Equipment Report
An Astrotrac mount ship, with polar scope, has been acquired from a trader in the UK galaxy. The price was reasonable, and the item is in pretty good visual condition, specially when one thinks the mount ship may be around 10 Terran years old.
In order to test it, the engineers mounted it on top of the mount ship CG5 and its tripod (we could have used a lighter setup, they told me, but we lack an equatorial wedge), then we aligned it using the polar scope of the Astrotrac itself. This scope has three reference stars, of which we used two - we are not sure we got the second one right, though. Finally, I ordered a jump, and images of increasing exposure were recorded.
At the edges of the images, stars trail in all exposures; at the center, they are quite round up to 60s, slightly elongated at 120s, and clearly elongated at 180s and longer. Our exposures are usually no longer than 40s; up to that length, the new mount seems to perform similarly; beyond that length, we only have a couple of images (from a drift alignment test), so conclusions cannot be reached yet, however we can say that Astrotrac's are better than those.
Astrotrac images focused around 7 Ari, with image center at ra,dec (1h55m, 24º), alt/az (85º, 32º); while drift alignment images focused around m45, with image center at ra,dec (3h48m, 24º), alt/az (77º, 23º) - taken just a few days apart. Astrotrac (left edge, then center) first, drift aligned (on CG5) after. All at 300% magnification.
In conclusion, this Astrotrac makes for a light mount ship of good performance, with limitations: 2h max jumps, no remote control, no weights balancing as-is... For the moment being, we will keep it, but we may as well trade it in the future if we can make a profit.
In order to test it, the engineers mounted it on top of the mount ship CG5 and its tripod (we could have used a lighter setup, they told me, but we lack an equatorial wedge), then we aligned it using the polar scope of the Astrotrac itself. This scope has three reference stars, of which we used two - we are not sure we got the second one right, though. Finally, I ordered a jump, and images of increasing exposure were recorded.
At the edges of the images, stars trail in all exposures; at the center, they are quite round up to 60s, slightly elongated at 120s, and clearly elongated at 180s and longer. Our exposures are usually no longer than 40s; up to that length, the new mount seems to perform similarly; beyond that length, we only have a couple of images (from a drift alignment test), so conclusions cannot be reached yet, however we can say that Astrotrac's are better than those.
Astrotrac images focused around 7 Ari, with image center at ra,dec (1h55m, 24º), alt/az (85º, 32º); while drift alignment images focused around m45, with image center at ra,dec (3h48m, 24º), alt/az (77º, 23º) - taken just a few days apart. Astrotrac (left edge, then center) first, drift aligned (on CG5) after. All at 300% magnification.
In conclusion, this Astrotrac makes for a light mount ship of good performance, with limitations: 2h max jumps, no remote control, no weights balancing as-is... For the moment being, we will keep it, but we may as well trade it in the future if we can make a profit.
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