observations made with MPG/ESO 2.2 m telescope at La Silla Observatory under proposal IDs: 75.D-0676, 60.A-9120 and multi-epoch, multi-band NIR data at SAAO.
000002293 700__ $$aLemasle, B.
000002293 700__ $$aGroenewegen, M.
000002293 700__ $$aRomaniello, M.
000002293 700__ $$aBono, G.
000002293 700__ $$aLaney, C. D.
000002293 700__ $$aFrançois, P.
000002293 700__ $$aBuonanno, R.
000002293 700__ $$aCaputo, F.
000002293 700__ $$aLub, J.
000002293 700__ $$aPel, J. W.
000002293 700__ $$aPrimas, F.
000002293 700__ $$aPritchard, J.
000002293 773__ $$cA11$$pAstronomy and Astrophysics$$v518$$y2010
000002293 85642 $$ahttp://esoads.eso.org/abs/2010A%26A...518A..11P
000002293 905__ $$apublished in
000002293 980__ $$aREFERD