James Dunlop discovered NGC 6193 = D 413 = h3640 with his 9-inch f/12 reflector from Parramatta, New South Wales. He reported "A cluster of small stars, with a bright star in the preceding side. A very considerable branch or tail proceeds from the north side, which joins a very large cluster." He did not mention any nebulosity.

On 15 Apr 1836, John Herschel described a "cluster VIII; consists of about a dozen stars 10..11m, and perhaps as many less, with stragglers, which fill field. In its preceding part is a fine double star [HJ 4876] and yet more preceding is a vL, faint nebula [NGC 6188], in which the preceding part of the cl is involved."

200/250mm - 8" (7/13/91 - Southern Baja): 45 stars in a 15' diameter at 63x. Includes a bright mag 5.6/6.8 double star at 10" separation and mag 7 SAO 227038 6' W. A circular group of seven fairly bright stars is just east of the double star with a fainter curved string of stars in the center. There are several brighter stragglers on the east side. The cluster is generally spread out with no rich regions. Extensive nebulosity is involved (see NGC 6188).

8" (7/17/82): three bright stars including h4876 (6.0/7.0 at 10"). Many faint stars are visible with averted vision. Includes emission/reflection nebula NGC 6188. This star-forming region is extremely far south for viewing from the Sierra foothills (only 2.5° above the horizon)!

400/500mm - 18" (7/10/02 - Magellan Observatory, Australia): at 117x, ~75 stars were visible in a 15' field surrounding the ionizing source HJ 4876, a bright 10" double consisting of mag 5.6 O3-type HD 150136 and mag 6.8 O6-type HD 150135. I also saw a couple of very faint mag 15 companions to the bright double. In addition, a 7th mag star (HD 150041) is on the west side of the cluster. These three bright stars are encased in nebulous halos that respond to a UHC filter (indicating emission). The cluster itself is scattered with no central concentration and includes a mixture of mostly bright and some very faint stars. A perfect ellipse of moderately bright stars is just southwest of the main portion of the cluster. Interestingly, the center of this ring is mostly free of the nebulosity (RCW 108) that permeates the field (see NGC 6188 for description) . The RCW 108 complex is in the Ara OB1 association, one of the youngest and closest star-forming regions.

Notes by Steve Gottlieb