The true nature of CSL-1
  On January 12 2006, the Hubble Space Telescope observed the peculiar double extragalactic object CSL-1, suspected to be the result of gravitational lensing by a cosmic string. The high resolution image shows that the object is actually a pair of interacting giant elliptical galaxies. In spite of the weird similarities of the energy and light distributions and of the radial velocities of the two components, CSL-1 is not the lensing of an elliptical galaxy by a cosmic string. 
M. V. Sazhin, M. Capaccioli, G. Longo, M. Paolillo, O. S. Khovanskaya,   N. A. Grogin, E. J. Schreier, G. Covone