Albert Marth discovered NGC 7584 = m 556, along with NGC 7579, on 5 Oct 1864 and noted "eF, vS, stellar." His position is accurate.
400/500mm - 17.5" (10/28/89): very faint, very small, round. A mag 15.5 star (or extremely faint and small galaxy) is off the SW edge. A mag 14 star is 1.3' ENE. Forms a trio with CGCG 406-050 1.1' NNE and NGC 7579 3.5' W. Located 4.6' SSW of mag 7.6 SAO 128095 in the Pegasus II cluster. CGCG 406-050 appeared extremely faint and small, round. A mag 15.5 star is less than 1' WSW and a mag 14 star is 1' SE.
600/800mm - 24" (9/30/16): at 375x; fairly faint, small, round, 20" diameter. In a trio with CGCG 406-050 1.1' NE and NGC 7579 3.5' due W. Located 4.5' SSW of mag 7.6 HD 219728. CGCG 406-050 appeared faint, very small, round, 10"-12" diameter. A mag 14 star is 0.9' SE. Member of the Pegasus II cluster.
Notes by Steve Gottlieb