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

S. Lacour; S. Meimon; E. Thiébaut; G. Perrin; T. Verhoelst; E. Pedretti; P.~A. Schuller; L. Mugnier; J. Monnier; J.~P. Berger; X. Haubois; A. Poncelet; G. Le Besnerais; K. Eriksson; R. Millan-Gabet; S. Ragland; M. Lacasse; W. Traub

doi:10.1051/0004-6361:200809611

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

S. Lacour, S. Meimon, E. Thiébaut, G. Perrin, T. Verhoelst, E. Pedretti, P.~A. Schuller, L. Mugnier, J. Monnier, J.~P. Berger, X. Haubois, A. Poncelet, G. Le Besnerais, K. Eriksson, R. Millan-Gabet, S. Ragland, M. Lacasse, W. Traub

School of Engineering & Physical Sciences

Research output: Contribution to journal › Article › peer-review

45 Citations (Scopus)

Abstract

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$\approx$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$\pm$0.21 was derived, corresponding to an effective temperature of $T_{\rm
eff}$ = 4295$\pm$26 K. No companion was detected from the closure phases, with an upper limit on the brightness ratio of 8$\times$10-4 at 1 AU. The dynamic range at such distance from the photosphere was established as 1.5$\times$10-4 (1$\sigma\,$rms). An upper limit of 1.7$\times$10-3 was also derived for the level of brightness asymmetries present in the photosphere.

Original language	Undefined/Unknown
Pages (from-to)	561-570
Number of pages	10
Journal	Astronomy and Astrophysics
Volume	485
Issue number	2
DOIs	https://doi.org/10.1051/0004-6361:200809611
Publication status	Published - 22 Apr 2008

Keywords

techniques: interferometric, stars: fundamental parameters, infrared: stars, stars: individual: Arcturus

Access to Document

10.1051/0004-6361:200809611

Cite this

Lacour, S., Meimon, S., Thiébaut, E., Perrin, G., Verhoelst, T., Pedretti, E., Schuller, P. A., Mugnier, L., Monnier, J., Berger, J. P., Haubois, X., Poncelet, A., Le Besnerais, G., Eriksson, K., Millan-Gabet, R., Ragland, S., Lacasse, M., & Traub, W. (2008). The limb-darkened Arcturus: imaging with the IOTA/IONIC interferometer. Astronomy and Astrophysics, 485(2), 561-570. https://doi.org/10.1051/0004-6361:200809611

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title = "The limb-darkened Arcturus: imaging with the IOTA/IONIC interferometer",

abstract = "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$\approx$35) of Arcturus. Atmospheric models and prescriptions were fitted to the data to derive the brightness distribution of the photosphere. Image reconstruction was performed using two software algorithms: WISARD and MIRA.Results. An achromatic power law proved to be a good model of the brightness distribution, with a limb darkening compatible with the one derived from atmospheric model simulations using our mARCS model. A Rosseland diameter of 21.05$\pm$0.21 was derived, corresponding to an effective temperature of $T_{\rmeff}$ = 4295$\pm$26 K. No companion was detected from the closure phases, with an upper limit on the brightness ratio of 8$\times$10-4 at 1 AU. The dynamic range at such distance from the photosphere was established as 1.5$\times$10-4 (1$\sigma\,$rms). An upper limit of 1.7$\times$10-3 was also derived for the level of brightness asymmetries present in the photosphere. ",

keywords = "techniques: interferometric, stars: fundamental parameters, infrared: stars, stars: individual: Arcturus",

author = "S. Lacour and S. Meimon and E. Thi{\'e}baut and G. Perrin and T. Verhoelst and E. Pedretti and P.~A. Schuller and L. Mugnier and J. Monnier and J.~P. Berger and X. Haubois and A. Poncelet and {Le Besnerais}, G. and K. Eriksson and R. Millan-Gabet and S. Ragland and M. Lacasse and W. Traub",

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day = "22",

doi = "10.1051/0004-6361:200809611",

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Lacour, S, Meimon, S, Thiébaut, E, Perrin, G, Verhoelst, T, Pedretti, E, Schuller, PA, Mugnier, L, Monnier, J, Berger, JP, Haubois, X, Poncelet, A, Le Besnerais, G, Eriksson, K, Millan-Gabet, R, Ragland, S, Lacasse, M & Traub, W 2008, 'The limb-darkened Arcturus: imaging with the IOTA/IONIC interferometer', Astronomy and Astrophysics, vol. 485, no. 2, pp. 561-570. https://doi.org/10.1051/0004-6361:200809611

TY - JOUR

T1 - The limb-darkened Arcturus: imaging with the IOTA/IONIC interferometer

AU - Lacour, S.

AU - Meimon, S.

AU - Thiébaut, E.

AU - Perrin, G.

AU - Verhoelst, T.

AU - Pedretti, E.

AU - Schuller, P.~A.

AU - Mugnier, L.

AU - Monnier, J.

AU - Berger, J.~P.

AU - Haubois, X.

AU - Poncelet, A.

AU - Le Besnerais, G.

AU - Eriksson, K.

AU - Millan-Gabet, R.

AU - Ragland, S.

AU - Lacasse, M.

AU - Traub, W.

PY - 2008/4/22

Y1 - 2008/4/22

N2 - 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$\approx$35) of Arcturus. Atmospheric models and prescriptions were fitted to the data to derive the brightness distribution of the photosphere. Image reconstruction was performed using two software algorithms: WISARD and MIRA.Results. An achromatic power law proved to be a good model of the brightness distribution, with a limb darkening compatible with the one derived from atmospheric model simulations using our mARCS model. A Rosseland diameter of 21.05$\pm$0.21 was derived, corresponding to an effective temperature of $T_{\rmeff}$ = 4295$\pm$26 K. No companion was detected from the closure phases, with an upper limit on the brightness ratio of 8$\times$10-4 at 1 AU. The dynamic range at such distance from the photosphere was established as 1.5$\times$10-4 (1$\sigma\,$rms). An upper limit of 1.7$\times$10-3 was also derived for the level of brightness asymmetries present in the photosphere.

AB - 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$\approx$35) of Arcturus. Atmospheric models and prescriptions were fitted to the data to derive the brightness distribution of the photosphere. Image reconstruction was performed using two software algorithms: WISARD and MIRA.Results. An achromatic power law proved to be a good model of the brightness distribution, with a limb darkening compatible with the one derived from atmospheric model simulations using our mARCS model. A Rosseland diameter of 21.05$\pm$0.21 was derived, corresponding to an effective temperature of $T_{\rmeff}$ = 4295$\pm$26 K. No companion was detected from the closure phases, with an upper limit on the brightness ratio of 8$\times$10-4 at 1 AU. The dynamic range at such distance from the photosphere was established as 1.5$\times$10-4 (1$\sigma\,$rms). An upper limit of 1.7$\times$10-3 was also derived for the level of brightness asymmetries present in the photosphere.

KW - techniques: interferometric, stars: fundamental parameters, infrared: stars, stars: individual: Arcturus

U2 - 10.1051/0004-6361:200809611

DO - 10.1051/0004-6361:200809611

M3 - Article

SN - 0004-6361

VL - 485

SP - 561

EP - 570

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

IS - 2

ER -