by Jay Reynolds Freeman
Many northern amateurs do not know where the southern constellations are and how they fit together. Crux is about the size of Corvus, and lies south of it by a bit more than the width of two handspans, with fingers stretched apart, at arm's length. Huge Centaurus envelopes Crux to the west, east, and north: Maps with pictures for the constellations show the Southern Cross as road kill under the Centaur's great hooves.
With Crux on the meridian, Carina and Vela are off to its right. The eta Carina complex sits a handspan out. Brilliant alpha and beta Centauri lie a handspan left of Crux, and dominate the sky there.
Above left of Centaurus is the motley strew of bright stars that define Lupus, the wolf. A sliver of Circinus fits just east of Alpha Centauri. East of that lies nondescript Norma, well south of Antares. Then comes Ara -- beta, gamma, and zeta Arae form a prominent, long, narrow triangle, pointing west, below the fishhook of Scorpius by about the width of a fist at arm's length. The whole constellation is much larger.
Telescopium is next, with few bright stars. It begins below Corona Australis, which in turn lies below the teapot of Sagittarius, and ends south of the west end of Capricornus. Beside its southeastern corner shines bright alpha Pavonis, the Peacock Star, drawing emphasis and dramatic enhancement from its solitude, like Fomalhaut. Pavo extends far south from Telescopium.
Indus is east of Telescopium. Alpha Indi is fairly bright, a third of the way from alpha Pavonis to southern Capricornus, south of Microscopium. East of Indus lies southern Grus, and that is as far as my survey went.
A few more southerly constellations peeped over Mauna Loa during my evenings in Hawaii. I saw objects in Musca, south and east of Crux, and in Triangulum Australe, south of Norma. But on the third night of my expedition, I observed many objects that were comfortably above the south horizon; I had logged enough of those that were about to set, that I did not have to spend all my time scrambling after them.
I reviewed omega Centauri in the ten-inch. It was just as wonderful as it had been in the Visitor Center's C-14, showing many resolved stars against a granular background. Further north, I checked NGC 5128, the Centaurus A radio source. This mysterious galaxy well showed the broad, dark band that crosses it. I could begin to see feathery detail or scalloping at the band's edges. But my best views of this object had been with larger telescopes at mainland sites, so I moved on.
NGC 4945 lies about four degrees west of omega Centauri, in the middle of a triangle formed by xi-1, xi-2, and f Centauri. It is just a bit too far south to observe conveniently from central California. This galaxy is luminous and large -- some 20 by 4 arc-minutes in size, with a photographic magnitude in the mid 9s. At 106x it appeared essentially featureless, just a smooth smear of low surface brightness across the eyepiece field. I had hoped for something as rich in detail as NGC 3109 in Hydra, but no such luck. The same page of Millennium Star Atlas shows many field galaxies, from the NGC, IC, and ESO catalogs, and since I was in the neighborhood, I spent a while chasing them. Particularly challenging were NGC 4945A and ESO 219-14, both small, and both hiding in the glare of closely adjacent 9th magnitude stars. The 10-inch seemed almost as capable with faint fuzzies as Harvey, my Celestron 14. Some of its ability no doubt stemmed from the dark and transparent sky of Mauna Kea, but perhaps it is time to have my C-14 recoated.
Omega Centauri itself has many field galaxies nearby. They were easy to find: When I got lost, it was the work of a moment to sweep back to the giant globular and resume star hopping from it. One of these galaxies, ESO 270-17, is a high aspect-ratio edge-on, which is also called the Fourcade-Figueroa Object. A ragged line of tenth-magnitude foreground stars is superimposed on its long streak.
About seven degrees east of omega Centauri is a pretty small open cluster, NGC 5460, which contains two clumps of stars separated north/south. A degree and a half beyond it, almost to the Lupus border, is a small but relatively high surface-brightness NGC galaxy, NGC 5516, nearly superimposed upon ESO 221-34A, a larger galaxy with much lower surface brightness. I doubt I would have noticed the second galaxy if it had not been marked on my charts.
I looked at a few planetary nebulae in Centaurus, as well. NGC 3918, the Blue Planetary, was indeed blue. Notes in Burnham suggest it is rather like Uranus, but I might have said Neptune on grounds of color, and a bloated Neptune at that, for this object is much larger in angular size than either planet. I didn't see any detail at 106x.
PK 290+7.1 was oval, with a brightening at the center which made me note "central star suspected". Yet Steven Hynes's excellent book, Planetary Nebula (Willmann-Bell, 1991) does not list one, so I was presumably seeing a structural feature of the nebulosity itself. I should have put on some more magnification, but I was lazy.
I took a break from observing southerly targets to view a few more Messier objects, then resumed my program, starting to working eastward as the night progressed. But I was beginning to think about strategy for the rest of the week. I had a good many things to look at that would not be well placed until shortly before dawn, and to stay wide awake and efficient for an all-nighter might require catching up on sleep in advance. So I quit early, not long after midnight, with only 110 objects logged for the evening. Tomorrow would be a busy night.