Anchors for the Cosmic Distance Scale: the Cepheids U Sgr, CF Cas and
  CEab Cas

Balam, D.; Beletsky, Y.; Berdnikov, L.; Bidin, C. Moni; Bonatto, C.; Borissova, J.; Carraro, G.; Gallo, L.; Gieren, W.; Kovtyukh, V.; Lane, D.; Majaess, D.; Moyano, M.; Turner, D.

research

Anchors for the Cosmic Distance Scale: the Cepheids U Sgr, CF Cas and CEab Cas

Authors: D. Balam
Y. Beletsky
L. Berdnikov
C. Moni Bidin
C. Bonatto
J. Borissova
G. Carraro
L. Gallo
W. Gieren
V. Kovtyukh
D. Lane
D. Majaess
M. Moyano
D. Turner
Publication date: 1 January 2013
Publisher: 'EDP Sciences'
Doi

Abstract

New and existing X-ray, UBVJHKsW(1-4), and spectroscopic observations were analyzed to constrain fundamental parameters for M25, NGC 7790, and dust along their sight-lines. The star clusters are of particular importance given they host the classical Cepheids U Sgr, CF Cas, and the visual binary Cepheids CEa and CEb Cas. Precise results from the multiband analysis, in tandem with a comprehensive determination of the Cepheids' period evolution (dP/dt) from ~140 years of observations, helped resolve concerns raised regarding the clusters and their key Cepheid constituents. Specifically, distances derived for members of M25 and NGC 7790 are 630+-25 pc and 3.40+-0.15 kpc, respectively.Comment: To appear in Astronomy and Astrophysic