A DEEPLY ECLIPSING DETACHED DOUBLE HELIUM WHITE DWARF BINARY

Journal Article · Sun Jul 10 00:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/735/2/L30· OSTI ID:21562556

Parsons, S G; Marsh, T R; Gaensicke, B T ^[1]; Drake, A J ^[2]; Koester, D ^[3]

---

1. Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom)
2. California Institute of Technology, 1200 E. California Blvd, CA 91225 (United States)
3. Institut fuer Theoretische Physik und Astrophysik, Universitaet Kiel (Germany)

Using Liverpool Telescope+RISE photometry we identify the 2.78 hr period binary star CSS 41177 as a detached eclipsing double white dwarf binary with a 21,100 K primary star and a 10,500 K secondary star. This makes CSS 41177 only the second known eclipsing double white dwarf binary after NLTT 11748. The 2 minute long primary eclipse is 40% deep and the secondary eclipse 10% deep. From Gemini+GMOS spectroscopy, we measure the radial velocities of both components of the binary from the H{alpha} absorption line cores. These measurements, combined with the light curve information, yield white dwarf masses of M{sub 1} = 0.283 {+-} 0.064 M{sub sun} and M{sub 2} = 0.274 {+-} 0.034 M{sub sun}, making them both helium core white dwarfs. As an eclipsing, double-lined spectroscopic binary, CSS 41177 is ideally suited to measuring precise, model-independent masses and radii. The two white dwarfs will merge in roughly 1.1 Gyr to form a single sdB star.

• OSTI ID: 21562556
• Journal Information: Astrophysical Journal Letters, Vol. 735, Issue 2; Other Information: DOI: 10.1088/2041-8205/735/2/L30; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BINARY STARS
ECLIPSE
HELIUM
MASS
PHOTOMETRY
RADIAL VELOCITY
WHITE DWARF STARS
DWARF STARS
ELEMENTS
FLUIDS
GASES
NONMETALS
RARE GASES
STARS
VELOCITY