Getting my Unitron Model 114 out under dark skies prompted me to get out the Unitron Model 510 (127mm,
f/16) photo equatorial. This model comes with a whole set of accessories including camera, Unihex (rotary eyepiece holder), 60mm guide scope, solar projection screens, electric drive motor and counterweights. Fully dressed it weighs in at 275 lbs! This particular Model510 was originally donated in the 1960's by Unitron to a school in Texas, but subsequently changed owners four times. I've had the scope since 2015, and use it for observing several times a year. I've also taken it to NEAF on three occasions. This photo dates back to NEAF 2015.
For observing sessions, I use it mostly "unaccessorized" and on a Losmandy G-11 mount with 12 inch pier extension. Last evening's session was focused on the Moon...although I planned to take in several double stars as well. The original eyepieces were all .965" except for a unique 2" 60mm. I used my set of TV
EP's including: 22mm Panoptic (91x), 10mm Radian (200x), 6mm Ethos (333x), and a 3.7mm Ethos (540x).
The Moon was about 60% illuminated and presented some interesting features along the terminator. I began by exploring the terminator from North to South using the 22mm Panoptic and then the 10mm Radian. Views were "sharp and contrasty" throughout and improved as the sky darkened. In the western region of Mare Imbruim the Alps Mountains and Alpine Valley shone beautifully as well as Mts Pico and Piton. I completed my initial "low power" survey checking out craters Parry and Guericke, then Pitatus, Tycho, and along the way took some long looks at the "Straight Wall".
I then upped the magnification using first the 6mm Ethos and then the 3.7mm Ethos on selected features including the Alphine Valley, the Apennine Mts, the Straight Wall, and Tycho. Even at 540x, features displayed crisp and with excellent contrast. By this time the Moon was almost overhead and even with the 12 inch pier extension, the
EP was getting too low for my aging back!!
I completed the session observing several doubles including: Algieba, Porrima, and Zeta Cancri (which at about 1 arc sec split nicely at 200x).
Till next time...
Dave
