New Defender's Study Bible Notes
9:9 maketh Arcturus. God not only created and named the stars (e.g., Isaiah 40:26), but also the constellations (also see Job 38:31-33). This fact surely relates to the fact that God created the stars as “signs” (not in the astrological sense but in the evangelical sense), as repositories in the skies of God’s primeval promises of the coming Savior and restoration of the fallen creation.
9:9 chambers of the south. The word usually suggests a distinct room, so probably here refers to the many majestic constellations in the southern sky, opposite to the region containing the bright constellation Orion and the nearby Pleiades (see also Job 38:31). Near the latter is also the group of stars known as the Great Bear, or sometimes as the Ploughman. This group is actually what is meant by Arcturus.