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.
