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Stellar Parameters for HD 69830, a Nearby Star with Three Neptune Mass Planets and an Asteroid Belt

Tanner, Angelle and Boyajian, Tabetha S. and von Braun, Kaspar and Kane, Stephen and Brewer, John M. and Farrington, Chris and van Belle, Gerard T. and Beichman, Charles A. and Fischer, Debra and ten Brummelaar, Theo A. and McAlister, Harold A. and Schaefer, Gail (2015) Stellar Parameters for HD 69830, a Nearby Star with Three Neptune Mass Planets and an Asteroid Belt. Astrophysical Journal, 800 (2). Art. No. 115. ISSN 0004-637X.

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We used the CHARA Array to directly measure the angular diameter of HD 69830, home to three Neptune mass planets and an asteroid belt. Our measurement of 0.674 ± 0.014 mas for the limb-darkened angular diameter of this star leads to a physical radius of R_* = 0.9058 ± 0.0190 R_☉ and luminosity of L_* = 0.622 ± 0.014 L_☉ when combined with a fit to the spectral energy distribution of the star. Placing these observed values on an Hertzsprung-Russel diagram along with stellar evolution isochrones produces an age of 10.6 ± 4 Gyr and mass of 0.863 ± 0.043 M_☉. We use archival optical echelle spectra of HD 69830 along with an iterative spectral fitting technique to measure the iron abundance ([Fe/H] = –0.04 ± 0.03), effective temperature (5385 ± 44 K), and surface gravity (log g = 4.49 ± 0.06). We use these new values for the temperature and luminosity to calculate a more precise age of 7.5 ± 3 Gyr. Applying the values of stellar luminosity and radius to recent models on the optimistic location of the habitable zone produces a range of 0.61-1.44 AU; partially outside the orbit of the furthest known planet (d) around HD 69830. Finally, we estimate the snow line at a distance of 1.95 ± 0.19 AU, which is outside the orbit of all three planets and its asteroid belt.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Tanner, Angelle0000-0002-2903-2140
Boyajian, Tabetha S.0000-0001-9879-9313
von Braun, Kaspar0000-0002-5823-4630
Kane, Stephen0000-0002-7084-0529
Brewer, John M.0000-0002-9873-1471
Farrington, Chris0000-0001-9939-2830
van Belle, Gerard T.0000-0002-8552-158X
Beichman, Charles A.0000-0002-5627-5471
Fischer, Debra0000-0003-2221-0861
ten Brummelaar, Theo A.0000-0002-0114-7915
Additional Information:© 2015 American Astronomical Society. Received 2014 October 16; accepted 2014 December 15; published 2015 February 18. We thank the anonymous referee for insightful comments pertaining to this manuscript. This research has made use of the JSDC Jean-Marie Mariotti Center database, available at The CHARA Array is funded by the National Science Foundation through NSF grants AST-0908253 and AST 1211129, and by Georgia State University through the College of Arts and Sciences. TSB acknowledges support provided through NASA grant ADAP12-0172. This research has made use of the Habitable Zone Gallery at
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
NSFAST 1211129
Georgia State UniversityUNSPECIFIED
Subject Keywords: stars: fundamental parameters; techniques: interferometric
Issue or Number:2
Record Number:CaltechAUTHORS:20150323-150530374
Persistent URL:
Official Citation: Stellar Parameters for HD 69830, a Nearby Star with Three Neptune Mass Planets and an Asteroid Belt Angelle Tanner et al. 2015 ApJ 800 115
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:55989
Deposited By: Ruth Sustaita
Deposited On:23 Mar 2015 22:26
Last Modified:27 Nov 2019 18:55

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