The TRENDS High-Contrast Imaging Survey. III. A Faint White Dwarf Companion Orbiting HD 114174
Abstract
The nearby Sun-like star HD 114174 exhibits a strong and persistent Doppler acceleration indicating the presence of an unseen distant companion. We have acquired high-contrast imaging observations of this star using NIRC2 at Keck and report the direct detection of the body responsible for causing the "trend." HD 114174 B has a projected separation of 692 ± 9 mas (18.1 AU) and is 10.75 ± 0.12 mag (contrast of 5 × 10^(–5)) fainter than its host in the K-band, requiring aggressive point-spread function subtraction to identify. Our astrometric time baseline of 1.4 yr demonstrates physical association through common proper motion. We find that the companion has absolute magnitude, M_J = 13.97 ± 0.11, and colors, J – K = 0.12 ± 0.16 mag. These characteristics are consistent with an ≈T3 dwarf, initially leading us to believe that HD 114174 B was a substellar object. However, a dynamical analysis that combines radial velocity measurements with available imaging data indicates a minimum mass of 0.260 ± 0.010 M_☉. We conclude that HD 114174 B must be a white dwarf. Assuming a hydrogen-rich composition, atmospheric and evolutionary model fits yield an effective temperature T_(eff) = 8200 ± 4000 K, surface gravity log g = 8.90 ± 0.02, and cooling age of t_c ≈ 3.4 Gyr, which is consistent with the 4.7^(+2.3)_(-2.6) Gyr host star isochronal age estimate. HD 114174 B is a benchmark object located only 26.14 ± 0.37 pc from the Sun. It may be studied at a level of detail comparable to Sirius and Procyon, and used to understand the link between the mass of white dwarf remnants with that of their progenitors.
Additional Information
© 2013 American Astronomical Society. Received 2013 May 2; accepted 2013 June 24; published 2013 August 7. We thank Sasha Hinkley for trading NIRC2 observing time that allowed us to acquire observations of HD 114174 B in a complementary bandpass, demonstrating its unusual colors, and Mike Liu for pointing out reference to the Gliese 86 system which shares a similar story as HD 114174 B for being a white dwarf initially characterized as a brown dwarf. The referee, John Subasavage, provided helpful comments that improved the clarity of our manuscript. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. The TRENDS high-contrast imaging program is supported by NASA Origins grant NNX13AB03G. J.A.J. is supported by generous grants from the David and Lucile Packard Foundation and the Alfred P. Sloan Foundation. Data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The Center for Exoplanets and Habitable Worlds is supported by the Pennsylvania State University, the Eberly College of Science, and the Pennsylvania Space Grant Consortium.Attached Files
Published - 0004-637X_774_1_1.pdf
Submitted - 1305.0571v2.pdf
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Additional details
- Eprint ID
- 41495
- Resolver ID
- CaltechAUTHORS:20130924-095847561
- NASA
- NNX13AB03G
- David and Lucile Packard Foundation
- Alfred P. Sloan Foundation
- W. M. Keck Foundation
- Pennsylvania State University
- Eberly College of Science
- Pennsylvania Space Grant Consortium
- Created
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2013-09-24Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field