Observing Saturn's almost edge on rings

Canopus Lim · Post by **Canopus Lim** » Mon Mar 09, 2009 12:44 am

Tonight the weather had very good seeing conditions (quite high humidity, small wind). I did observation of Saturn and this is what I observed with my 12.5" Newt. While observing the moon earlier, I could see >21 craterlets in Plato in a quick count...would have more actually. This means that the seeing is very good.

Saturn at 300x to 450x magnification
(400 to 450x for detailed observation of the almost edge on rings)

1. Saturn's Globe
- 2 prominent banding. The north bending was larger and less contrast. Easily observable shadings starting from browner at the north side. The southern band was more prominent than the northern band and was thinner. Shading was also obvious
- Southern polar cap of the globe had nice shadings and was visible.
- Northern polar cap has shadings and ends at north side being darker

2. Saturn's rings...
Now this is very interesting. The rings are almost edge on and are very thin. My scope and eye was able to discern easily the gap between the rings and the globe.

Because of very good seeing, the C-ring/ Crepe ring was easily visible at 400x. It was greyish translucent. The B-ring was quite easily seen being brighter than the C-ring and not translucent. The Cassini Division was also resolvable, and looked very thin and light grey in colour (due to its small angular size at that angle, the contrast of it will become light grey). The A-ring was visible and was surprisingly quite bright but very tiny in thickness.

All in all, I found it rather interesting and a very nice test of my telescope, eye and seeing condition.

Probably you guys can try observing the rings too. Do note to have better seeing conditions, observe Saturn when it is > 70 degrees in angle. The nearer the zenith, the better the seeing.

Zephyrus · Post by **Zephyrus** » Mon Mar 09, 2009 1:27 am

Aww man, you just made me catch the aperture fever. In my case, actually the aperture cold, because I have no money to buy. xD

You must let me take a look at your scope someday, because I can only go as high as 250x on my mak. Saturn looks like a yellow dot with a line cutting in the middle on my scope. ):

Canopus Lim · Post by **Canopus Lim** » Mon Mar 09, 2009 12:11 pm

Zephyrus wrote:Aww man, you just made me catch the aperture fever. In my case, actually the aperture cold, because I have no money to buy. xD

You must let me take a look at your scope someday, because I can only go as high as 250x on my mak. Saturn looks like a yellow dot with a line cutting in the middle on my scope. ):

Yes a 5" will just show a horizontal line and will have difficulty resolving the 'black gap' between the rings and the globe. I am not sure what aperture onwards is able to resolve the 'black gap'. I would think a 8" high quality scope will be able to do that.

I am afraid if you look through my scope you get 'aperture fever'... ha.

Anyway with my 88mm refractor I am able to observe the 2 North and South bands on Saturn at about 125x and 160x magnification. The rings are unresolvable and looks like a thin line. Therefore with your 5", assuming it has good optics, and with experience, probably you can also see the 2 bands on Saturn instead of a 'yellow dot'.

Zephyrus · Post by **Zephyrus** » Wed Mar 11, 2009 1:40 am

I've already been diagnosed with the aperture fever, hahaha! I'm using the TMB/Burgess 6mm on my scope, and it give me a 250x magnification. Without motorized tracking, the object moves too fast for me to observe anything at all. I'll try using my Meade 32mm with a 2x barlow soon (if the skies cooperate) to see if I can observe the bands. Still, find a day, I'm going to look through your scope! Hahaha.

I'm also thinking of doing critical collimation on my 5" mak, but I don't have the equipment nor the experience to do so. I need an EQ mount (preferably with motorized tracking) for the 3rd stage collimation, and that is something I definitely can't afford for quite a long while. I'm hoping to find someone who has the knowledge, equipment, experience and time as well, to help me do the critical collimation on my mak.

Anyone?

Canopus Lim · Post by **Canopus Lim** » Wed Mar 11, 2009 12:36 pm

Haa..my scope is not the largest..there are people in the forum with 15 and 18inch..

Also, I am rather busy, so 90% of the time I will be observing from my apartment's ground floor. I do not have a 'fixed' day to observe. I observe whenever I am free and when the sky is clear, therefore it is very impromptu.

I would suggest that you observe Saturn's bands at about 120 to 150x so that it will be easier for hand tracking of the planet. For my 88mm refractor, it is mounted on a alt-az mount and I just do hand tracking.

Yes, it is also necessary to accurately collimate your Mak. The bands on Saturn are low contrast by nature and hard to see, more so for a small telescope.

Zephyrus · Post by **Zephyrus** » Wed Mar 11, 2009 3:18 pm

Hmm, that means I'll have to use my 2x barlow with my Skywatcher 25mm M.A. eyepiece. The quality of the eyepiece itself isn't that good already, with the barlow, I wonder how will the viewing quality be like. I'm using the Manfrotto 410 head, so it should be easy to hand track, but tedious and probably produce vibrations. Hmm, critical collimation will have to wait until I find someone who can do it for me, haha.

I think the easiest way for me is probably to get a cheap Meade LightBridge Truss Dobsonian to start with. Although the performance is of course 10x lesser than that of an Obsession, but it's a lot cheaper and more affordable for me at this point of time, haha. So yeah, either I buy a dob, or I camp at your house. xD

Canopus Lim · Post by **Canopus Lim** » Fri Mar 20, 2009 12:17 am

Just now I looked at Saturn with my William Optics 88mm refractor. The rings are slightly more open now (the last observation on 8th of March with my Newtonian was 2.3 degrees, so I guess now maybe it is 2.7 or 2.8 degrees).

I can see the north and south banding, Cassini division (looks like a dot) and the gap (looks like a thin black horizontal line) between the rings with my small scope. I counted about 4 moons. It was pretty cool, considering I could only use 123x as more than that the scope will oscillate too much due to the wind.

Post by **Airconvent** » Sat Mar 21, 2009 12:07 am

If I recall correctly, the rings will virtually disappear for 2 weeks in Sep as we cross the edge on view...

Canopus Lim · Post by **Canopus Lim** » Sat Mar 21, 2009 6:24 pm

Yes that is what is said. Apparently it became very small..then becoming larger again (now)..then disappearing in Sept. In Sept it is also not possible to see it since it will have set.