A&A 570, A104 (2014) Astronomy DOI: 10.1051/0004-6361/201423772 & c ESO 2014 Astrophysics Improving the surface brightness-color relation for early-type stars using optical interferometry, M. Challouf1,2,N.Nardetto1,D.Mourard1, D. Graczyk3, H. Aroui2, O. Chesneau1,O.Delaa1, G. Pietrzynski´ 3,4, W. Gieren3,R.Ligi1, A. Meilland1, K. Perraut5,6, I. Tallon-Bosc7,8, H. McAlister9,10, T. ten Brummelaar10, J. Sturmann10,L.Sturmann10, N. Turner10, C. Farrington10,N.Vargas10, and N. Scott10 1 Laboratoire Lagrange, UMR 7293, UNS/CNRS/OCA, 06300 Nice, France e-mail:
[email protected] 2 Laboratoire Dynamique Moléculaire et Matériaux Photoniques, UR11ES03, Université de Tunis/ESSTT, Tunisie 3 Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción, Paraguay 4 Warsaw University Observatory, AL. Ujazdowskie 4, 00-478 Warsaw, Poland 5 Univ. Grenoble Alpes, IPAG, 38000 Grenoble, France 6 CNRS, IPAG, 38000 Grenoble, France 7 Université Lyon 1, Observatoire de Lyon, 9 avenue Charles André, 69230 Saint Genis Laval, France 8 CNRS/UMR 5574, Centre de Recherche Astroph. de Lyon, École Normale Supérieure, 69007 Lyon, France 9 Georgia State University, PO Box 3969, Atlanta GA 30302-3969, USA 10 CHARA Array, Mount Wilson Observatory, 91023 Mount Wilson CA, USA Received 7 March 2014 / Accepted 2 September 2014 ABSTRACT Context. The method of distance determination of eclipsing binaries consists in combining the radii of both components determined from spectro-photometric observations with their respective angular diameters derived from the surface brightness-color relation (SBC). However, the largest limitation of the method comes from the uncertainty on the SBC relation: about 2% for late-type stars (or 0.04 magnitude) and more than 10% for early-type stars (or 0.2 mag).