Session: |
White Dwarfs: Search, Survey, Study, and Understand? |
Presentation Number: |
103.06 |
Title: |
Meet Your Local White Dwarf Neighbors: A Census of the 20 pc Sample |
Presentation Start: |
1/8/2007 9:20:00 AM |
Presentation End: |
1/8/2007 6:30:00 PM |
Category: |
08. White Dwarfs, Neutron Stars, & Pulsars |
Authors: |
Sean Foran1, E. Sion1, J. Holberg2, G. McCook1
1Villanova University, 2University of Arizona. |
We present an updated census of the white dwarf stars within 20 pc of the sun using the web-based Villanova White Dwarf Catalog (http://www.astronomy.villanova.edu/WDCatalog/). Among the sample of 119 stars within this volume, there are 64 DA (H-rich) stars, 52 non-DA (He-rich) stars, 32 DC (no spectral features) stars, 13 DQ (molecular carbon) stars, 5 DZ (He-rich with Ca II) stars, 1 peculiar DBQA star, and 11 magnetic degenerates of which four are He-rich magnetic DQ stars. We discuss our derived local space density of white dwarfs, estimate the space densities of each spectroscopic subclass, estimate formation rates, the binary fraction, and the space motions of the sample. We discuss the implications of these formation rates for current scenarios of white dwarf progenitorship and spectral evolution.
This work is supported by NSF grant 05-07797. |
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