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Title: STELLAR PARAMETERS FOR HD 69830, A NEARBY STAR WITH THREE NEPTUNE MASS PLANETS AND AN ASTEROID BELT

Abstract

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 {sub *} = 0.9058 ± 0.0190 R {sub ☉} and luminosity of L {sub *} = 0.622 ± 0.014 L {sub ☉} 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 {sub ☉}. 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,more » which is outside the orbit of all three planets and its asteroid belt.« less

Authors:
 [1]; ; ;  [2]; ;  [3];  [4]; ; ; ;  [5];  [6]
  1. Mississippi State University, Department of Physics and Astronomy, Hilbun Hall, Starkville, MS 39762 (United States)
  2. Department of Astronomy, Yale University, New Haven, CT 06511 (United States)
  3. Lowell Observatory, 1400 W. Mars Hill Road, Flagstaff, AZ 86001 (United States)
  4. Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States)
  5. Center for High Angular Resolution Astronomy and Department of Physics and Astronomy, Georgia State University, P.O. Box 4106, Atlanta, GA 30302-4106 (United States)
  6. NASA Exoplanet Science Institute, California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States)
Publication Date:
OSTI Identifier:
22522101
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 800; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTEROIDS; DIAGRAMS; ELEMENT ABUNDANCE; ENERGY SPECTRA; GRAVITATION; HYDROGEN; IRON; ITERATIVE METHODS; LUMINOSITY; MASS; NEPTUNE PLANET; ORBITS; SNOW; STAR EVOLUTION; STARS

Citation Formats

Tanner, Angelle, Boyajian, Tabetha S., Brewer, John M., Fischer, Debra, Von Braun, Kaspar, Van Belle, Gerard T., Kane, Stephen, Farrington, Chris, Brummelaar, Theo A. ten, McAlister, Harold A., Schaefer, Gail, and Beichman, Charles A. STELLAR PARAMETERS FOR HD 69830, A NEARBY STAR WITH THREE NEPTUNE MASS PLANETS AND AN ASTEROID BELT. United States: N. p., 2015. Web. doi:10.1088/0004-637X/800/2/115.
Tanner, Angelle, Boyajian, Tabetha S., Brewer, John M., Fischer, Debra, Von Braun, Kaspar, Van Belle, Gerard T., Kane, Stephen, Farrington, Chris, Brummelaar, Theo A. ten, McAlister, Harold A., Schaefer, Gail, & Beichman, Charles A. STELLAR PARAMETERS FOR HD 69830, A NEARBY STAR WITH THREE NEPTUNE MASS PLANETS AND AN ASTEROID BELT. United States. https://doi.org/10.1088/0004-637X/800/2/115
Tanner, Angelle, Boyajian, Tabetha S., Brewer, John M., Fischer, Debra, Von Braun, Kaspar, Van Belle, Gerard T., Kane, Stephen, Farrington, Chris, Brummelaar, Theo A. ten, McAlister, Harold A., Schaefer, Gail, and Beichman, Charles A. 2015. "STELLAR PARAMETERS FOR HD 69830, A NEARBY STAR WITH THREE NEPTUNE MASS PLANETS AND AN ASTEROID BELT". United States. https://doi.org/10.1088/0004-637X/800/2/115.
@article{osti_22522101,
title = {STELLAR PARAMETERS FOR HD 69830, A NEARBY STAR WITH THREE NEPTUNE MASS PLANETS AND AN ASTEROID BELT},
author = {Tanner, Angelle and Boyajian, Tabetha S. and Brewer, John M. and Fischer, Debra and Von Braun, Kaspar and Van Belle, Gerard T. and Kane, Stephen and Farrington, Chris and Brummelaar, Theo A. ten and McAlister, Harold A. and Schaefer, Gail and Beichman, Charles A.},
abstractNote = {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 {sub *} = 0.9058 ± 0.0190 R {sub ☉} and luminosity of L {sub *} = 0.622 ± 0.014 L {sub ☉} 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 {sub ☉}. 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.},
doi = {10.1088/0004-637X/800/2/115},
url = {https://www.osti.gov/biblio/22522101}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 800,
place = {United States},
year = {Fri Feb 20 00:00:00 EST 2015},
month = {Fri Feb 20 00:00:00 EST 2015}
}