Time-resolved Spectroscopy of the Polar EU Cancri in the Open Cluster Messier 67

Abstract

We present time-resolved spectroscopic and polarimetric observations of the AM Her system EU Cnc. EU Cnc is located near the core of the old open cluster Messier 67; new proper motion measurements indicate that EU Cnc is indeed a member of the star cluster, this system therefore is useful to constrain the formation and evolution of magnetic cataclysmic variables. The spectra exhibit two-component emission features with independent radial velocity variations as well as time-variable cyclotron emission indicating a magnetic field strength of 41 MG. The period of the radial velocity and cyclotron hump variations are consistent with the previously-known photometric period, and the spectroscopic flux variations are consistent in amplitude with previous photometric amplitude measurements. The secondary star is also detected in the spectrum. We also present polarimetric imaging measurements of EU Cnc that show a clear detection of polarization, and the degree of polarization drops below our detection threshold at phases when the cyclotron emission features are fading or not evident. The combined data are all consistent with the interpretation that EU Cnc is a low-state polar in the cluster Messier 67. The mass function of the system gives an estimate of the accretor mass of M_WD >= 0.68 M_sun with M_WD ~ 0.83 M_sun for an average inclination. We are thus able to place a lower limit on the progenitor mass of the accreting WD of >= 1.43 M_sun.

arXiv commentAccepted for publication in the Astronomical Journal. 9 pages, 5 figures, uses emulateapj

References in corpus (31)

• Cosmic-Ray Rejection by Laplacian Edge Detection
• Empirical Color Transformations Between SDSS Photometry and Other Photometric Systems
• A Survey of Star-Forming Galaxies in the z=1.4-2.5 `Redshift Desert': Overview
• Evolutionary Binary Sequences for Low- and Intermediate-Mass X-ray Binaries
• An Improved Spectroscopic Analysis of DA White Dwarfs from the Sloan Digital Sky Survey Data Release 4
• A Comprehensive Spectroscopic Analysis of DB White Dwarfs
• Dynamical Formation of Close Binary Systems in Globular Clusters
• The Initial-Final Mass Relation: Direct Constraints at the Low Mass End
• An Exploration of the Paradigm for the 2-3 Hour Period Gap in Cataclysmic Variables
• Found: The missing blue opacity in atmosphere models of cool hydrogen white dwarfs
• Post-common-envelope binaries from SDSS. XI: The white dwarf mass distributions of CVs and pre-CVs
• Probing The Lower Mass Limit for Supernova Progenitors and the High-Mass End of the Initial-Final Mass Relation from White Dwarfs in the Open Cluster M35 (NGC 2168)
• Cataclysmic Variable Primary Effective Temperatures: Constraints on Binary Angular Momentum Loss
• Deep MMT Transit Survey of the Open Cluster M37 II: Variable Stars
• Chandra Exposes the Core Collapsed Globular Cluster NGC 6397
• Deep 2MASS Photometry of M67 and Calibration of the Main Sequence J-Ks Color Difference as an Age Indicator
• The initial-final mass relationship from white dwarfs in common proper motion pairs
• Star Clusters as Type Ia Supernova Factories
• The Age and Progenitor Mass of Sirius B
• The Optical Polarization of Near-Infrared Selected QSOs
• Planets in Stellar Clusters Extensive Search. II. Discovery of 57 Variables in the Cluster NGC 2158 with Millimagnitude Image Subtraction Photometry
• The end of the white dwarf cooling sequence in M 67
• A Chandra observation of the old open cluster M67
• Planets in Stellar Clusters Extensive Search. IV. A detection of a possible transiting planet candidate in the open cluster NGC 2158
• Variable stars in the open cluster NGC 6791 and its surrounding field
• Further investigation of white dwarfs in the open clusters NGC2287 and NGC3532
• Two Confirmed Cataclysmic Variables in the Old Stellar Cluster NGC 6791
• Long-term variability survey of the old open cluster NGC 6791
• An Unexpected Discovery in the Rich Open Cluster NGC 6819 Using XMM-Newton
• The first search for variable stars in the open cluster NGC 6253 and its surrounding field
• VV Pup in a low state: secondary-star irradiation or stellar activity?

Cited by in corpus (8)

• Magnetic White Dwarfs
• Cataclysmic Variables from the Catalina Real-time Transient Survey
• One thousand cataclysmic variables from the Catalina Real-time Transient Survey
• Identification of twenty-three accreting binaries in the Galactic Bulge Survey
• Ensemble Properties of the White Dwarf Population of the Old, Solar Metallicity Open Star Cluster Messier 67
• Bayesian Hierarchical Modelling of Initial-Final Mass Relations Across Star Clusters
• The Kepler and Hale observations of V523 Lyr
• The Intriguing Polar EU Cancri in the Eyes of Kepler K2