Cygnus A radiogalaxy — A Hidden Giant in the Night Sky

When an amateur astronomer discovers astrophotography, the first instinct is usually to photograph the bright, well-known objects in the night sky — the Orion Nebula, the Andromeda Galaxy, the Pleiades, the Hercules Cluster, and so on. I did the same. Over time, however, I became more interested in less popular targets — objects with very few photos available online. These are mostly distant, faint galaxies often overlooked by astrophotographers. 

One of these objects is the radio galaxy Cygnus A, which I’d like to share with you today.

Cygnus A (3C 405) is a powerful and compact radio source discovered by Grote Reber in 1939. It was the first radio galaxy to be identified with an optical object — an elliptical galaxy. Located in the constellation Cygnus, it lies about 600 million light-years from Earth. Cygnus A is the most powerful extragalactic radio source within its constellation and among the strongest known in the entire sky. The striking difference in radio luminosity between the distant Cygnus A and the nearby Andromeda Galaxy later led to the classification of galaxies into two categories: so-called “normal” galaxies, like the Andromeda Nebula, and radio galaxies.

The material for this photo was collected from my balcony in March 2020, during the height of the COVID-19 lockdown. Spring was cold, but the clear skies gave me the time and space to focus on astrophotography.

Equipment Used

• Sky-Watcher MAK180 Maksutov-Cassegrain telescope with Celestron 0.63× focal reducer (effective focal length 1700 mm, f/9.45)

• ZWO ASI174MM monochrome camera

• Astro-Tech AT6IN Newtonian reflector telescope (focal length 600 mm, f/4)

• QHY178C color camera

• QHY mini guide scope

• QHY5L-II guide camera

• Celestron CG-5GT equatorial mount

The luminance channel was captured using the MAK180 telescope and ASI174MM monochrome camera — 639 frames of 20–60 s exposures (a total of 4.7 hours).
The color data were acquired with the AT6IN telescope and QHY178C color camera — 235 frames of 2 minutes each (a total of 7.8 hours).

And here's my humble balcony attempt versus a professional survey (NASA/NASA/STScI) — not quite the same, but it’s fun to see what a small telescope can do.