The constellation of Cassiopeia rises to considerable altitudes during the course of October evenings. There are a very large number of star clusters in this constellation that are easily visible in quite small telescopes.
Although Charles Messier, in the 1780’s only noted two in his catalogue of around 100 nebulous objects; M52 and M103.
William Herschel, observing at around about this time, discovered over a dozen clusters in Cassiopeia, with an 18 inch telescope. Two of these, at opposite ends of the characteristic w shape of this constellation, are among my favourite objects of this type.
The easiest one to find, in moderate conditions, is the large cluster NGC 663 (RA 01:46, Dec +61:15 epoch 2000). This is less than 2 degrees from M103 and I can usually find it by random sweeping, from M103, with a low power eyepiece in the 16 inch Robertson Reflector at Pex Hill, with a field of view of about 1 degree. It is fairly easy to see in binoculars, even in average conditions, and even a very small telescope should fully resolve the bright stars in this cluster.
On the other side of the w of this constellation, about 3 degrees SSW from beta Cassiopeia, lies the much more difficult cluster NGC 7789 (RA 23:57, Dec +56:44). This is actually listed as being slightly brighter than NGC 663 (6.7 compared to 7.1). However, telescopically, it can be very elusive, unless conditions are very good. Even the 16 inch at Pex Hill sometimes struggles to pick up this object, as the stars seem to be about 2 magnitudes fainter than in NGC 663. On very dark nights, well away from the bright lights of Liverpool, this cluster appears as a ghostly glow in 7×50 binoculars, the individual stars being too faint to discern with this low magnification and small aperture.