Anchoring the Distance Scale via X-ray/IR Data for Cepheid Clusters: SU Cas
Abstract
New X-ray (XMM-Newton) and JHKs (OMM) observations for members of the star cluster Alessi 95, which Turner et al.(2012) discovered hosts the classical Cepheid SU Cas, were used in tandem with UCAC3 (proper motion) and 2MASS observations to determine precise cluster parameters: E(J-H)=0.08+-0.02 and d=405+-15 pc. The ensuing consensus among cluster, pulsation, IUE, and trigonometric distances (d=414+-5(se)+-10(sd) pc) places SU Cas in a select group of nearby fundamental Cepheid calibrators (Delta Cep, Zeta Gem). High-resolution X-ray observations may be employed to expand that sample as the data proved pertinent for identifying numerous stars associated with SU Cas. Acquiring X-ray observations of additional fields may foster efforts to refine Cepheid calibrations used to constrain H_0.
Cite
@article{arxiv.1205.0016,
title = {Anchoring the Distance Scale via X-ray/IR Data for Cepheid Clusters: SU Cas},
author = {Daniel J. Majaess and David G. Turner and Luigi C. Gallo and Wolfgang P. Gieren and Charles Bonatto and David D. Balam and David J. Lane and Leonid N. Berdnikov},
journal= {arXiv preprint arXiv:1205.0016},
year = {2015}
}
Comments
To appear in ApJ