Caldwell objects
The Caldwell catalogue contains 35 galaxies, 28 open clusters, 18 globular clusters, 12 bright nebulae, one dark nebula, and two supernova remnants. Unlike the Messier objects, these objects cannot be seen in the same night from a single location. However, half-marathons are popular with astronomy clubs, since at least half of the objects are visible from most locations.

Caldwell list
NGC 188 (Caldwell 1)

NGC 188 (C1) is an open cluster in Cepheus. It appears less than 5 degrees from the north celestial pole. The cluster has an apparent magnitude of 10.0 and an apparent size of 15 arcminutes. It lies 5,400 light years away. It is one of the oldest open clusters known, with an estimated age of about 6.8 billion years.

NGC 40 (Caldwell 2): Bow-Tie Nebula

The Bow-Tie Nebula (C2) is a planetary nebula approximately 3,500 light years away in Cepheus. It has an apparent magnitude of 10.7 and an apparent size of 38 by 35 arcseconds. The central star has the spectrum of a carbon-rich Wolf-Rayet star.

NGC 4236 (Caldwell 3)

NGC 4236 (C3) is a barred spiral galaxy about 11.7 million light years away in Draco. It has an apparent magnitude of 10.5 and an apparent size of 21.9 by 7.2 arcminutes. The galaxy is a member of the M81 Group, which also contains Bode’s Galaxy (Messier 81) and the Cigar Galaxy (Messier 82). However, it does not appear close to these galaxies in the sky. It lies near Kappa Draconis, roughly halfway between Kochab in Ursa Minor and Dubhe in Ursa Major.

NGC 7023 (Caldwell 4): Iris Nebula

The Iris Nebula (C4) is a magnitude 6.8 reflection nebula 1,300 light years away in Cepheus. The nebula has an apparent size of 18 arcminutes. The central star, SAO 19158, shines at magnitude 7.4. The New General Catalogue designation NGC 7023 refers to the open cluster embedded in the nebula.

Thanks Kate worth looking into
Steve