Managing expectations

[dmh1]

Hi - I am new to exploring the skies and am not sure what to expect from the equipment I have so any advice would be much appreciated. I have a Celestron 130GT with 6mm, 9.7mm, 12.5mm and 20mm eyepieces. Can anyone advise me on the following please?

1) Planets - what level of detail should I be able to see on Jupiter for instance? Through any of the eyepieces I can see the disc , which is brightly lit, virtually colourless and just the very feint equatorial band - maybe a hint of the second, and of course the moons appearing as small stars. Should I expect to be able to increase the magnification to get more detail or is there a way to manage the light balance to get more contrast? The disc appears only about the size of a 5p piece at the moment.

2) M31 - I have tried to locate this - I think I have but it only appears as a grey blob - nothing like some of the images that I see and much smaller thatn I expected - only about 1.5cm across. Should I expect to see more, am I looking at the wrong thing?

3) lastly, for now at least, I havn't had much success with setting up the auto-align for the go-to function. I align with North, and then with 2 stars but when I select another object e.g. Jupiter, the slew is not that accurate - no closer on average than about 100-150 Arcoseconds. Am I expecting too much, are there some hints or tips that help improve accuracy?

Sorry to sound such a numpty - any advice appreciated.

Regards

dave

[pvaz]

1) Planet details depend on collimation, if you let the scope cool down or not and on the seeing conditions. You can control 2 of this, the seeing is all about luck, observing for long periods hoping for the odd intervals when it just gets sharper for a second and just being lucky on the weather.

2) M31. That's it. You need a much larger telescope to get some structure and even so it will be gray and hard to see. The photos are combined hours of exposure, using sensors sensitive to invisible light and combined with post processing technices.

3) Try to center the stars in the FoV when aligning to improve accuracy. If the goto gets the object on the FoV of your lowest mag EP then it's ok.

This sketches, by Talitha, are very good and will give you an idea of what to expect: http://stargazerslounge.com/members/talitha-albums-deep-sky-sketches.html

Check the scope used, the ones with spiral arms details are done with a 16" dob.

[ollypenrice]

The live view cannot begin to approach the images in some ways. Detail on planets and nebulae is a fraction of what the imagers can capture. It's a shame I know! But stars resolve into smaller points at the eyepiece and you have the thrill of 'being there' in real time. So something like the Trapezium, four stars in the heart of M42, are far easier to resolve at the EP than the camera.

The camera can accumulate light over time, the eye cannot. But your scope has plenty of lovely targets, fear not. Try the Double Cluster in Perseus. Mmmmmm, you'll love it!! Or the Pleiades. Or the colourful double star Albireo in Cygnus, the head of the Swan.

Olly

[JamesM]

Dave, you might want to read thishttp://ww.cloudynights.com/documents/nexstar130.pdf as this is a review of your scope by the owner himself. This is aimed at your GOTO difficulties and the style of writing is very friendly and helps clarify the capabilities of your scope.

James

[ronin]

If Jupiter appearsthe size you say (5p) then I suspct that is as good as you will get. Looking at it the other night and really there isn't a great deal of detail.

At the expense of causing upset I will say that through a refractor it is sharper. I think that reflectors can often produce a "softer" image but a reflector is has a bigger light collection. A 130mm refractor will be simply very expensive. Wondering if you have gone for magnification as a smaller image may well show more detail. Bigger is not better always with an image.

M31, one of the best examples of a faint fuzzy. Slight grey patch in the sky. Sorry that is it.

As to the auto-align, puzzled. You align it, it isn't auto? Usually inaccuracies are down to simple mistakes when data is entered. Unless you can literally state everything that you did enter, and miss nothing out, then it is guesswork. Will say that care taken to level the scope base is worthwhile.

When first aligned don't belt off to Jupiter. Planets are not as predictable as the stars, they move too much and don't follow the ecliptic exactly. Wondering if that is the problem for Jupitor not being accurately found. Be realistic the handset doesn't have the memory and processing of a PC so for a planet I could understand innacuracies coming in.

It may help to first go to a nice bright star, centre that then press do the PAE action.

[Ags]

When I first looked at Jupiter a few months ago I was so disappointed - it was just a tiny, glaring, white dot bisected by the harsh stripe of the NEB. Patience however reveals subtle details - bands, markings and colors. I've come to prefer Jupiter to Saturn - there is so much more happening on J (and around it).

My best view of M51 was with a pair of cheap 10x50 binoculars. I could clearly see the core and a faint ellipse of nebulosity around it, where the galaxy's disc would be. It really looked like a galaxy, but I wasn't seeing dust bands or anything intricate like that! It was a wonderful sight, but you can only see it from dark skies.

EDIT: My GOTO scope can't find planets either. But they are bright and obvious, so no problem. It's pretty accurate for faint deep sky objects.

[Ant]

The goto accuracy could be down to polar alignment.

But having a goto accuracy of 100-150 arc seconds would be more than adequate I would have thought.

Jupiter is around 40-45 arc seconds from memory - so you are only out by around 3 Jupiter discs - that's good enough to put anything in the EP FOV...

Ant

[DrNeb]

lol yay! now i'm scared about getting my new/first scope! i knew that the DSO's werent going to be very impressive without a DSLR hooked up (Which isnt going to happen because im ordering a dob)

i hope my 250px will be worth it i cannot wait to see Jupiter...

[dmh1]

Many thanks to all for the replies - all really helpful.

Having spent some more time viewing last night, when the sky became very clear after about 9pm, I would revise my estimation re size of Jupiter I was seeing - I said 5p piece, it is not that size. The best view I get is with a Meade 4000 9.7mm, with this EP it is probably still only around 1cm across. Thought tiny, I could occasionally make out a bit of detail though beyond the NEB. Do filters help and is it worth adding a Barlow or does that reduce quality to a point where it is not worthwhile?

Thanks again

Regards

dave

[Ags]

I think your scope has a focal length of around 650mm, so the 9.7mm EP is giving you around 70x magnification. You should be able to go double this at least - but I'm not sure how good your barlow is.