Sky and Telescope - July 2015 - 57

Sue French

Sue French welcomes your comments at scfrench@nycap.rr.com.

13½′ × 8′. B93 is an 8′ ×3′ band with a less pronounced
extension bending southward from its southwestern
end. This eye seems to be winking. Collinder 469 is a
little knot of stars just a few arcminutes oﬀ the extension's end. A very long and distinctive line of faint stars
sweeps east-northeast to west-southwest across M24.
The star chain skims north of B92 and B93, and it has a
northward bump between them.
The open cluster NGC 6603 is a nicely obvious patch
of haze ﬂecked with a few superimposed stars. It's
perched near a red-orange star, which is the middle star
in the northern arm of a 20′ V of 7th- and 8th-magnitude
stars. The middle star in the southern arm of the V is the
double SHJ 264 (S,h 264). Its whitish components are
well separated, with the 7.6-magnitude companion 17″
northeast of its 6.9-magnitude primary. The pair's designation tells us that it's the 264th entry in James South's
and John Herschel's multiple star catalog of 1824.
Although I can't ﬁt all of M24 in the ﬁeld of view at
63×, it's amazing how much more obvious and intricate
the dark nebulae are at this magniﬁcation. A fairly conspicuous thread runs east-northeast from B93, leading to a
large area of patchy darkness that contains Barnard 307.
Much dark nebulosity spreads west from B92, and a long,
forked patch (Barnard 304) reaches southwest. Collinder
469 and NGC 6603 share a ﬁeld of view. Cr 469 shows six
stars that form a capital A pointing northeast, while pretty

NGC 6603 is a granular patch of mist. At 117×, Cr 469 displays 11 stars in a group whose longest dimension is about
3¼′. A bit larger but much more crowded, NGC 6603 is
sprinkled with many faint to very faint stars over haze. It
sports a prominent southeast-northwest band of stars that
cuts across the cluster's center.
NGC 6603 is wonderfully transformed by the 10-inch
scope. At 213×, it's a beautiful cluster of myriad diamond-dust stars, with little unresolved haze remaining.
You might think that M24 would be a terrible place
to look for a petite planetary nebula, but I was surprised
to ﬁnd NGC 6567 reasonably easy to spot through my
130-mm scope. At 37× it appears bluish and minuscule,
but most deﬁnitely not stellar. A magniﬁcation of 117×
reveals a tiny blue-grey disk that's fairly bright. A dim
star sits just oﬀ the nebula's eastern side. At 205× the
nebula seems to have a brighter center.
Through my 10-inch reﬂector at 115×, NGC 6567
presents a strikingly blue-green disk that I judge to be
about 9″ across.
A few other star groups from Charles Messier's
famous 18th-century catalog keep M24 company. Its
nearest neighbor on the sky is the open cluster Messier
18, which hovers over (north of) the star cloud's northeastern end. My 130-mm refractor at 48× shows 15
moderately bright to faint stars, most arranged in a cute
shape resembling a slightly mangled hairpin. At 91× I

M24 Small Sagittarius Star Cloud

M20

B307
M17

NGC 6603

IC 4685
NGC 6589
NGC 6595
IC 1284
JASON JENNINGS

M16

B304
B92
Cr 469
B93

Sk yandTelescope.com July 2015

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Sky and Telescope - July 2015

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