The extreme Seyfert galaxy associated with the X-ray source 3A 0557 - 383

A Seyfert galaxy at 1950: $$5^\text h 56^\text m21^\text s$$, − 38° 20′ 15″ with a velocity of recession V₀= 10 000 km s⁻¹ is identified with the X-ray source 3A 0557 – 383. The optical spectrum is very heavily reddened, so that the absolute magnitude, if corrected for extinction, reveals this to be one of the most luminous Seyferts known. It shows a very high mean X-ray luminosity of 10^37.2 W (2–10 keV) and is believed to be variable.