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2nd time out... need advice!


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Where do I start... 

Well I bought an Orion Skyquest xx12g, a 12" goto truss dob, a couple months ago and finally got a chance to set it up in my back yard 10 days ago. Collimation went great, and was actually a lot easier than I thought it would be. It was a full moon and the air was hazy, but I got an ok look at Jupiter and learned alot about aligning and operating the scope.

I got to take it out again last night. Very clear sky, got some good looks at Jupiter through a 10mm Delos, and there were a lot of stars visible to the naked eye.

But here is my issue. I want to take a tour of deep space objects, Great! The problem is that I have no idea what I am suppose to be seeing. For instance, it will say beehive cluster, or double cluster and if I choose that object and the scope slews to it I really don't know what I am looking for. Part of this issue is the accuracy of the Goto function. It seems to be about 1 degree off no matter what I do. This is no problem if I am checking out Jupiter, or a double star I know like Mizar. I can just slew the scope manually, put my red dot right on the object, and it will be in my eyepiece. But if I don't no what I am looking for and the Goto function is about 1 degree off, How the hell do I know what i am looking at? I did quite a bit of looking around like this with a ES 82 30mm, and it was very cool, but the real fun of astronomy for me is the knowing what I am observing and learning about it. Another issue is what ep to use for what object. If I knew I was looking where I was supposed to be I could experiment with the 10mm Delos, ES 82 30mm, and 2x powermate I have, but not knowing if I am centered on object I don't know where to start.

So... any suggestions? I thought about looking up the clusters and other object's picures, but that won't really do me any good looking through an ep. I use the crosshair ep that came with the scope for alignment and I have tried to be as precise as possible. I tried with many 2 star combos with Polaris, Vega, Arcturus, Regalus, Procyon, and always end up with the same results. It is about 1 degree off. I went back and looked at all the info I put it in and it is all good. This has started to annoy me a bit.

One last thing, even though at times Jupiter and 3 of the moons looked great, it would seem to go in and out of focus quickly. Is this my eye? Not keeping steady with the ep? Or could it be my primary mirror cooling down? We have drastic temp swings here in North Dakota. It was 60 when the sun went down and I had some frost on my ep case by midnight. What does it look like when the mirror is changing temps?

All in all I am enjoying it. I think I will stay up late enough tonight to get a look at Saturn. I look forward to getting it out to some truly dark skies in the future.

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Clusters are simply a bunch of stars, Open Clusters are generally fairly widely spaced so they can be nice but I suspect they do not have the impact that many wouild expect or want. The Pleiades are good but they are close, bright and still have wisps of nebulous gas. They are also disappearing from sightr early on.

Globular clusters are likely better, they are huge collections of stars that have drawn themselves into sphericalish group. M13, M3 (I think) are good.

The get a "list" you can try:

Enter "list of Messier Objects" into google, then go to the Wikipedia entry, you can reorder the table by type, that puts all Open Cluster and Globular clusters into individual groups.

Download Stellarium, set your location and then press f4 and set the DSO dispaly option to mag 6 or mag7. That removes lots of dim objects, then starting from say the East scroll round and write down the Globular Clusters and where they are. Open clusters are a "*" and globular are a "heavier" circle with a cross in it. Apologies that is about the best I can describe it. Also maybe start in the West as they are disappearing below the horizon as the night progresses.

If I recall M3 is sort of vertically above Arcturus (red star) in the Eastern sky. M13 is still fairly low but should be an option - you can see it just in binoculars to help locate it. With that scope try the Leo Triplet of galaxies also.

Concerning the Jupiter focus it is very likely the atmosphere, if you can look up the Jetstream and see if it is above you, if so the that is likely the problem. Actually if I recall the US weather mentions the Jetstream a fair bit. Don't go too mad on magnification.

Also be a little wary of using Polaris as an alignment star, Polaris is sort of due North and that often means a value close to zero in the computations, computers do not like zero. We humans like Polaris but goto's are not so keen on it.

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Do you have a dew heater/shield? If you get frost on your mirrors, they would make it very hard to get it off or see anything, or even do some damage.

Going out and in focus.....this would have been bad seeing (turbulence in the atmosphere). On some nights it's really good, and some nights it's rubbish. Don't try to constantly change the focus, just wait for it to go steady.

Can I suggest not doing the tour function? Get a good book like an illustrated guide to astronomical wonders, which goes through each constellation and has a short paragraph on each of the easiest DSOs in there. It should give you an idea of what you're looking for and provide you with enough objects for at least a few years.

Also challenge yourself - try not to use the goto every now and again so you can get used to the night sky and learn your way around it. Maybe give yourself 15mins to find your target, then after that you use the goto.

 

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The post ".....What can I expect to see?" under "Getting started with observing" is very good and shows a comparison of photographs and sketches, with the sketches giving a good indication of what it looks like through the EP. 

John

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44 minutes ago, ronin said:

Clusters are simply a bunch of stars, Open Clusters are generally fairly widely spaced so they can be nice but I suspect they do not have the impact that many wouild expect or want. The Pleiades are good but they are close, bright and still have wisps of nebulous gas. They are also disappearing from sightr early on.

Globular clusters are likely better, they are huge collections of stars that have drawn themselves into sphericalish group. M13, M3 (I think) are good.

The get a "list" you can try:

Enter "list of Messier Objects" into google, then go to the Wikipedia entry, you can reorder the table by type, that puts all Open Cluster and Globular clusters into individual groups.

Download Stellarium, set your location and then press f4 and set the DSO dispaly option to mag 6 or mag7. That removes lots of dim objects, then starting from say the East scroll round and write down the Globular Clusters and where they are. Open clusters are a "*" and globular are a "heavier" circle with a cross in it. Apologies that is about the best I can describe it. Also maybe start in the West as they are disappearing below the horizon as the night progresses.

If I recall M3 is sort of vertically above Arcturus (red star) in the Eastern sky. M13 is still fairly low but should be an option - you can see it just in binoculars to help locate it. With that scope try the Leo Triplet of galaxies also.

Concerning the Jupiter focus it is very likely the atmosphere, if you can look up the Jetstream and see if it is above you, if so the that is likely the problem. Actually if I recall the US weather mentions the Jetstream a fair bit. Don't go too mad on magnification.

Also be a little wary of using Polaris as an alignment star, Polaris is sort of due North and that often means a value close to zero in the computations, computers do not like zero. We humans like Polaris but goto's are not so keen on it.

I will have to check out Stellarium. Thanks for all the object suggestions.

25 minutes ago, Joe12345 said:

Do you have a dew heater/shield? If you get frost on your mirrors, they would make it very hard to get it off or see anything, or even do some damage.

Going out and in focus.....this would have been bad seeing (turbulence in the atmosphere). On some nights it's really good, and some nights it's rubbish. Don't try to constantly change the focus, just wait for it to go steady.

Can I suggest not doing the tour function? Get a good book like an illustrated guide to astronomical wonders, which goes through each constellation and has a short paragraph on each of the easiest DSOs in there. It should give you an idea of what you're looking for and provide you with enough objects for at least a few years.

Also challenge yourself - try not to use the goto every now and again so you can get used to the night sky and learn your way around it. Maybe give yourself 15mins to find your target, then after that you use the goto.

 

No dew heater/shield. I looked at the mirror a few times to see if it was getting any dew on it. It didn't.

I was trying the tour function only because I really didn't know what to look at, or try to look at. That guide looks like the kind of thing I need.

I was using the goto hoping it would put me directly onto the objects, because I really don't know what I am looking for. So If you are looking for a DSO don't you just use the constellations as guides? I guess I feel like I would still be learning the sky if my goto worked properly as can look in my viewfinder to where my scope is pointing when viewing a DSO. I am studying the sky as I use goto, not just blindly looking into the ep.

 

Is 1 degree error normal for goto? I thought it would be much better than that.

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9 minutes ago, Starwiz said:

The post ".....What can I expect to see?" under "Getting started with observing" is very good and shows a comparison of photographs and sketches, with the sketches giving a good indication of what it looks like through the EP. 

John

Thanks, I will have to search around some more when the sun is up. I have done so much reading and research the last 6 months just to buy this stuff. Guess I am ready to get out and observe.

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Is it possible to do a 3 star alignment? That would be more accurate. It might work better if you get the base perfectly flat using a spirit level.

I've heard that goto telescopes are usually a little way off, but I don't own one so I don't know how much.

Once your scope thinks it's found its target, you could look through the finder and compare it to an atlas, which should help you make a few small adjustments. Then look in your eyepiece with the biggest fov, and it should be roughly there.

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You sound like a prime candidate for the book "Turn Left At Orion". It introduces you to a whole bunch of "first" objects with finding instructions, info and description, equipment suggestions, and a sketch showing how the objects look in a scope eyepiece. You'll also find it useful to work through the monthly "Deep Sky Objects" section of Sky at Night magazine. Both were invaluable to me when I first started and you soon build up a repertoire of objects in your head month by month. Hth :)

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I have no idea what the normal error is on a GOTO set-up but I can tell you what I get on mine.   On a bad night it is about 0.4 degrees out, on a good night about 0.2 degrees out.   Sometimes it is consistent across the sky, sometimes how accurate it is depends what part of the sky I am looking at.    I regard 0.2 degrees as very usable and 0.4 degrees just about OK as it puts objects towards the edge of the field of view with my longest focal length eyepiece.   Why does it vary from night to night?  - presumably how well I have polar aligned (you don't have to worry about that as you don't have an equatorial mount) and how well I have been through the GOTO alignment procedure.

I use 2 star align plus 3 or 4 calibration stars.   I work out which stars I am going to use on any night before I go out.   I pick one to the south and one to either the east or near the zenith for the initial align and then others scattered around NE, E and zenith for calibration (west is a wipe-out in my garden due to trees).   Important to get a good spread.   Your Skywatcher GOTO will be different from my Celestron GOTO but the idea of getting a good spread still applies and using as many stars as possible is a good idea.   I use quite a high magnification to centre the stars.    I normally do the centering at x200.

You should be able to spot planets and clusters easily.   Galaxies can be tough (M31 being the easiest) and most nebulae are tough (M42 is an exception) if you have any degree of light pollution.   But practice helps - it gets easier to make out faint objects once you have done it a few times.   M81 and M82 are good practice objects in my opinion;  I used to find these hard but now find them easy.    But some objects are just not doable in my garden and will need a trip to a dark sky to observe and you may find the same.

Someone posted this link to a set of Messier object sketches a few weeks back.    A really great set of sketches that will give you a good idea of what to look for.
   http://www.deepskywatch.com/messier-dso-sketches.html

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My base is leveled with a bubble level and very stable. I made sure the stars where dead center in my 12mm ep with cross hairs. The scope only has 2 star alignment. It would be nice if it had 3 star, seems like it would only help. Looking now I see it has pointing accuracy enhancement (PAE). I guess that you recenter a bright star after aligning and that will help with accuracy in that area of the sky. Is that what you mean by calibration, Riemann?

Thanks for all the tip advice everyone. This place is so helpful. Looks like the sky should be clear tonight. I think I will have to stay up to check out Saturn.

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Perhaps something like a 9x50 RACI finer would be useful. This has a wider field of view than the scope, but does magnify unlike the red dot, so you can often see the brighter objects in the finder. This would help you centre them in the eyepiece provided your finder is aligned accurately.

Always use the 30mm 82 when looking for objects as that will give you the widest field and best chance of the goto getting it right. Can you goto a known star near the target, realign on that then try for the target with the goto?

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3 hours ago, Stu said:

Perhaps something like a 9x50 RACI finer would be useful. This has a wider field of view than the scope, but does magnify unlike the red dot, so you can often see the brighter objects in the finder. This would help you centre them in the eyepiece provided your finder is aligned accurately.

Always use the 30mm 82 when looking for objects as that will give you the widest field and best chance of the goto getting it right. Can you goto a known star near the target, realign on that then try for the target with the goto?

You are talking brighter objects, but not bright enough to see with the naked eye I assume? 

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21 minutes ago, dreamlander said:

You are talking brighter objects, but not bright enough to see with the naked eye I assume? 

Yes, that's right. Red dot finders are great if you know where to point them, but they don't show you any more than the naked eye. A 9x50 is effectively a small telescope and will show more stars to help guide you, and the brighter DSOs like M13 or the Double Cluster for instance.

I do think you should be looking at ways to sync your goto to targets so that the accuracy is better though. I don't know your scope so can't help but perhaps someone else can

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Sound advice from everyone,just to put my oar in, is your finder scope aligned with your eyepiece....It took me ages to work this out as i was having the same problems as you,now GOTO is spot on and any objects are usually within a low power eyepiece.

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7 hours ago, des anderson said:

Sound advice from everyone,just to put my oar in, is your finder scope aligned with your eyepiece....It took me ages to work this out as i was having the same problems as you,now GOTO is spot on and any objects are usually within a low power eyepiece.

Yes. This is spot on. I can put the red dot on Jupiter, or bright star, and it is right there in the ep. Even with the 10 mm Delos.

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You have a 12" scope if you point it at a globular cluster you will see........a globular cluster. It will look exactly like a picture of one, well actually better as it is twinkling away like diamonds on velvet.  Believe me you'll know what a glob is if you get one in the eyepiece. A 12" scope will resolve the brighter globs with ease. I'd suggest that you start your deep sky venture with a few of these :) 

Open clusters also look like their images. It's only galaxies and nebulae that will look like fuzzies.

Have fun out there. 

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14 hours ago, dreamlander said:

I guess that you recenter a bright star after aligning and that will help with accuracy in that area of the sky. Is that what you mean by calibration, Riemann?

On Celestron mounts calibration is actually part of the alignment procedure (at least on the equatorial mounts).    There is a separate thing called Sync which can be done after alignment which entails re-centering on stars after GOTO and which is meant to improve accuracy in that part of the sky.   This sounds like the equivalent of what you are talking about and must be worth a try.

It is hard to know what is inside the alignment algorithms of your scope.   A 2 star align gives 4 pieces of info to the mount when 3 are needed to align the scope.   4 is actually better as there will be an error in each piece of info - hopefully the algorithm will use all 4 pieces and not throw one away.   If the algorithm is optimal then the best results will be given when your 2 alignment stars are at right angles to each other.   If your use manual does not give guidance on stars to pick then this again would be worth a try: pick two alignment stars at right angles - it shouldn't matter if the are say S and W at the same altitude or say N low to the horizon and directly over head, etc etc just so long as they are roughly at right angles from earth.

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3rd time out. I didn't get out until about 3 am so it was kind of a short session. Got a good look at Saturn, that was super cool. Could not get the goto function any more accurate. Didn't find any DSO's, but did spend a lot of time with the star charts just learning the sky.

I came to a couple conclusions though:

1. I need to get out to a dark location. The 6 or so street lights and trees in my view were really starting to annoy me.

2. I need an observing chair, and I think an eyepatch would be nice.

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An RACI 8 X 50mm or 9 X 50mm finder-scope will be a big help. As will 'training the drive' of your scope. Look up information on doing so for your particular brand of GoTo - Orion (USA). I use a Meade, so I don't know how to 'train' yours, but I imagine it is similar - and quite easy.

Good info so far in this thread. And a very good scope, too! I've read-up on these amazing behemoths. You made a good choice! Now as for observing-chairs - one can build one oneself if you're good with tools. And one's, with adjustable-height seats, are readily available. Here's an image:

stardust_chair1.jpg

Others out there have straight-down front legs. I suggest avoiding these as in soft ground, they can sink. Another possibilty are Drummer's Stools. Commercially available and pretty low-priced. Ditto for "Ironing-Chairs." If you put the word "Astro" into the name of a product, the price tends to go into orbit.

As for streetlights and their ilk, you might find some useful information from the International Dark-Sky Association:

http://darksky.org/

They can help you develop a plan to approach your town-council to tame your lighting issues.

Have fun!

Dave

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What kind of hand set do you have?

I have a Synscan v4, that is sometimes a degree or more out, simple fix is . Once aligned go back to setup,  press enter scroll through till you find sync encoder press enter. It will ask you to choose from one of your alignment stars.. choose one and press enter. The scope will slew to that star,  re centre the star press enter and that should do it.

Hopefully this will work, it does with mine every time. 

I also did a firmware update which added altitude to the setup process. 

Nige

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