Solar system hat trick


Well last night turned out to be pretty good unexpectedly. But first.

Without really intending to I pulled off, thanks to a bit of daytime astronomy courtesy of Mr. Blackwell, the tour de to speak. I dropped by Kents to set up my telescope in the afternoon before it got dark and found him in the back yard, demonstrating he had no life by doing daytime astronomy. We looked at Mercury and Venus in his 4 inch TMB. Venus was easy to see about 10 degrees from the sun. It is full so the size is at it's minimum but it stood out in the daytime sky. Mercury is much smaller. Once you find it the planet is easy enough to see but you could lose it in the fov.

 Later in the evening around 5 to 6 I was trying out my new (used) 5mm ortho circle T eyepiece. I quickly observed Saturn now going low in the west and Jupiter near the meridian. I forgot about that as the night wore on and went to several doubles to further test the eyepiece. Later I stopped in at Neptune which has been no great shakes this year, or ever and then a bit later got in Uranus which is more interesting as it is easily seen as a greenish blue disc. It them occurred to me I had completed the tour of the solar system planets somewhat unintentionally. Counted them on my fingers..............yup all accounted for.

We visited several very nice doubles in the course of the evening. All this was to  test out an old school Orion 5mm orthoscopic eye piece. I acquired this on astromart the other day for $50.00. It is an old "Circle T" orthoscopic eye piece. Volcano topped as they were called, the circle T were marketed by several companies way back when. They were built by one man in Japan, Mr. Tani. They have limited eye relief and narrow fields of view compared to modern multiple glass wide field eyepieces but have fine detail and contrast coming out of the eyeballs. They were a simpler design that have dead black backgrounds against bright planets. They also can show very fine details on planets and the moon that the modern wide fov occular, good as they are, just cannot do. We put it in Kent's 6 inch on Jupiter and it was superb. Far superior contrast to the Pentax eyepieces. That 6 inch telescope is the best planet scope I have seen. The detail is just amazing. The 5mm performed flawlessly in it. In my scope the color transmission and resolution is excellent. Color easily seen in double stars, even small ones. Perfect dots on black background. These eyepieces can be found on the used market with some effort. The 5mm size is quite rare and works perfectly in my long focus refractors. Eye relief is not too bad at 5mm, though tight by modern standards. Anything less than 5mm becomes a bit harder. The barrel does not have that obnoxious undercut and is made quite solid. The term volcano top comes from the raised shape of the upper surface of the eyepiece. These are planet/lunar killers. Not so good for deep sky due to limited fov. They were designed to be best in longer focal ratios of F7 to F15. They may not be so happy in faster telescopes. Having an F7 and an F10 refractor they are the bomb. The only other eyepiece that can beat then is Kent's 10mm Gailand. These are rarer than woodpecker lips and instantly disappear when they come on the used market. Against a full moon it has a dead black background. These are very hard to come by. We almost got one the other day but it was bought instantly as soon as it came on the market.

Oh, I forgot Mars. We used the 5mm on Mars later in the evening. What a great view. Very good in the 5 inch and astounding in the 6 inch. Maybe the best view of Mars I have seen in 50+ years of observing. It was jaw dropping. We used a magenta # 30 filter to highlight detail. That is a very good shade for Mars helping contrast  an keeping the subtle poles visible. Much better than the red or orange filters. Vernonscope of course.

Quit about 10 as everything was drenched by that point.

Ian Stewart

Great write-up Mark. Cloudy all night here as its been for the past four days ... Cheers Ian