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RA: 19h 01m 18s
Dec: +11° 37′ 0″
Ch: MSA:1245, U2:206, SA:16
Ref: SIMBAD, Collinder (1931), DAML02, Archinal&Hynes (2003)
Type: open cluster, 42p
Mag: B=?, V=8.3
NGC 6738, found by JH, is an optical alignment of a couple of dozen bright stars seen through varying amounts of dust. It is not a real cluster. Boeche et al (A&A, XXX, XXX, 2003) have done a thorough photometric, astrometric, and spectroscopic study of the field and have not been able to find a real cluster here. There are undoubtedly many other such clusters in the catalogues.
The RNGC (Sulentic and Tifft 1973) notes that this is a 8.0 mag open cluster.
Phil Harrington (1990, Touring the Universe through Binoculars) notes that it is similar in appearance to NGC 6709, and that "once located, it reveals only a few of its brighter stars, which are about 9th mag. Larger glasses should have little trouble yielding a glimpse of these stars, and even 7x binoculars show a few of them set within the glow cast by fainter luminaries."
8x50mm - not obvious. BS, 3Sep1981, Anderson Mesa.
15cm - mod br widespread cl w/string of brtr *s running N-S through it. 30'
diam, 95x shows 45 *s. in brtst part *s have wide range of mags. on E
side is elong strip of m12.5-13 *s (~dozen). BS, 3Sep1981, Anderson Mesa.
- scattered and little concen grp among br & dk areas (dk 30' W, vf *clouds
45' S). outline seems triangular due to br overlying *s, esp string of
m8-10 *s along and beyond E base (plotted on U2000). 140x shows 65 *s in
15' irreg round area. not a terribly interesting obj. BS, 2Jul1989,
25cm - 75 *s incl batch on E. not outstanding in Milky Way. BS, 3Sep1981,
Steve Coe, using a 13" f/5.6, notes: "Large, pretty bright, irregular shape at 100X. 20 members of magnitudes 9 to 10, another 20 members with magnitudes less than 13. Looks like a cluster with a step function magnitude distribution. I have rarely seen a star cluster that does not seem to gradually fade to dimmer members."
Karoo Star Party, Britstown, Northern Cape, ZA.
15x70 Celestron binoculars.
Two moderately bright stars involved in an approximately oval haze, 6' across. Not prominent.
16-inch f/10 SCT (127x 290x)
This is a special group that displays it stars from the brightest to the faintest in a formation of a long hock in south-north direction. Very fascinating.
The Messier objects
The Bennett objects
The Caldwell list
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