Bright Quasar 3C 273 - May 19, 2017

This photograph of the night sky shows the farthest object I'll ever be able to photograph. The object is a bright quasar (quasi-stellar) that goes by the descriptive name of 3C 273. The name shows that this is the 273rd entry in the Third Cambridge Catalog of Radio Sources (3C), that was published in 1959. 3C 273 is about 2.4 billion light-years away. We only see it from such a distance because it's about 4 trillion times brighter than the sun. Quasars are high luminosity galaxy nuclei that are brightened by the activity of super massive black holes at their centers.

The top photograph shows the sky as we see it with a black background and white stars. While working on the photograph in Adobe Photoshop, I discovered that I also photographed the faint spiral galaxy, NGC 4420 (in the upper right corner). NGC 4420 is about 50 million light-years away.

The lower photograph is cropped into the area around 3C 273 and is a negative image. This makes it easier for our eyes to distinguish the dimmer stars. I labeled the brightness of some of the dimmest stars I was able to identify using my astronomy software. Higher magnitude numbers are dimmer stars. I marked one of the stars with its distance from a very dim galaxy (PGC 139889) that I was not able to capture so people studying this photograph don't think I was able to photograph the galaxy.

These photographs are combinations of multiple images of the same scene that are averaged together to reduce camera noise. They were taken through my home-made telescope on a tracking mount.

Bright quasar 3C 273 and faint galaxy NGC 4420

Zoomed in and inverted region around the bright quasar 3C 273

Photographer: Rick Scott
Date: May 19, 2017
Camera: Canon EOS 40D digital camera
Exposure: 8 x 15 seconds at ISO 800 in raw mode
Lens: Home-made 10 inch f/4.6 Lurie-Houghton Telescope
Mount: Losmandy G-11 equatorial with Gemini 2
Software: Adobe Photoshop CS6 for RAW conversion and image processing

Rick Scott's Natural Images Home Page

Updated: May 21, 2017