0309+411, an Mpc-sized core-dominated radio galaxy/quasar.

: The compact radio source 0309+411, located, in projection, on the periphery of the Perseus cluster of galaxies, is found to possess hitherto unknown very large scale radio emission. WSRT observations at 327 MHz and 608 MHz show that the radio core is straddled by two weak lobes extending over an angular size of 9.5'. Optical spectroscopy of the 18th magnitude galaxy identified with the core shows a quasar-like spectrum with strong broad emission lines with a redshift of 0.136. For an Einstein-de Sitter universe and a Hubble constant of 50 km/sec/Mpc the angular size is equivalent to a linear size of 1.8 Mpc making this the quasar with the largest projected size known to date. In addition to this, the source is remarkably for the fact that the radio core is responsible for about 75% of the total emission at a frequency of 5 GHz. The radio core is variable in flux density, has a slightly inverted spectrum and is known to be less than one milliarsecond in size. The core properties suggest that the radio axis of the source is inclined by only a small angle to the line of sight, so that the true deprojected size of the radio source could be several times larger still. We briefly discuss the properties of 03409+411 in the context of the "unified scheme" relating compact and extended radio sources.