Archives for December 2025

Telescope: 1959 Vintage 40mm f/17.5 Unitron 127 Refractor

Camera: ZWO ASI294MC, GSO IR Filter

Exposure: 350×5msec, Gain 200, saved as SER

Seeing: Fair, 3/5

Software: SharpCap Pro, Autostakkert, Nebulosity, Registax, Photoshop

It was bitterly cold tonight, but I could resist trying to grab a picture of the gorgeous full Cold Moon. I needed something super simple and up to the task, so I grabbed my trusty old vintage 40mm f/17.5 Unitron 127 and added a ZWO ASI294MC camera using a 1.25” to 0.965” adapter. I made a simple modified Hartmann mask from a piece of aluminum foil and set the focus using Capella. I ythen moved over to the moon and grabbed a couple of SER image sets using Sharpcap Pro. While I had the scope out I swapped out the camera for a stock Unitron star diagonal and a 18mm Kelner eyepiece to take a peek at the moon and Jupiter. The moon looked fabulous and Jupiter looked classic showing all four Galilean moons, equatorial bands, and dark polar regions. Despite a set of frozen fingers, it was a lot of fun!

In a manner similar to what I showed previously with Uranus, this is a composite of 4 images taken with a Seestar S50 to see if I could observe some of the outer moons of Saturn. The source images were taken on 11/12 (19h52m), 11/13 (19h19m), 11/14 (21h04m) and 11/16 (20h19m), EST. Each source image was 30x10sec centered on Saturn using the Seestar Stargazing mode. The star fields of each image were first aligned to given them a common field orientation, and then they were aligned on Saturn. Blinking the fields allowed me to discriminate between the moons and stars. I kept the stars in the first field (11/12), carefully removed the stars from the other fields, and then merged them into a single, flat image. The bright inner moons are easy to see as they lie in a nearly straight line. These include Dione (Mv 10.5), Rhea (Mv 9.8), and Titan (Mv 8.4). These orbit Saturn so quickly it’s hard to follow them with overlaid as shown here and there are multiple images of each. Mimas, Enceladus and Tethys are hiding in the glare of Saturn. In line with the inner moons and to the lower left is the more distant moon Hyperon (Mv 14.3). On close examination there are 4 images of Hyperon, but on the first 3 evenings it passed through greatest eastern elongation and 2 of the images are nearly on top of each other. Off to the right is Iapetus which moved from upper left to lower right during this sequence. Iapetus varies in brightness from Mv 10.2 at greatest western elongation to 11.9 at greatest eastern elongation and at the time these images were taken it was near the brighter node. I’d like to see if I can follow Iapetus all the way around its 79 day orbit, but that may have to wait until next year.

Neat Stuff.