A Caltech Library Service

The limb-darkened Arcturus: imaging with the IOTA/IONIC interferometer

Lacour, S. and Meimon, S. and Thiébaut, E. and Perrin, G. and Verhoelst, T. and Pedretti, E. and Schuller, P. A. and Mugnier, L. and Monnier, J. and Berger, J. P. and Haubois, X. and Poncelet, A. and Le Besnerais, G. and Eriksson, K. and Millan-Gabet, R. and Ragland, S. and Lacasse, M. and Traub, W. (2008) The limb-darkened Arcturus: imaging with the IOTA/IONIC interferometer. Astronomy & Astrophysics, 485 (2). pp. 561-570. ISSN 0004-6361.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


Aims. We undertook an H band interferometric examination of Arcturus, a star frequently used as a spatial and spectral calibrator. Methods. Using the IOTA 3 telescope interferometer, we performed spectro-interferometric observations (R ≈ 35) of Arcturus. Atmospheric models and prescriptions were fitted to the data to derive the brightness distribution of the photosphere. Image reconstruction was performed using two software algorithms: Wisard and Mira. Results. An achromatic power law proved to be a good model of the brightness distribution, with a limb darkening compatible with the one derived from atmospheric model simulations using our marcs model. A Rosseland diameter of 21.05 ± 0.21 was derived, corresponding to an effective temperature of Teff = 4295 ± 26 K. No companion was detected from the closure phases, with an upper limit on the brightness ratio of 8 × 10^−4 at 1 AU. The dynamic range at such distance from the photosphere was established as 1.5 × 10^−4 (1σrms). An upper limit of 1.7×10^−3 was also derived for the level of brightness asymmetries present in the photosphere.

Item Type:Article
Related URLs:
URLURL TypeDescription
Lacour, S.0000-0002-6948-0263
Monnier, J.0000-0002-3380-3307
Berger, J. P.0000-0001-5025-0428
Millan-Gabet, R.0000-0003-0447-5866
Lacasse, M.0000-0001-8627-9708
Additional Information:© ESO 2008. Received 19 February 2008 / Accepted 31 March 2008. S.L. acknowledges financial support through a Lavoisier fellowship. This work also received the support of PHASE, the high angular resolution partnership between ONERA, Observatoire de Paris, CNRS and University Denis Diderot Paris 7.
Funding AgencyGrant Number
Lavoisier FellowshipUNSPECIFIED
Subject Keywords:techniques: interferometric; stars: fundamental parameters; infrared: stars; stars: individual: Arcturus
Issue or Number:2
Record Number:CaltechAUTHORS:LACaanda08
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13841
Deposited By: Tony Diaz
Deposited On:03 Apr 2009 21:33
Last Modified:09 Mar 2020 13:18

Repository Staff Only: item control page