A typical QSO - PKS 1117-248

With ground-based telescopes, quasars are typically boring until you measure their spectrum. As a pretty typical example, this is the radio-loud quasar PKS 1117-248 at redshift z=0.466. I marked it to reduce puzzlement - this image shows why various subterfuges involving radio emission, X-rays, colors, or spectra are needed to pick out quasars wholesale from foreground stars. Even at this modest redshift, there's not much of a host galaxy or surrounding group visible to make it stand out.

This is a red-light CCD image taken with the 3.6-meter telescope of the European Southern Observatory. The image covers an area 2.9 by 2.9 arcminutes. The limiting magnitude is about R=23.5.

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