Terzan 7 is one of about a dozen globular clusters catalogued by Agop Terzan during between 1966 and 1971. These clusters are, by and large, very challenging objects. That said, Terzan 7 is arguably the brightest and easiest of the group. Even across a gulf of more than 70,000 light-years, this globular cluster is fairly obvious in the 18-inch Obsession. My sketch renders a 236X view in the big Dobsonian. Terzan 7 is centered, a 1' diameter soft glow that, after several minutes scrutiny, appears just a skosh salty. A close pair of foreground stars lies at the eastern edge of the 12.0 magnitude cluster. Within its gauzy light, three or four extremely faint stars emerge intermittently with averted vision. 9.9 magnitude HD 180444 glimmers about 4' to the northeast. An 11th magnitude GSC star shines 2' southeast of the globular. Another 30 stars dot the field. You'll find Terzan 7 about 6 degrees southwest of the bright globular cluster, M55. |