2017ApJ...850..125Z -
Astrophys. J., 850, 125-125 (2017/December-1)
Low-mass pre-He white dwarf stars in Kepler eclipsing binaries with multi-periodic pulsations.
ZHANG X.B., FU J.N., LIU N., LUO C.Q. and REN A.B.
Abstract (from CDS):
We report the discovery of two thermally bloated low-mass pre-He white dwarfs (WDs) in two eclipsing binaries, KIC 10989032 and KIC 8087799. Based on the Kepler long-cadence photometry, we determined comprehensive photometric solutions of the two binary systems. The light curve analysis reveals that KIC 10989032 is a partially eclipsed detached binary system containing a probable low-mass WD with the temperature of about 10,300 K. Having a WD with the temperature of about 13,300, KKIC 8087799 is typical of an EL CVn system. By utilizing radial velocity measurements available for the A-type primary star of KIC 10989032, the mass and radius of the WD component are determined to be 0.24±0.02 M☉ and 0.50±0.01 R☉, respectively. The values of mass and radius of the WD in KIC 8087799 are estimated as 0.16 ± 0.02 M☉ and 0.21 ± 0.01 R☉, respectively, according to the effective temperature and mean density of the A-type star derived from the photometric solution. We therefore introduce KIC 10989032 and KIC 8087799 as the eleventh and twelfth dA+WD eclipsing binaries in the Kepler field. Moreover, both binaries display marked multi-periodic pulsations superimposed on binary effects. A preliminary frequency analysis is applied to the light residuals when subtracting the synthetic eclipsing light curves from the observations, revealing that the light pulsations of the two systems are both due to the δ Sct-type primaries. We hence classify KIC 10989032 and KIC 8087799 as two WD+δ Sct binaries.
Abstract Copyright:
© 2017. The American Astronomical Society. All rights reserved.
Journal keyword(s):
binaries: eclipsing - stars: individual: (KIC 10989032, KIC 8087799) - stars: oscillations - white dwarfs - white dwarfs
CDS comments:
KIC 4169561 is a misprint for KIC 4169521.
Simbad objects:
14
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2017ApJ...850..125Z and select 'bookmark this link' or equivalent in the popup menu