From Wikipedia: "Omega Centauri ( NGC 5139, or Caldwell 80) is a globular cluster in the constellation of Centaurus that was first identified as a non-stellar object by Edmond Halley in...
NGC 2392 is a small bipolar double-shell planetary nebula located near the δ (delta) star of Gemini. This nebula was first spotted in 1787 and is about 10,000 years old. At magnitude 9....