Andrew’s Astronomy Blog

Saturn is back in the evening sky. Having shot some three colour video sequences of Mars on the Celestron 9.25 I switched to Saturn which was just rising out of the murk at about 20 degrees elevation. The rings are just beginning to open out after last year’s edge on aspect and with the planet higher in the sky as it approaches opposition it should be favourable for imaging.

1500 frames each of red, green and blue video were stacked and combined for this image.

AstroFest saw me treating myself to something I’ve wanted for some time, an AstroTrac. Sunday evening was clear and frosty so I set the unit up on the top of a tripod on the path in front of my house. Leaving the Canon kit 18-55 lens on the 350D I took 10 3 minute exposures of Cassiopia at ISO 400 with the lens set at about 40mm. This produces a huge field of view that takes in the whole constellation down to the Double Cluster in Perseus (lower left of frame) and across to NCG 7789 (mid right).

This type of photograph is very demanding on the lens and the Canon zoom fares badly with lots of chromatic aberration. Looks like I’ll have to invest in some better quality fixed focus lenses.

Once the cloud departed on Friday evening we were left with a pretty clear and still evening. Syrtis Major on Mars was clearly defined in the eyepiece of the club Celestron 9.25 so I attached a filter wheel with webcam and Astro Engineering x4 ImageMate for some pictures. All the videos were about 2000 frames long at 10fps and about half the frames were rejected during processing.

At about 14 arc-seconds diameter Mars is now receding from us.