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The Angular Diameter of λ Boötis

Ciardi, David R. and van Belle, Gerard T. and Boden, Andrew F. and ten Brummelaar, T. and McAlister, H. A. and Bagnuolo, W. G., Jr. and Goldfinger, P. J. and Sturmann, J. (2007) The Angular Diameter of λ Boötis. Astrophysical Journal, 659 (2). pp. 1623-1628. ISSN 0004-637X. doi:10.1086/512077.

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Using the CHARA Array and the Palomar Testbed Interferometer, the chemically peculiar star λ Boötis has been spatially resolved. We have measured the limb darkened angular diameter to be θ_(LD) = 0.533 ± 0.029 mas, corresponding to a linear radius of R_* = 1.70 ± 0.10 R_⊙. The measured angular diameter yields an effective temperature for λ Boo of T_(eff) = 8887 ± 242 K. Based on literature surface gravity estimates spanning log g = 4.0-4.2 cm s^(-2), we have derived a stellar mass range of M_* = 1.1-1.7 M_⊙. For a given surface gravity, the linear radius uncertainty contributes approximately σ(M_*) = 0.1-0.2 M to the total mass uncertainty. The uncertainty in the mass (i.e., the range of derived masses) is primarily a result of the uncertainty in the surface gravity. The upper bound of our derived mass range (log g = 4.2, M_* = 1.7 ± 0.2 M_⊙) is consistent with 100-300 Myr solar metallicity evolutionary models. The midrange of our derived masses (log g = 4.1, M_* = 1.3 ± 0.2 M_⊙) is consistent with 2-3 Gyr metal-poor evolutionary models. A more definitive surface gravity determination is required to determine a more precise mass for λ Boo.

Item Type:Article
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Ciardi, David R.0000-0002-5741-3047
van Belle, Gerard T.0000-0002-8552-158X
ten Brummelaar, T.0000-0002-0114-7915
Additional Information:© 2007 The American Astronomical Society. Received 2005 December 15; accepted 2006 December 27. The authors would like to thank the entire staff at the CHARA Array for without them this work would not have been possible. Portions of this work were performed at the California Institute of Technology under contract with the National Aeronautics and Space Administration. This research has been supported by National Science Foundation grants AST-0307562 and AST-0606958 to Georgia State University. Additional support has been received from the Research Program Enhancement program administered by the Vice President for Research at Georgia State University. Work done with the Palomar Testbed Interferometer was performed at the Michelson Science Center, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Interferometer data were obtained at Palomar Observatory using the NASA PTI, supported by NASA contracts to the Jet Propulsion Laboratory. Science operations with PTI are conducted through the efforts of the PTI Collaboration, and we acknowledge the invaluable contributions of our PTI colleagues. This research has made use of the NASA/ IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research has made use of data obtained from the High Energy Astrophysics Science Archive Research Center (HEASARC), provided by NASA’s Goddard Space Flight Center. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Subject Keywords:circumstellar matter; infrared : stars; stars : fundamental parameters; stars : individual (lambda Bootis); techniques : interferometric
Issue or Number:2
Record Number:CaltechAUTHORS:20091028-141400036
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Official Citation:The Angular Diameter of λ Boötis David R. Ciardi, Gerard T. van Belle, Andrew F. Boden, T. ten Brummelaar, H. A. McAlister, W. G. Bagnuolo, Jr., P. J. Goldfinger, J. Sturmann, L. Sturmann, N. Turner, D. H. Berger, R. R. Thompson, and S. T. Ridgway 2007 ApJ 659 1623-1628 doi: 10.1086/512077
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:16512
Deposited By: Tony Diaz
Deposited On:29 Oct 2009 20:24
Last Modified:08 Nov 2021 23:27

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