Researchers from several American scientific centers, including university of California, presented results of supervision over a place of flash of supernova M51 in a galaxy. Supervision was conducted with help of Hubble telescope, rather small automatic telescope on a surface of planet. Flash of the supernova was noticed on May 31, 2011 and it was seen only by owners of big telescopes as visible brightness of a star reached only to 12. Astronomers received a range of radiation supernova and by absence in it characteristic lines of hydrogen determined accident type: IIb. It means, that the disappearance of star was with a certain partner, who drew on itself considerable part of a hydrogen cover then the part, which has remained and consisting mainly from helium. The subsequent comparisons of a place of flash to the previous pictures allowed to make the assumption that the supernova was generated by a yellow supergiant. The long distance to a galaxy, to equal 23 million light years, didn’t allow to receive detailed images of a place of flash but when afterglow decreased, and astronomers got access to Hubble, the picture cleared up. The yellow star disappeared finally and now on its place there has to be a black hole. And here the partner, that is the second star in double system, had to remain on a place. The calculations, which have been carried out by researchers, show possibility of detection of the escaped star by the end of 2013 whereas a light echo, flash reflection from gas or dust clouds, meanwhile it wasn’t succeeded to mark.