Map 21: South Equatorial 6
Sagittarius to Sculptor
August 22, 2007
The last of the mid-southern star maps features most of Capricornus the Sea Goat, Microscopium the Microscope, Piscis Austrinus the Southern Fish, and Grus the Crane — the only star figure in this region that resembles its namesake. We've also passed the Milky Way, so many more galaxies appear to populate this region.
Microscopium houses several galaxies that will test your observing prowess through an 8-inch telescope. Look for IC 5039. At magnitude 12.6, this object won't blind you, but it's noteworthy because of its interaction with IC 5041, a similarly bright galaxy located only 10' to the north-northeast. IC 5039 appears large with a broad core, while IC 5041's central region is more concentrated.
Move 3° southwest of the galactic pair and you'll find NGC 6925, a magnitude 11.3 spiral galaxy that appears 3 times as long as wide. With a 12-inch scope, you can pick out the irregularly illuminated halo surrounding the moderately bright central region. The core appears stellar.
At magnitude 11.3, NGC 6958 and NGC 6925 are the brightest galaxies in Microscopium. NGC 6958 measures 2.5' by 2' with a core slightly brighter than its outer regions. NGC 6958 marks the eastern corner of an equilateral triangle 3' on a side. Two 10th-magnitude stars sit at the other corners.
In Grus, several spiral galaxies are worth a look. Center Alpha Gruis in your eyepiece's field of view. Only 16' to the southeast lies NGC 7213. Luckily, this 10th-magnitude galaxy is bright with a prominent core. NGC 7213 measures 4.8' by 4.2'.
Next, find the Grus Quartet, the brightest member of which is NGC 7582. This galaxy glows at magnitude 10.6 and measures 6.9' by 2.6'. Two other members of the quartet are NGC 7590 (magnitude 11.5) and NGC 7599 (magnitude 11.4). These galaxies, which have similar shapes and sizes to NGC 7582, lie 10' to the northeast. The last member, magnitude 10.7 NGC 7552, sits 1/2° southwest of NGC 7582.
Magnitude 10.9 NGC 7314 sits about 1° northwest of Epsilon Piscis Austrini. This spiral galaxy measures 4.2' by 1.7' and is oriented north-south. Smaller, fainter NGC 7313 lies only 5' west of NGC 7314, just off the southern tip of the brighter galaxy's outer region.
If you'd like a change from galaxy observing, move into eastern Capricornus and locate globular cluster M30. This magnitude 6.9 object measures 11' across. Its core is concentrated, and its outer regions appear irregular through 6-inch and larger telescopes. Through a 10-inch scope at 200x, you'll count 200 stars.
If your telescope measures 16 inches or larger, try for the NGC 7103 galaxy group, 1° north of M30. NGC 7103 is the brightest member, and it glows at a magnitude of only 12.6. The others are fainter. Don't expect to see detail in these objects — it's a victory just to spot them.
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