Double white dwarfs

Name Period Pdot d M2 q M1 i Mv V RA DEC l b
[s] [s/s] [pc] Msun Msun [deg] [h:m:s] [d:m:s] [deg] [deg]
SDSS J0651+2844 765.4+/-7.9 ? ~1000 0.50 0.5 0.25 86.9+1.6-1 ? g=19.1 06 51 33.338 +28 44 23.37 186.93 12.69
SDSS J0935+4411 1188+/-44 ? ~660 >0.14 ? 0.32 ? ? g=17.7 09 35 XX +44 11 YY
SDSS J0106-1000 2346+/-2 ? ~2400 0.43 0.4 0.17 67+/-13 ? g=19.8 01 06 57.39 -10 00 03.3 135.72 -72.47
SDSS J1630+4233 2390+/-4 ? ~830 >0.52 ? 0.31 ? ? g= 16 30 XX +42 33 YY
SDSS J1053+5200 3680+/-10 ? ~1100 >0.26 ? 0.20 ? ? g=18.87 10 53 53.89 +52 00 31.0 156.40 +56.79
SDSS J0923+3028 3884 ? 270 >0.34 ? 0.23 ? ? g= 09 23 45.59 +30 28 05.0 195.82 44.78
SDSS J1436+5010 3957 +/-10 ? ~800 >0.46 ? 0.24 ? ? g=18.16 14 36 33.29 +50 10 26.8 089.01 +59.46
WD 0957-666 5269.81080+/-0.00007 ? 135 +/- 20 0.32 +/- 0.03 1.15 +/- 0.10 0.37 +/- 0.02 50 – 86 8.94 14.60 09 58 54.96 –66 53 10.2 287.14 -9.46
SDSS J0755+4906 5445 ? 2620 >0.81 ? 0.17 ? ? 07 55 52.40 +49 06 27.9 169.76 30.42
SDSS J0849+0445 6800 ? 930 >0.64 ? 0.17 ? ? 08 49 10.13 +04 45 28.7 222.70 28.27
SDSS J0022-1014 6902 ? 790 >0.19 ? 0.33 ? ? 00 22 07.65 -10 14 23.5 99.30 -71.75
SDSS J2119-0018 7497 ? 2500 >0.75 ? 0.17 ? ? 21 19 21.96 -00 18 25.8 51.58 -32.54
SDSS J1234-0228 7900 ? 780 >0.09 ? 0.23 ? ? 12 34 10.36 -02 28 02.8 294.25 60.11
WD 1101+364 12503 +/- 5 ? 97 +/- 15 0.36 0.87 +/- 0.03 0.31 25 9.55 14.49 11 04 32.61 +36 10 49.5 184.48 +65.62
WD 1704+4807BC 12511 +/- 2 ? 0.56 +/- 0.07 0.70 +/- 0.03 0.39 +/- 0.05 61 14.5 17 05 30.1 +48 03 17 74.25 +37.19

For low mass SDSS systems see Kilic et al. 2011a still need to add more information (GN)

SDSS J0651+2844

12 minute system found by Kilic & co Brown et al. 2011

SDSS J0935+4411

20 min system, Kilic & co Kilic et al. 2014

SDSS J0106-1000

SDSS J1053+5200

Paper now out Kilic et al. 2010

Reported by Badenes in KITP conference, 2009, http://online.kitp.ucsb.edu/online/sdeath_c09/ as a short period double white dwarf. It has a radial velocity amplitude of 310 +/- 14 km/s. They observed the star as it was one of the targets discussed by Kilic et al (2007) for being a very low mass white dwarf (0.19 Msun). Such stars are very likely to be binary as this one indeed is (TRM). The mass of the unseen (secondary) star is a lower limit calculated from the radial velocity amplitude and the 0.19 Msun mass for the primary. Kilic et al (2007) lists a temperature of 15,900K, which combined with the mass of the brighter object should give a distance.

SDSS J1630+4233

SDSS J1436+5010

Paper now out Kilic et al. 2010

Second system reported by Badenes at KITP conference, 2009, http://online.kitp.ucsb.edu/online/sdeath_c09/ (see SDSS J1053+5200). This is also another star from Kilic et al (2007). The radial velocity semi-amplitude K = 388 +/- 21 km/s, which leads to the lower limit on the mass of the secondary star assuming the quoted mass for the primary star. Kilic et al (2007) list a temperature of 18,400 K cf 17,000 K from Eisenstein et al (2006) where this star was first identified as a low mass white dwarf.

WD 0957-666

Period from Moran et al (1997); distance from Bragaglia et al (1995). Uncertainty in the distance is a bit of a guess; formal uncertainties are lower, but things are never quite as good as formal uncertainties suggest. Nevertheless, this distance (which is based upon the apparent magnitude versus model atmosphere fits (with a 20% correction for the light of the companion which I have used to raise the absolute magnitude of the system by 0.2 mags), and should be pretty good. (TRM)

Mass ratio q = M1/M2 (brighter over fainter). This is a double-lined system and so the mass ratio is well determined. (TRM)

The masses are from Moran et al (1997). The inclination comes from taking a 2-sigma lower limit on sin i from Moran et al (1997) together with an absence of observed eclipses from Hoard & Wachter (2002) (TRM).

WD 1101+364

Marsh (1995) discovered this star to be a binary. It is a double-lined system (TRM). The absolute magnitude has been corrected up by 0.75 mags from a straight model atmosphere fit because the system is a very equal double (TRM). Masses and inclination are not well constrained; mass ratio is OK (TRM). As usual for the double white dwarfs, the mass ratio = M(bright)/M(faint) (TRM).

WD 1704+4807BC

Maxted et al (2000) discovered that this star was a close binary. It is part of a triple system with another white dwarf and hence the 'BC' designation (TRM). Mass ratio is ratio of masses of the bright over the faint component (TRM).

 
verification_binaries/double_white_dwarfs.txt · Last modified: 2016/11/18 21:27 (external edit)
 
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