3C 285
3C 285 is a radio galaxy in the constellation Canes Venatici, about 1 billion light-years away. It’s a Fanaroff-Riley type II (FR II) radio galaxy hosted by a disturbed spiral galaxy and is the brightest member of a small galaxy group. The galaxy has a distinctive S-shaped envelope that points toward a neighboring galaxy to the northwest, and a gas filament about 26 arcseconds long stretches toward that galaxy.
In optical and ultraviolet light, 3C 285 shows dust lanes — two crossing the galaxy and a third that hides part of the nucleus. Bright knots along the dust lanes indicate regions where new stars are forming.
At the center lies a supermassive black hole, estimated to have a mass of about 50 million solar masses.
Radio observations reveal two lobes with filamentary structures, and a jet is visible in the eastern lobe. A blue star-forming region, called 3C 285/09.6, lies inside the eastern radio lobe. It is thought that the jet compressed dense intergalactic gas and triggered star formation there.
The surrounding gas content, traced by CO imaging, suggests less than about 6.2×10^8 solar masses of star-forming gas; if the current star-formation rate continues, this gas could be used up in under a billion years.
Key measurements: redshift z ≈ 0.0794, radial velocity ≈ 23,800 km/s, distance ≈ 323 Mpc (about 1.05 billion light-years), apparent magnitude V ≈ 16.2, and apparent size ≈ 0.417 by 0.242 arcminutes.
This page was last edited on 2 February 2026, at 21:16 (CET).