AAQ Visual Observing Section
Selected Deep Sky Objects In OphiuchusI found this constellation a little hard to navigate my way around, with its lack of bright guide stars in any easily recognizable patterns. However, persevere and you will be rewarded with many fine objects, including over 24 recognised globular clusters. All observations were made with a 150 mm f/8 refractor. IC 4665 (17h 46.3m RA, 05° 43' Dec) Using a wide field eyepiece you should be able to see 15-20 stars making up this bright open cluster. CR 350 (17h 48.1m RA, 01° 18' Dec) This cluster covers a similar area as IC 4665, but the similar number of stars that make it up are of fainter magnitudes. 61 Oph. (17h 44.6m RA, 02° 35' Dec) This beautiful white pair of similar magnitude stars is easily separated with 40 x. 67 Oph. / H6 2 (18h 00.5m RA, 02° 55' Dec) Set in a beautiful background star field you can use 40x to see a stunning pale yellow primary with a blue secondary. 70 Oph. (18h 05.3m RA, 02° 30' Dec) You will need 120x to see this fine pair with yellow/orange components. This is another pair set in a beautiful star field. M12 (16h 47.2m RA, -01° 57' Dec) An attractive star field surrounds this globular cluster that you should be able to locate with your finderscope. Using 120x I thought it was less compact than many globulars. M10 (16h 57.1m RA, -04° 06' Dec) Both these fine globular clusters are visible in the same finderscope field of view. Slightly brighter than M12, many individual stars can be resolved with 120x. 53 Oph. / Struve 34 (17h 34.5m RA, 09° 34' Dec) Look for the yellow primary and blue secondary colours of this fine double. NGC 6426 (17h 44.9m RA, 03° 10' Dec) I was unable to find this globular cluster, despite being located close by 61 Oph. See how you go, a larger scope may be required. NGC 6366 (17h 27.7m RA, -05° 05' Dec) was a similar result, even with an easy to find magnitude 4.5 star right next door. Tau Oph. (18h 03.1m RA, -08° 11' Dec) 160x could just split this close pair, look for the yellow colour of these two similar magnitude stars. Lambda Oph. (16h 31.1m RA, 01° 58' Dec) This was another difficult pair to separate, needing 240x to just resolve them. Eta Oph. was even closer, with me being unable to split them. NGC 6539 & NGC 6517 (18h 04.8m RA, -07° 35' Dec) Located either side of Tau Oph., the low surface brightness of these two globular clusters made them difficult for me to find. M107 (16h 32.5m RA, -13° 03' Dec) A similar size to M10 & M12, this globular is easily visible with 40x. I was unable to resolve any individual stars with 120x.While using your low power eyepiece, look for the 4 stars in the shape of a cross that bound this cluster. Upsilon Oph. (16h 28m RA, -08° 23' Dec) Although I was unable to separate this pair, check the mag. 6.4 double Struve 2048 which is located close by. While they can be clearly resolved at 120x, you will need to look carefully for the much fainter secondary.
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