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J/ApJ/586/1356     White dwarfs with cool companions          (Wachter+, 2003)

Cool companions to white dwarfs from the Two Micron All-Sky Survey Second Incremental Data Release. Wachter S., Hoard D.W., Hansen K.H., Wilcox R.E., Taylor H.M., Finkelstein S.L. <Astrophys. J. 586, 1356 (2003)> =2003ApJ...586.1356W
ADC_Keywords: Stars, double and multiple ; Infrared sources ; Photometry, infrared Keywords: binaries: general - infrared: stars - stars: fundamental parameters - surveys - white dwarfs Abstract: We present near-infrared (IR) magnitudes for all white dwarfs (selected from the catalog of McCook & Sion, 1999, See Cat. III/235) contained in the Two Micron All-Sky Survey second incremental data release (2MASS 2IDR, Cat. II/241). We show that the near-IR color-color diagram is an effective means of identifying candidate binary stars containing a WD and a low-mass, main-sequence star. The loci of single WDs and WD+red dwarf binaries occupy distinct regions of the near-IR color-color diagram. We recovered all known unresolved WD+red dwarf binaries located in the 2IDR sky coverage and also identified as many new candidate binaries (47 new candidates out of 95 total). Using observational near-IR data for WDs and M-L dwarfs, we have compared a sample of simulated WD+red dwarf binaries with our 2MASS data. The colors of the simulated binaries are dominated by the low-mass companion through the late M to early L spectral types. As the spectral type of the companion becomes progressively later, however, the colors of unresolved binaries become progressively bluer. Binaries containing the lowest mass companions will be difficult to distinguish from single WDs solely on the basis of their near-IR colors. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 68 95 White dwarf+low-mass, main-sequence star binary candidates table2.dat 68 15 Tentative WD+low-mass, main-sequence star binary candidates
See also: II/241 : 2MASS Catalog Intermediate Data Release (IPAC/UMass, 2000) III/235 : Spectroscopically Identified White Dwarfs (McCook+, 2003) Byte-by-byte Description of file: table1.dat table2.dat
Bytes Format Units Label Explanations
1- 10 A10 --- WD WD designation (based on 1950 positions) 12- 20 A9 --- Ref Reference for binarity (1) 22 A1 --- n_Ref [a-j] Note on Ref (2) 24- 29 F6.3 mag Jmag J magnitude 32- 36 F5.3 mag e_Jmag rms uncertainty on Jmag 40- 45 F6.3 mag Hmag H magnitude 48- 52 F5.3 mag e_Hmag rms uncertainty on Hmag 56- 61 F6.3 mag Ksmag Ks magnitude 64- 68 F5.3 mag e_Ksmag rms uncertainty on Ksmag
Note (1): References as follows: 1 = Schultz, Zuckerman, & Becklin, 1996ApJ...460..402S 2 = Greenstein, 1986AJ.....92..867G 3 = Schultz et al., 1993BAAS...25..824S 4 = Gizis & Reid, 1997PASP..109..849G, Cat. J/PASP/109/849 5 = Fulbright & Liebert 1993 6 = Orosz et al., 1999AJ....117.1598O 7 = Koester et al., 2001A&A...378..556K, Cat. J/A+AS/378/556 8 = Stepanian et al., 2001AJ....122.3361S 9 = Zuckerman & Becklin, 1992ApJ...386..260Z 10 = Finley, Koester & Basri 1997 11 = Reid et al., 1988AJ.....96..275R 12 = Marsh & Duck, 1996MNRAS.278..565M MS99 = McCook & Sion, 1999ApJS..121....1M, See Cat. III/235 Note (2): Individual notes as follows: a = WD 0023+388 is a known triple system composed of a close WD+red dwarf pair with a wide red dwarf companion (Reid, 1988AJ.....96..275R) b = WD 0034-211 is classified as a close double-degenerate binary in MS99 (See Cat. III/235). Bragaglia et al. (1990ApJ...365L..13B) reclassified it as a WD+red dwarf binary, which is supported by its 2MASS colors. c = WD 0102+210.2 is classified as one component of a wide double-degenerate binary (Sion et al., 1991AJ....101.1476S), but our 2MASS colors suggest that it may be a close WD+red dwarf binary also. d = WD 0205+133 may be an sdOB+red dwarf binary instead of a WD+red dwarf binary (Allard et al., 1994AJ....107.1565A). e = This object is classified as the WD component of a wide (resolved) WD+red dwarf binary, but our 2MASS colors suggest that the WD may also be a close WD+red dwarf binary. f = The binary separation of WD 0628-020 (4) is near the 2MASS resolution limit. There is only one entry in the 2IDR point source catalog, but these magnitudes may be for the red dwarf component only. g = The companion of WD 1517+502 is a dwarf carbon star (Liebert et al., 1994ApJ...421..733L). h = WD 1610+383 is barely resolved on the DSS images as a common proper motion pair with red and blue components at a separation of 4. Blinking of the DSS and 2MASS images suggests that only the red component is detected by 2MASS. Its near-IR colors are consistent with an early M spectral type. i = This object is classified as the WD component of a wide (resolved) binary, but our 2MASS colors suggest that the WD may also be a close WD+red dwarf binary. j = MS99 (See Cat. III/235) note that WD 1247+550 is "possibly the coolest known degenerate star."-------------------------------------------------------------------------------- History:
History: From electronic version of the journal
(End) James Marcout, Patricia Bauer [CDS] 22-May-2003
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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