NGC/IC Project Restoration Effort

===== NGC 6231. See NGC 6227.

===== NGC 6231 11" (8/8/04 - Haleakala Crater): at 103x this is a stunning open cluster with a half-dozen stars brighter than 7th magnitude and a dozen mag 8 or brighter. This bright subset is set over a rich carpet of 100-150 fainter stars in a roughly 20' field. This bright naked-eye cluster sits just north of Zeta Scorpii. Extending to the north following a chain of stars is the sprawling open cluster Tr 24 (60' diameter) that includes IC 4628, a large irregular HII region (see notes below). 18" (6/12/10): at 108x Tr 24 is a striking, very large, bright scattered group that overfills the 56' field. A number of the stars appeared to be grouped into long chains with smaller knots and concentrations including vdBh 202 and vdBH 205. On the northern side is IC 4628, a very large, irregular HII nebula that shows up best with a UHC filter. On the south edge of IC 4628 is mag 7.2 HD 152723 and 5' SW is a distinctive 8' string oriented NW-SE. About 20' S of the mag 7.2 star is a mag 6.2 star (V861 Sco) and to the NW is another 20' string extending WNW. To the south of this string is another 20' string oriented NW-SE that includes vdBH 202. IC 4628 is a large, HII region embedded on the northern half of Tr 24. At 108x and UHC filter IC 4628 stood out as a very large, fairly bright glow within Tr 24. The main glow was elongated E-W, roughly 30'x12' with mag 7.2 HD 152723 just off the south side. A number of mag 8-10 stars are embedded along the SW and west end of the nebulosity. A fainter extension begins on the east end and extends NE for ~15', ending in a brighter patch with several stars involved. 11" (8/8/04 - Haleakala Crater): at 103x the 40' field to the north of NGC 6231is filled with a huge, scattered grouping with no distinct boundaries. 8" (7/13/91 - Southern Baja): over 100 stars mag 8-12. Bright, very large, scattered. Divided into two main groups and fills the 40' field. Emission nebula IC 4628 is involved on the north side (seen from Baja) and a trail of stars extends towards NGC 6231. 8" (6/27/81): bright, large, scattered cluster in two main groups. 17.5" (7/4/86): 100 stars at 84x in the main part including 10 bright stars. Impressive cluster at low power. 13" (7/5/83): five bright stars are in the cluster with a dozen stars in the central portion and 50 stars in a 20' field. There is a 1¡ field to the NW and NE consisting of fairly bright stars = NGC 6227 and Tr 24 = H12. 8" (7/13/91 - Southern Baja): bright group of stars in center like jewels over rich sprays of stars, excellent low power field. Located 30' N of Zeta Scorpii. Partially resolved in 8x50 finder. 8" (6/27/81): impressive cluster at 100x with a bright group of 8 stars in the center. Partially resolved in the 8x50 finder. Naked-eye (numerous times): this is an easy naked eye cluster, even from northern California, looking like a comet heading north from Zeta Scorpii. From further south (southern Baja or southern Hemisphere), it is a very prominent naked-eye cluster.