MagAO IMAGING OF LONG-PERIOD OBJECTS (MILO). II. A PUZZLING WHITE DWARF AROUND THE SUN-LIKE STAR HD 11112

Journal Article · Thu Nov 10 00:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/831/2/177· OSTI ID:22667653

Rodigas, Timothy J.; Arriagada, Pamela; Faherty, Jacqueline K.; Weinberger, Alycia; Butler, R. Paul ^[1]; Bergeron, P.; Simon, Amélie ^[2]; Anglada-Escudé, Guillem ^[3]; Mamajek, Eric E. ^[4]; Males, Jared R.; Morzinski, Katie; Close, Laird M.; Hinz, Philip M. ^[5]; Bailey, Jeremy; Tinney, C. G.; Wittenmyer, Rob ^[6]; Carter, Brad ^[7]; Jenkins, James S. ^[8]; Jones, Hugh ^[9]; O’Toole, Simon ^[10] ; others, and

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1. Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015 (United States)
2. Département de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, Québec H3C 3J7 (Canada)
3. School of Physics and Astronomy, Queen Mary, University of London, 327 Mile End Road, London (United Kingdom)
4. Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171 (United States)
5. Steward Observatory, The University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States)
6. Exoplanetary Science at UNSW, School of Physics, UNSW Australia, Sydney, NSW 2052 (Australia)
7. Computational Engineering and Science Research Centre, University of Southern Queensland, Springfield, QLD 4300 (Australia)
8. Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Las Condes, Santiago (Chile)
9. Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, Herts AL10 9AB (United Kingdom)
10. Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia)

HD 11112 is an old, Sun-like star that has a long-term radial velocity (RV) trend indicative of a massive companion on a wide orbit. Here we present direct images of the source responsible for the trend using the Magellan Adaptive Optics system. We detect the object (HD 11112B) at a separation of 2.″2 (100 au) at multiple wavelengths spanning 0.6–4 μ m and show that it is most likely a gravitationally bound cool white dwarf. Modeling its spectral energy distribution suggests that its mass is 0.9–1.1 M {sub ⊙}, which corresponds to very high eccentricity, near edge-on orbits from a Markov chain Monte Carlo analysis of the RV and imaging data together. The total age of the white dwarf is >2 σ , which is discrepant with that of the primary star under most assumptions. The problem can be resolved if the white dwarf progenitor was initially a double white dwarf binary that then merged into the observed high-mass white dwarf. HD 11112B is a unique and intriguing benchmark object that can be used to calibrate atmospheric and evolutionary models of cool white dwarfs and should thus continue to be monitored by RV and direct imaging over the coming years.

• OSTI ID: 22667653
• Journal Information: Astrophysical Journal, Vol. 831, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BENCHMARKS
ENERGY SPECTRA
MASS
MONTE CARLO METHOD
OPTICS
ORBITS
RADIAL VELOCITY
RESOLUTION
SIMULATION
SUN
WAVELENGTHS
WHITE DWARF STARS