Search for Sirius companions

January 31, 1862, the white dwarf Sirius-B, was discovered around the Sirius star, using the first large modern telescope. Since this discovery, many direct or indirect observations came to suggest the existence of a second companion around the brilliant star. The presence of another small star could in particular explain a change of color of Sirius suggested by historical texts. A team of astronomers of the CEA Service of Astrophysics, Institute of Celestial mechanics (IMC) and Observatory of Paris-Meudon (OPM) have just obtained a new image of the star field around Sirius using a coronographic device. This image, compared with a preceding observation carried out 13 years earlier, allowed for the first time, by using the large proper motion of Sirius, to eliminate certain possible candidates and to constrain the possible characteristics of the second companion. An unexplored star field The most central area (0.9) (Bonnet-Bidaud & Gry 1991). According to the orientation of this orbit on the sky, there is a possibility that a companion is currently at a very short projected distance of Sirius. A program is currently carried out with ESO to observe the area nearest to Sirius with high spatial resolution with adaptive optics. Let us note that Kuchner and Brown (2000, PASP 112, 827) also recently obtained constraints on the possible companions of Sirius, with the Space Telescope (NICMOS). Contacts Jean-Marc Bonnet-Bidaud Service d’Astrophysique, DSM/DAPNIA/Sap, CEA Saclay François Colas, Obs de Paris, IMCCE-BDL Jean Lecacheux, Observatoire de Paris, DESPA