NPM1G -10.0586: an emission-line companion of the Seyfert galaxy Mrk 509
  We report spectral observations of the galaxy NPM1G -10.0586, the main candidate-companion of Mrk 509. Mrk 509 is a Seyfert galaxy showing no evidence of morphological perturbations of the potential. The spectrum of NPM1G -10.0586 obtained by us is emission-line. The derived weighted mean redshift is 0.03313 +- 0.00023, which makes NPM1G -10.0586 a physical companion of Mrk 509. 
Lyuba Slavcheva-Mihova, Boyko Mihov
astro-ph.CO