M4 (NGC 6121) Sco globular cluster
Difficulty level 2

Date of observation: 1997/05/05 01:35
Observing site: Kuju
Instruments: 32cm Dobsonian with XL14 at 110x
Width of field: 0.6 degree
This is a very large globular cluster. It is perhaps the largest visible from Japan, except the Omega Globular Cluster. It is 7000 light-years away from our Solar System and one of the nearest globular clusters. Incidentally, M13 is 22,000 years away and the Omega Globular Cluster is at a distance of 16,000 light-years. Because of its close proximity, it is resolved most easily. However, this globular's concentration is rather weak and looks somewhat different from the way M13 is resolved. It is large and appears as a dense open cluster rather than a globular cluster. It also appears as a larger version of M11 with a finer resolution. Its shape is irregular with many rows of stars running south-north. In the central region a conspicuous dark band runs north-south. It is interesting that stars lie all along the edges of this dark band.
M4 (NGC 6121) Sco globular cluster
Difficulty level 2
Date of observation: 1995/05/05
Observing site: Kuju
Transparency/seeing/sky darkness: 4/2/4
Instruments: 30x125 binoculars
Width of field: 1.6 degrees
At this magnification it is well resolved and seems to be one of the globulars most easily resolved. It is not round and rather irregular, and also looks triangular in an overall shape.