Deep sky observing report - 2008 Oct 25

posted: 3195 days ago, on Saturday, 2008 Oct 25 at 09:32
tags: astronomy, deep sky, observing report, Stellenbosch.

With all the hecticness of Astronomy Month, I haven't had a chance to check out the 8-inch Dobsonian (christened "Maphefo") under deep sky observing conditions. A bright sunny Saturday gave way to a clear evening, and by night fall I was set up in the vineyards.

The sky looked OK, although the northern horizon faces Stellenbosch and suffers from light pollution. Jupiter was soft, its bright disk making prominent diffraction spikes from the spider, something I'd noticed during the public evenings.

The Lagoon was pleasant as always, the cluster/nebula combination striking.

I swept on to NGC 6544, one of the stranger globular clusters. With a variety of eyepieces (from 40x to 120x) it is noticeable how a number of faint field stars, scattered around near the cluster, make it appear like quite a large object (the brightest of these lie to the west (one star) and to the east (3 stars)). Only on a second look is it clear that the actual object here, a moderately faint glow, is separate from these stars. Remarkably, the shape of the globular is quite unclear it is irregular and not round like one would expect and looks more like a nebula. At times, a single pinprick of light seems to shine within the nebulosity.

A short distance away is NGC 6553, a moderately bright object, round, pretty evenly illuminated and not noticeably brighter to the middle. A small star (V=11.1) is embedded in its north-western extreme. It appears to be about twice the size of its neighbour, NGC 6544. Two 10th mag stars to the south-east have the same separation as the globular's diameter (about 2.5 arcminutes).

I checked up on Jupiter again, and to my delight saw Io emerge at Jupiter's western edge, almost in line with the planet's northern belt. And I could swear I saw some detail or sharp area (or shadow?!) central on the northern belt. Active imagination, indeed.

Finally, I turned to the Small Magellanic Cloud and started to plot objects on a specially prepared chart from which all deep sky objects had been removed. It's much nicer finding these things yourself, than hopping from object to object as is the custom. I'd only recorded eight finds when a combination of eye fatigue and itinerant thin cloud drew the night's activities to a close.

Not a great night. But not a bad one, either.

nothing more to see. please move along.