Posts Made By: Ron Bee

http://members.cox.net/ronby/Observations/Fateful-Starparty.htm

Ron B[ee]

I'm sorry I'm full of questions this week (or perhaps full
of s__t :-().

I've been testing this new gadget someone on the Tele Vue eGroup has built for me, a Focus Lever that slip onto my focuser which allows me to focus without or little shake and act as a fine focuser due to the lever and virtually enlarging the knob.

First of all, let me define dark black "gap" as a dark thick line that has a detectable **width**. The Cassini Division was as clearly shown in Roland Christen's sketch from his 10" AP MCT as (quite a) large **gap**.

Anyway, I've been wanting to try out Jeff Medkeff's article on high magnification but found focusing a real pain until now. And I've been trying to find out about the Cassini Division; for up until last night, I've seen it as a dark line with no width.
http://roboticobservatory.com/jeff/observing/why_high_power.htm
So tonight at 293x, the Cassini Division appeared so sharp. Uping the ante to 352x and at 440x I believe I could see the division as dark thick line (like a very small gap) around the ansae. Oh, seeing was steady tonight. But at 110X/inch, I'm very cautious and am not sure if this is possible or am I just seeing diffraction effect. I think I haven't seen this before because I could never got it
focus properly due to the shake and lack of fine focusing at this high magnification. I now regretted I didn't have time to do a sketch last night :-(.

My question is: can the Cassini Division be resolved into a *small* gap with a 4" aperture? Or was I just seeing larger "airy disc"? If the answer is neah and yeah, then what is the **minimum** officially accepted aperture that could resolve the division into a **small** but detectable gap (just large enough without having it being so wide as to be able to drive a truck through that it ;-).

Thanks,
Ron B[ee]

While reading a pointer to the free ALPO (it's very big), I found another older free ALPO (Jan. 2000)
http://www.justfurfun.org/djalpo/DJALPO42-1-free.PDF
As I was reading, I came across this sentence on page 30.
"Note, however, that observers using smaller apertures of the order of 10.2cm (4.0 in.) can still contribute useful work on Saturn." What a music to my 102mm TV-102's focuser looking ears! Wow, I had no idea; I thought ALPO accepts only contributions from huge apertures (or at the very least a 6-inch).

Ron the 4-inch Tall Evangelist B[ee]

http://members.cox.net/ronby/Photos/Binoviewer.jpg

Ron B[ee]

Has anyone seen Mimas? Apparently, its magnitude is around 12.7 to 12.9 and revolves really close to Saturn (approx. 28 arcsec at its farthest distance from the ring according to my TheSky software). If you have seen it, which aperture did you use and did you have to wait until the ring was edged on?

Here's an article that I found.
http://www.njaa.org/current/astronotes/01/0203.html
However, since this article claims to require a 6-inch scope to view Enceladus, of which was bagged by my 4" TV-102 APO, I wonder how accurate the requirement this articles stated actually is in reality.

I believe Mimas might make a good practice observation prior to attempting Demos and Phoebos later this year. What do you guys think?

Thanks,
Ron B[ee]

Well, I finally got an appt. with Bill Larsen, one of the owner of Discovery to go look at the PDHQ models in 8" f/6, f/7 and 10" f/6 'cause I wasn't sure which one. I drove over an hour to Discovery in Oceanside, CA. I had expected a large factory filled with hundreds of people spitting out Discovery Dobs in an assembly line. What awaits me was a very small front office with the factory area in the back. Bill's partner Terry told me that there are only 11 people
(probably only 9 actually doing the work), amazing! Bill is a really nice, low keyed soft spoken kind of guy, inspiring trust. He brought out the base first, then the 10" f/6 tube. One look and I was unhooked ;-). I had to pinch myself to make sure I didn't sleep walk to an armory store instead of an astronomy store! The thing is a monstrocity, standing the same height as I am! One look and I told
Bill he can take it back ;-). Scary? You bet! Next, he brought out the tubes for the 8" f/6 and f/7. BTW, I saw the 24" mirror assembly for a truss Dobs in the office area on the floor and my, my, the thing looks like a small hot tub!

So it's between the 8" f/6 and f/7. The f/7 was slightly and I really mean slightly shorter than the 10". So that was no brainer. It's a quick 8" f/6 decision. It's just the right **maximum** size. The secondary is indeed a very small (looks like 19% obstruction is right). I can even imagine mounting the tube on a traditional EQ mount ;-). One thing that really stood out was the Crayford focuser
with the aluminum knob (with 3 holes) looking very similar to the ones on my TV-102 ;-). The base is a nice, varnished plywood (not like those particle board Chinese Dobs). Unfortunately at $799 it was not Honduras mahogany or New England maple wood that I prefer ;-). The OTA has a nice handle for carrying. The whole experience was hammering in. Seeing all 3 side-by-side was very eye opening!

I was told by Terry that Discovery doesn't really have a showroom; so the fact that Bill spent 1/2 hour from his very busy schedule is much appreciated. Out came the plastic. Thus, I really came away with a strong impression that buying a *premium* Discovery PDHQ is buying a custom made Dobs!

I don't know if I'll turn into Ron Dobster and may even turn into Ron Schmidt or Ron Maksutov some day. But for now, this will give me some idea of **using** a reflector. Who knows, I may eventually turn permanently and exclusively into Ron APO ;-). I do know this: the 10" Dobs ain't for me ;-) and I couldn't care less to see more with more aperture!

Ron the not quite yet 8" Tall Evangelist B[ee]

Well, my 4" TV-102 Light Cup is constantly looking for a new way to grow its midget aperture. Having failed at plastic lens design and biological based lens, its aspiration as a budding, albeit illiterate optical dis-signer ;-), came up with this latest innovative telescope
design!
http://members.cox.net/ronby/Photos/Cassefractor.jpg

Although the cartoon mixed in some humor, the fact that the design was drawn on an engineering paper surely suggests the seriousness of this post! What do you guys think? Why hasn't such a design been thought of? Is it possible? If so, it would make an 8" APO extremely portable and hopefully cost a lot less ;-).

Ron B[ee]

http://homepage.ntlworld.com/dpeach78/seeing2002.htm
An exuburlently excellent paper, IMO!

Well, I'm luck enough to be on Site A. Anyone on Site B would care to share their planetary experience?

Thanks,
Ron B[ee]

Seems like ages since my 4" TV-102 Light Cup and I spent time together in the evening :-( due to foul weathers and foul work schedule :-(. Wanting to do some laid-back observation (i.e. no sketch, no notes), I was planning on reporting something like: "I went out, I saw the Moon and I came in" ;-).

After the scope has cooled down tonight, I noticed at 9pm PDT how unusually steady the moon's rim was at 146x (6mm Radian) and was "rock circular" (not wavely like a mirage when the seeing wasn't excellent). I quickly ran upstairs to get the pictures of Plato and Alpine Valley. Let's refer to this picture for reference.
www.space.edu/moon/other/plato/PlatoChanges.html
Craterlet 1 was easy with depth (so I believe it was (esolved) at 146x. Craterlet 3 and 5 needed some more power. So I thought I would try something I've never tried before. I slipped on #12 yellow filter. What do you know; surprise - the contrast was substantially increased. I went directly to 293x (3mm Radian) and 3 and 5 were well
resolved and separated. Going back down to 176x (5mm Tak LE) resulted in resoluion as well (but both were really closed together though. Back down to 146x (still with #12 filter on), incredibly the Light Cup showed me craterlet 6. It was very difficult and I had to spend a lot of time and really looked in the area for the next 20-30 minutes, in which I saw it 2 more times. It looked like a tiny unresolved dot that appeared and then disappeared for a long time. I also tried to look for craterlet 8, but nothing :-(. The little "mound" near craterlet 8 as shown in the photo was clearly seen however. BTW, I tried the #80A blue filter and didn't really like it.

Next we moved to Alpine Valley looking for the Light Cup's holy grail: the Alpine Valley Rille. Seeing has worsen slightly as the rim now turned to wave slightly. I tried 146x, 176x, 293x with and without #12 filter (with #12 filter was much better). Nothing, no rille :-(. Getting really steamed up now, my Light Cup suggested why not look
for something of similar size and width? Umm ok, using Legault's image,
http://perso.club-internet.fr/legault/alpinevalley_w.html
I selected the "top" ridge (near the center of the photo) which has a cut in it. Well, this was seen at 146x (and #12 filter) with relative ease. Thus, for the first time since my Light Cup and I tried to find the Alpine Valley Rille, there is hope for seeing the widest part of the Rille. What do you guys think? All in all, I spent 1/2 hour strolling in the valley ;-).

What a great seeing night and a night of (lunar filter) discovery. Does anyone use color filter on the Moon?

Ron B[ee]

Well, one last look at Saturn last weekend through my 4" TV-102 Light Cup confirms that the season is over :-(, boiling away into the western horizon. I owe a debt of eternal gratitude to Saturn (and Eric J.) this year for helping me get started in sketching and thereby helping me to see more than the previous year!

One question remains. I can tell when Jupiter and Mars planetary disc is rotating. But Saturn seems, well so static. No movement in the belts, no movement in the ring that I could see. (Now I realize that ring change angle every year.) Has anyone been able to detect motion in this beautiful and unique planet? If so, how did you do it? How
long do you have to watch to detect motion?

Thanks,
Ron B[ee]