This is the third and final blog entry on deep sky objects of Sagittarius. Despite there being dozens of small, faint planetary nebulae, my main interest this time around was clusters. With this and the two previous entries I hope to convince users of larger scopes that there is more to Sagittarius than the many Messier objects it offers. There is a rich life out there for observers beyond the readily obvious. Often the sky background itself is so rich that it sometimes offers more interesting viewing than many of the objects themselves.
oc AL 3: 1'.3; 30 *s: Located at 100x, it was a small, faint cloud. 125x resolves 3 stars. 200x shows 6-8 stars, very faint. Most of the cluster remains unresolved in my 12" mirror.
dn B86: 5' x 5' This is a prominent dark nebula preceding oc 6520, between it and a 6.5 mag. star. The ngc cluster makes a good contrast with the dark nebula. gc E456-38 is also very near.
oc Bo 14: 2'; Vis. 9.3; Br. * mag. 10.3; 11 *s: Viewed at 120x and 187x, a small cloud of faint stars surrounds a bright (mag. 10.3) double star. All members are resolved.
oc Clvd B 113: 15'; 20 *s: V4381 is at the center of this large, scattered group. The variable star is pale orange. A 2nd orange star, darker, is north following. AT 100s two lines of stars converge on the variable in a V shape, though some of these stars are outside the boundary. An easy hop from ngc 6568, this area is great for general sweeping.
oc Bo 14: 2'; Vis. 9.3; Br. * mag. 10.3; 11 *s: Viewed at 120x and 187x, a small cloud of faint stars surrounds a bright (mag. 10.3) double star. All members are resolved.
oc Clvd B 113: 15'; 20 *s: V4381 is at the center of this large, scattered group. The variable star is pale orange. A 2nd orange star, darker, is north following. AT 100s two lines of stars converge on the variable in a V shape, though some of these stars are outside the boundary. An easy hop from ngc 6568, this area is great for general sweeping.
oc Cr 347: 10'; Vis. 8.8 mag; Br. * 10.6; 40 *s: Located at 60x at 100x it was an impressive oval cloud resolving well. At 200x, 20 stars were counted, some very faint, and some of those were double. I was observing in my southern light pollution dome at this point.
oc Cr 351: 8'; Vis. 9.3 mag.; 30 *s: Noted at 60x, the cluster is shaped like an arrowhead or spear point. It is quite large, loose, and has several bright stars, including a mag. 9 one following. 30 stars were counted, many of them in two converging lines.
oc Cr 367: 40'; Vis. 6.4; 30 *s: Seen best at 43x using the 2" eyepiece, this is a lovely, very large group containing many bright stars as well as as all of the preceding faint gn (gn I 1274-75). Use low power and sweep.
oc Cr 371: 20'; Vis. mag. 7; 30 *s: At 60x and 100x, about 60 stars are counted. They are widely scattered and surround a bright yellow star. This is a nice cluster, just outside the M24 star cloud. It also contains nebula, specifically gn 6589 and 6590.
oc Cr. 469: 2'.6; Vis. 9.1; 51 *s: Preceding ngc 6603, this was spotted at 60x as several bright stars in a tight V-shape, with background haze. At 100x it is very compact, with a few faint stars resolving. At 200x 15 stars show up, several being very faint. 51 stars?! In a 2.'6 area?! No way.
oc Cr 367: 40'; Vis. 6.4; 30 *s: Seen best at 43x using the 2" eyepiece, this is a lovely, very large group containing many bright stars as well as as all of the preceding faint gn (gn I 1274-75). Use low power and sweep.
oc Cr 371: 20'; Vis. mag. 7; 30 *s: At 60x and 100x, about 60 stars are counted. They are widely scattered and surround a bright yellow star. This is a nice cluster, just outside the M24 star cloud. It also contains nebula, specifically gn 6589 and 6590.
oc Cr. 469: 2'.6; Vis. 9.1; 51 *s: Preceding ngc 6603, this was spotted at 60x as several bright stars in a tight V-shape, with background haze. At 100x it is very compact, with a few faint stars resolving. At 200x 15 stars show up, several being very faint. 51 stars?! In a 2.'6 area?! No way.
oc Cz 37: 3'; 35 *s: A very small, insignificant group is revealed, mostly haze, south preceding a bright star. A few stars resolve.
oc E397-1: 6': I was able to star hop here from gc 6723. It was spotted at 100x, and already fairly interesting. 150x, 187x and 200x gave good views of a dozen or so scattered faint stars, immediately preceding a 9.5 mag. star. As the only open cluster on Uranometria Chart 163, left side, I simply had to seek it out.
oc E397-1: 6': I was able to star hop here from gc 6723. It was spotted at 100x, and already fairly interesting. 150x, 187x and 200x gave good views of a dozen or so scattered faint stars, immediately preceding a 9.5 mag. star. As the only open cluster on Uranometria Chart 163, left side, I simply had to seek it out.
gc E456-38: 9'.9; Vis. mag. 9.9: Appearing much smaller than its given size, it was more like a faint, round planetary nebula or galaxy as seen at 125x amidst a triangle of brighter stars. It was viewed with averted vision up to 200x, about 2' in size. Even in photos it appears smaller than nearby ngc 6520.
eg E460-30: 1'2 x 0'.8: Vis/SB Mag. 12.7: A near twin to nearby eg 6816, this small, faint spot was also picked off tonight, just north of the NGC object. Both objects fit into the same view, even at 187x.
oc E521-5: 4': Located at 100x, 3 brighter stars are noted. At 200x there are about 15 stars, mostly very faint.
oc E521-38: 3': This is a compact group of pretty bright stars, with 15 showing up at 125x.
oc E524-1: 6': Larger, richer and more scattered than nearby Ru 146, stars resolved at 100x and higher. It is a pretty good object at 150x, despite its -27 degree location.
oc E525-8: 5': At 200x a dozen stars mag. 13 and fainter can be seen. It was observed in a light polluted area of my south sky.
oc E589-26: 2'.5: At 150x a small, hazy patch is noted. 187x and 200x resolve a few stars. 250x shows 6-8 stars, some in a line. A challenge!
oc Mrk 38: 2': At 60x 3 bright stars were noticed right away, with 1 of them being very bright and yellow. At 200x ten stars are very close to the bright three, with a few others close by.
gc Pal 8: 5'.2; Vis. 10.9; Br. * mag. 15.4: A fun discovery, this faint, large and hazy globular cluster was seen at 43x through 250x. Resolution begins at 150x, with a few of the brighter outliers. 5 or 6 stars can be counted at 250x. Not a bad object.
eg E460-30: 1'2 x 0'.8: Vis/SB Mag. 12.7: A near twin to nearby eg 6816, this small, faint spot was also picked off tonight, just north of the NGC object. Both objects fit into the same view, even at 187x.
oc E521-5: 4': Located at 100x, 3 brighter stars are noted. At 200x there are about 15 stars, mostly very faint.
oc E521-38: 3': This is a compact group of pretty bright stars, with 15 showing up at 125x.
oc E524-1: 6': Larger, richer and more scattered than nearby Ru 146, stars resolved at 100x and higher. It is a pretty good object at 150x, despite its -27 degree location.
oc E525-8: 5': At 200x a dozen stars mag. 13 and fainter can be seen. It was observed in a light polluted area of my south sky.
oc E589-26: 2'.5: At 150x a small, hazy patch is noted. 187x and 200x resolve a few stars. 250x shows 6-8 stars, some in a line. A challenge!
oc Mrk 38: 2': At 60x 3 bright stars were noticed right away, with 1 of them being very bright and yellow. At 200x ten stars are very close to the bright three, with a few others close by.
gc Pal 8: 5'.2; Vis. 10.9; Br. * mag. 15.4: A fun discovery, this faint, large and hazy globular cluster was seen at 43x through 250x. Resolution begins at 150x, with a few of the brighter outliers. 5 or 6 stars can be counted at 250x. Not a bad object.
oc Ru 129: 4'; Br. * mag. 12; 10 *s: Located at 100x and resolving. At 200x I saw 10-12 stars, some very faint. Located north preceding a 9.5 mag. star.
oc Ru 131: 8'; Br. * mag. 11; 15 *s: An unimpressive group of faint stars surrounds one of mag. 9.7. While noted at 60x, I only managed to resolve 10 stars at 200x.
oc Ru 134: 5'; Br. * mag. 12; 30 *s: In my excellent sky tonight this was an impressive little cluster, even down at -29 degrees. Located at 60x immediately following a mag. 8 star, which in fact turned into a double at higher power. At 60x the group was pretty large, faint but resolving. 100x and 125x gave fine views. 200x showed 30+ stars, though they were very dim. The double is estimated to be 8-12/8".
oc Ru 136: 3'; Br. * mag. 13; 40 *s: Because of the proximity of two fairly bright stars, this group is not apparent as a cluster until 200x and 250x is applied. Most members are very faint, with a few slightly brighter members (mag. 13). There is some resolution (about 10 stars) and some haze.
oc Ru 137: 5'; Br. * mag. 13; 30 *s: Obvious at 100x, it was also observed at 150x and 200x. A small swarm of faint stars surround a mag. 8.5 star.
oc Ru 138: See write up for oc 6506, in Part 2 of Sagittarius objects.
oc Ru 139: 12'; Br. * mag. 12; 80 *s: 60x, 100x, and 120x give good views of this busy cluster, which is large and pretty scattered. Many brighter stars are interspersed with a lot of fainter ones.
oc Ru 140: 5'; Br. * mag. 11; 15 *s: Spotted at 60x, it was faint and hazy, but pretty large in size. 100x provides decent resolution. At 125x and 150x about 20 stars are resolved, most of them being similar magnitude. It is a circular group, and somewhat compact. 187x and 200x resolves a small knot of stars on the north following edge. Worth a look.
oc Ru 145: 35'; Br. * mag. 10: 43x shows a very large and rich group of stars. At 60x the object fills the eyepiece with stars. There is a denser, rich center, and the cluster includes many fine patterns. Numerous faint stars surround the central group. Definitely worth a stopover.
oc Ru 146: 4'; Br. * mag. 12; 20 *s: The cluster is small and compact, barely resolving at 100x and 125x. It becomes better at 150x, with about 15 stars resolving.
oc Ru 134: 5'; Br. * mag. 12; 30 *s: In my excellent sky tonight this was an impressive little cluster, even down at -29 degrees. Located at 60x immediately following a mag. 8 star, which in fact turned into a double at higher power. At 60x the group was pretty large, faint but resolving. 100x and 125x gave fine views. 200x showed 30+ stars, though they were very dim. The double is estimated to be 8-12/8".
oc Ru 136: 3'; Br. * mag. 13; 40 *s: Because of the proximity of two fairly bright stars, this group is not apparent as a cluster until 200x and 250x is applied. Most members are very faint, with a few slightly brighter members (mag. 13). There is some resolution (about 10 stars) and some haze.
oc Ru 137: 5'; Br. * mag. 13; 30 *s: Obvious at 100x, it was also observed at 150x and 200x. A small swarm of faint stars surround a mag. 8.5 star.
oc Ru 138: See write up for oc 6506, in Part 2 of Sagittarius objects.
oc Ru 139: 12'; Br. * mag. 12; 80 *s: 60x, 100x, and 120x give good views of this busy cluster, which is large and pretty scattered. Many brighter stars are interspersed with a lot of fainter ones.
oc Ru 140: 5'; Br. * mag. 11; 15 *s: Spotted at 60x, it was faint and hazy, but pretty large in size. 100x provides decent resolution. At 125x and 150x about 20 stars are resolved, most of them being similar magnitude. It is a circular group, and somewhat compact. 187x and 200x resolves a small knot of stars on the north following edge. Worth a look.
oc Ru 145: 35'; Br. * mag. 10: 43x shows a very large and rich group of stars. At 60x the object fills the eyepiece with stars. There is a denser, rich center, and the cluster includes many fine patterns. Numerous faint stars surround the central group. Definitely worth a stopover.
oc Ru 146: 4'; Br. * mag. 12; 20 *s: The cluster is small and compact, barely resolving at 100x and 125x. It becomes better at 150x, with about 15 stars resolving.
oc Ru 168: 4'; Br. * mag. 12; 20 *s: I star-hopped on this night, beginning at oc 6520 and finding 7 minor clusters in a very small area. This one is in two parts; the north area is very tight and dense, while the south half is looser. It follows a close pair of 8.5 mag. stars. Members are faint. At 200x I counted 20-25 stars, some barely resolving.
oc Ru 169: 3'; Br. * mag. 14; 10 *s: This one is located just south of Ru 136 and Ru 138. Both of those objects were seen to good advantage in tonight's superior sky. This one is a nice string of faint stars, thickest surrounding 2 11.5 mag. stars. Best seen at 200x.
oc Ru 171: 12'; Br. * mag. 14; 60*s: Located just north of 2 9 mag. stars in an east-west line. 100x will show the group, but it takes 150x and 187x to properly resolve it. Stopped down to 8" of aperture, resolution is poor, with haze. At full aperture, 200x resolves dozens of stars, including several dense sections that require averted vision. This is worth a stop with a 12" mirror.
oc Ru 169: 3'; Br. * mag. 14; 10 *s: This one is located just south of Ru 136 and Ru 138. Both of those objects were seen to good advantage in tonight's superior sky. This one is a nice string of faint stars, thickest surrounding 2 11.5 mag. stars. Best seen at 200x.
oc Ru 171: 12'; Br. * mag. 14; 60*s: Located just north of 2 9 mag. stars in an east-west line. 100x will show the group, but it takes 150x and 187x to properly resolve it. Stopped down to 8" of aperture, resolution is poor, with haze. At full aperture, 200x resolves dozens of stars, including several dense sections that require averted vision. This is worth a stop with a 12" mirror.
oc Tr 31: 5'; Vis. 9.8; 25 *s: This is a decent little cluster at 125x and higher. A triangle of stars has a faint cloud of tiny ones amidst them. 25 stars are easily counted at 200x.
oc Tr 33: 6'; Vis. mag. 7.8; Br. * mag. 9.7; 74 *s: A bright orange and blue double star lies in the preceding end, with the blue star being very faint. At 60x the cluster is mostly haze in behind a line of 3 bright stars. The haze is resolving at 100x. At 125x and 150x many faint stars are resolved, along with 9 or 10 brighter ones. About 35 stars were counted at 187x and 200x. A nice minor cluster.
oc Tr 33: 6'; Vis. mag. 7.8; Br. * mag. 9.7; 74 *s: A bright orange and blue double star lies in the preceding end, with the blue star being very faint. At 60x the cluster is mostly haze in behind a line of 3 bright stars. The haze is resolving at 100x. At 125x and 150x many faint stars are resolved, along with 9 or 10 brighter ones. About 35 stars were counted at 187x and 200x. A nice minor cluster.
oc vdB-Ha 245: 1'; 12 *s: Located at 200x, south preceding a mag. 8 star. Several faint stars are resolved.
That about does it for Sagittarius, a project that I worked on during summer and fall of 2014 and 2015. Next summer I will continue working in Lacerta and Hercules, and then in Pegasus during the autumn. My Winter project is Taurus, and in Spring it will be back to Leo and Bootes. Hoping for many clear nights ahead!
Mapman Mike
Mapman Mike
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