SCYON Abstract

Received on May 31 2012

Anchoring the Distance Scale via X-ray/IR Data for Cepheid Clusters: SU Cas

AuthorsD. Majaess (1), D.G. Turner (1), L. Gallo (1), W. Gieren (2), C. Bonatto (4), D.J. Lane (1), D. Balam (3), and L. Berdnikov (5,6)
Affiliation (1) Saint Mary's University, Halifax, Nova Scotia, Canada
(2) Universidad de Concepcion, Concepcion, Chile
(3) Dominion Astrophysical Observatory, Victoria, BC, Canada
(4) Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
(5) Moscow M V Lomonosov State University, Sternberg Astronomical Institute, Moscow 119992, Russia
(6) Isaac Newton Institute of Chile, Moscow Branch, Universitetskij Pr. 13, Moscow 119992, Russia.
Accepted byAstrophysical Journal
Contactdmajaess@cygnus.smu.ca
URLhttp://adsabs.harvard.edu/abs/2012arXiv1205.0016M
Links Alessi 95

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 H0.