Saturn attempts

[harryb]

Hi all

I am new. I have a newtonian telescope.

I followed the manual and collimated the telescope. I pointed the telescope at the moon and got some great pictures. I then point it at what I believe is Saturn (april 9th and 10th 2011). Looked below Leo.

I focused it and see what i believe to be Saturn but now i am not sure. It was a round white ball, but plastered above it was what looked like the secondary mirror and it's three supports at 120 degrees. I moved it away and looked at the moon again and i could no longer see the secondary mirror.

I pointed it at some stars and did not see the black outline of the mirror. Point it back at where I expect Saturn to be and it is there again.

What am i doing wrong?

[JamesC]

Got me baffled. Have you got stray light entering your tube somehow, maybe a street light or something? Try doing a quick star test. Point your telescope at a bright non-double star, e.g. Arcturus. Go back and forth around the focus point. It should be a nice even circle either side of focus with a dark bit in the middle from your secondary. When it is in focus there should be 6 faint lines heading out from the star like an asterisk - these should be faint and only visible on bright stars.

If you are pointing at Saturn it should be obvious even with a poorly collimated scope. Follow the curve of the plough handle down to Arcturus, then keep on the same arc and go a similar distance to the blue star Spica. Go up and right a bit and there will be a bright orange star which is Saturn. It is similar in brightness to Arcturus and Spica.

[harryb]

Yeah I have done a star test and that comes out fine. I am going to wait for the 16th of april to try again as it will be easy to find near the moon, I am just worried that my secondary mirror will get in the way again:(

[harryb]

Hi, sorry

The thing I can see is the circular thing with the four spokes holding it in place (but on mine it is three).

from

Harry

Google Image Result for http://www.vixenoptics.com/reflectors/r130.jpg&

[briandh]

Hi Harry it sounds like your not fully focused on saturn if you turn the focus knobs it will get smaller and smaller till you can see that its saturn

attached is a pic i took on the 8th from SE london

[JamesC]

How do you know it won't be cloudy on the 16th? You don't need the moon to guide you to Saturn, just identify the brightest stars and you'll have one spare. Binoculars will show it up as not being a star, although it will be really titchy.

Going back to your scope. Were you observing visually? If you're scope is like the one in the picture you linked to then it looks like you've got some sort of extension tube for visual observation. You were using it right? Sorry if I'm wide of the mark here, but I really am baffled about what could be going wrong.

[harryb]

hi guys thanks for replying.

I found it just this hour. I was not focusing it corrently, I have 1000mm focal length with a 10mm lens so I was twiddling it to much and go the secondary mirror. (the image LOOKS about 5mm across.

The image is very small and I can see the rings. Will I need another telescope with a longer focal length to get better images or could i buy a 5mm lens for similair effect?

[harryb]

I should also add that the image is not big enough to percieve colour like in the one above.

[JamesC]

Well done. A shorter focal length eyepiece, a barlow lens or a longer focal length telescope will all give you more magnification. The only thing about short focal length eyepieces is that the eye relief can be tight so find out what the eye relief is before you buy. If you are on an undriven mount then spending $$ on a wide field eyepiece will give you more observing time before you need to shift. If you have a driven mount then maybe you can go with an orthoscopic or something. Look around for advice about what magnification to go for. I think it's worth spending on a planetary eyepiece if you can.

[JamesC]

Oh yeah and if you wait up for Saturn to gain a bit more altitude the seeing generally improves a bit, but you probably need a bit more magnification to appreciate it.

[briandh]

the picture i posted was taken with a 3x barlow then webcam (SPC-900)

20frame video which i stacked the frames using Registax 6

good luck tonights probly a good night to try again