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Deep Sky Viewing


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Hello Everyone,

I have a question....

Wife and received our Dobsonian 8" Skyliner 200P yesterday, set it up last night and started viewing tonight and had some amazing views of Saturn and Jupiter (my mind was blown) and that was with the 10mm eyepiece that came with the scope. 

My question is...how do you view beyond planets and view deep sky objects? Is that possible with the standard 25mm and 10mm, and pieces that came with the telescope?

I'm practically new to the telescope scene (last time I looked through a telescope was over 15 years ago) so I don't have much knowledge on the matter. 

A little overwhelmed so any information would be appreciated. 

 

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Hi Auxilium,

Good choice of scope, it will serve you well for a long time.

Absolutely you can see deep sky objects (DSOs) with the standard eyepieces.

The main problem currently is that the skies do not get fully dark, and won't until the nights start drawing in. This makes it a little more challenging to find things, and they do not look as good as under full darkness.

You will need to stay up until 11 ish probably to get the best possible views at the moment, and I would suggest going for some of the brighter, better placed objects.

M13 and M92 are lovely globular clusters in Hercules

M3 and M5 are also well placed currently, globular clusters again

M57 in Lyra is quite bright, though small and can take lots of magnification once you have found it

Make sure your finder is well aligned as this will help a lot.

In terms of finding your way around, Stellarium is a very good and free PC application

Turn left at Orion is an excellent beginners book to finding you way around

You can also find numerous star charts on the web to print off.

I find this a useful resource to know what is around

http://www.skymaps.com/skymaps/tesmn1505.pdf

http://www.skymaps.com/downloads.html

Good luck

Stu

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The different eyepieces will change the magnification (i.e. apparent size of the viewed object) and the field of view, not what kind of things you can see, which is mostly determined by your telescope aperture. Given their size and relative faintness you'll likely have more success using the 25mm eyepiece to find DSOs and then switching to the 10mm if you feel you'd benefit from the greater magnification. Familiarising yourself with the concept of averted vision will also aid you greatly in spotting fainter objects.

For this time of year the Great Cluster in Hercules is a fairly simple target as it's so bright. You'll immediately know you've found it when you see a large diffuse object which is very much unlike nearby point stars.

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Another suggestion is the sky and telescope pocket star atlas. Great little book. Buy a small cheap torch and ask your wife to buy a cheap red colour for nails. Then use it to paint the glass on the torch. It works perfectly for maintaining your eyes adapted to dark when looking at the star atlas in the dark.

In the future you may want to upgrade your eyepieces, particularly the 10mm. You could consider a 12mm and a 6mm. Many options out there.

You got a very nice telescope, which will give you a lot of fun on many targets!

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Thanks guys!
Extremely happy with the telescope, it's amazing and can't wait to go out there again tonight. 

So it's as easy as finding and pointing the telescope at a DSO and voila (of course, adjust focus etc..) I can see it through the eye piece given the right conditions?

The eye pieces seem to fit into other tubes that I can fit into place in the actual optical tube and it seems to make the viewing tube longer? Sorry if this doesn't make sense, I'm not familiar with the acronyms or technical parts of the actual optics. 

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Viewing Deep space objects DSO's have two necessities over planetary observing and that is a large aperture telescope 8" + (you've got that covered) secondly is a dark sky, I'm not talking about "middle of the night " dark but in the context of light pollution.

Even a seemingly dark countryside sky can still suffer from the light domes of nearby towns or cities.

Take a look at this,

http://www.lightpollutionmap.info/#zoom=10&lat=6991895.50378&lon=-334586.32737&layers=0BTFFFTT

Even if you don't live in the UK it gives you an idea as to how far the light pollution from towns and cities spread in areas

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Viewing Deep space objects DSO's have two necessities over planetary observing and that is a large aperture telescope 8" + (you've got that covered) secondly is a dark sky, I'm not talking about "middle of the night " dark but in the context of light pollution.

Even a seemingly dark countryside sky can still suffer from the light domes of nearby towns or cities.

Take a look at this,

http://www.lightpollutionmap.info/#zoom=10&lat=6991895.50378&lon=-334586.32737&layers=0BTFFFTT

Even if you don't live in the UK it gives you an idea as to how far the light pollution from towns and cities spread in areas

I live in New Brunswick and just looked for some Dark Sky Preserves in our province and there's actually 3 of them! So this is definitely good news. 

We're about 23km out of Fredericton, which is a pretty small city to begin with and there's not many lights out here but there is a street light right across the street from us which ruins it a little...

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I to have a street light in close proximity and it really has a detrimental effect on my viewing at home.

I've taken a look at your area and it seems that between Great falls and miramichi looks to be an excellent area of dark sky's, possibly north at Mt Carleton provincial park?

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I to have a street light in close proximity and it really has a detrimental effect on my viewing at home.

I've taken a look at your area and it seems that between Great falls and miramichi looks to be an excellent area of dark sky's, possibly north at Mt Carleton provincial park?

Yeah, I'll have to let my wife know since she's the Canadian and familiar with the province, haha. One of the Dark Sky Preserves is only 2 hours away from us. 

Hopefully, tonight we can try to view some dso's, which I read from an earlier post would be better viewed with the 25mm? I'm a little confused as to how the eyepiece "area" works, there's some tubes that the eyepiece fits into that then fits into the actual telescope and makes the optical tube (not familiar with the term) longer it seems like? 

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The eye pieces seem to fit into other tubes that I can fit into place in the actual optical tube and it seems to make the viewing tube longer?

I'm wondering if you had a barlow lens supplied with your telescope? I had no other "tubes" with my scope, just the supplied eyepieces and a 2" adapter. You have the focuser and should have 2 eyepiece adapters, a 1.25" and 2" that fit into it, then the eyepiece to fit into the adapter , any other tube must surely be a barlow? Does the "tube" have a lens element?
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I'm wondering if you had a barlow lens supplied with your telescope? I had no other "tubes" with my scope, just the supplied eyepieces and a 2" adapter. You have the focuser and should have 2 eyepiece adapters, a 1.25" and 2" that fit into it, then the eyepiece to fit into the adapter , any other tube must surely be a barlow? Does the "tube" have a lens element?

I feel silly not knowing if these are adapters or not  :huh: 

There's two of them, they attach to each other (screw into place) the smaller one has two thumbscrews and screws into the larger piece that also has two thumb screws...

Together

IMG_20150521_121045_zpsyejnfmjz.jpg

Apart:

IMG_20150521_121107_zpskeotjjr4.jpg

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They're you eyepieces adapter adapters, but it looks as if the bottom section of your 1.25" has unscrewed and is now fitted into your 2" adapter, undo the 2 thumb screws of the 2" to remove the bottom section of the 1.25" adapter and screw it back into place. These adapters are separate attachments and are not meant to go together. You fit the 1.25" adapter into the focuser for your 1.25" eyepieces, then remove this to fit the 2" adapter for any 2" eyepieces you buy.

Hope this makes sense for you.

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They're you eyepieces adapter adapters, but it looks as if the bottom section of your 1.25" has unscrewed and is now fitted into your 2" adapter, undo the 2 thumb screws of the 2" to remove the bottom section of the 1.25" adapter and screw it back into place. These adapters are separate attachments and are not meant to go together. You fit the 1.25" adapter into the focuser for your 1.25" eyepieces, then remove this to fit the 2" adapter for any 2" eyepieces you buy.

Hope this makes sense for you.

That makes sense to me, I reattached the 1.25" eyepiece to it's correct place. 

So these eye pieces don't have anything to do with the 25mm and 10mm?

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That makes sense to me, I reattached the 1.25" eyepiece to it's correct place. 

So these eye pieces don't have anything to do with the 25mm and 10mm?

Can't edit my posts yet so disregard my above post. 

If I am understanding this correctly, the 25mm and 10mm are both for the 1.25" eyepiece adapter? What eyepieces are used for the 2" eyepiece adapter?

Is this a correct assumption?

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Yes that's correct, the supplied eyepieces 10mm/25mm are 1.25" format for your 1.25" adapter.

Here is a pic to show the difference of a rather larger 2" eyepiece, the Explore Scientific 82° 24mm next to the 2" adapter.

post-36849-0-51359200-1432241106_thumb.j

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Hi and welcome to SGL! The Dob is a great value scope.

The 10mm and 25mm of your eyepieces refers for the focal length of the eyepiece. The shorter the focal length of the eyepiece, the more magnifiaction you'll get but the narrower your field of view will be. In simple terms, if you divide the focal length of your Dob by the f/l of the eyepiece , you get the magnification you'll see. Eg in my 200PDS the focal length is 1000mm so a 10mm eyepiece will give 100x magnification (1000/10). I hope that helps.

The eyepieces supplied with your scope are fairly basic ones. I'd strongly recommend spending a bit of money on some better ones. The Celestron X-Cel LX and Baader Hyperion ranges are pretty good value for money and you'll be surprised at just how much they improve your viewing experience. The same goes for the supplied barlow lens. It's worth investing in a better one.

Whatever you choose to do, tho, your scope will bring you many nights of view pleasure and lots of WOW moments.

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Yes that's correct, the supplied eyepieces 10mm/25mm are 1.25" format for your 1.25" adapter.

Here is a pic to show the difference of a rather larger 2" eyepiece, the Explore Scientific 82° 24mm next to the 2" adapter.

Awesome! Thanks for all the help you've given me, it's helped me understand my telescope/eyepieces much more!

Hi and welcome to SGL! The Dob is a great value scope.

The 10mm and 25mm of your eyepieces refers for the focal length of the eyepiece. The shorter the focal length of the eyepiece, the more magnifiaction you'll get but the narrower your field of view will be. In simple terms, if you divide the focal length of your Dob by the f/l of the eyepiece , you get the magnification you'll see. Eg in my 200PDS the focal length is 1000mm so a 10mm eyepiece will give 100x magnification (1000/10). I hope that helps.

The eyepieces supplied with your scope are fairly basic ones. I'd strongly recommend spending a bit of money on some better ones. The Celestron X-Cel LX and Baader Hyperion ranges are pretty good value for money and you'll be surprised at just how much they improve your viewing experience. The same goes for the supplied barlow lens. It's worth investing in a better one.

Whatever you choose to do, tho, your scope will bring you many nights of view pleasure and lots of WOW moments.

Ahhh! Ok, that makes a lot of sense, I knew some of the information but now how it came about. 

So, the 10mm with have 120x magnification and the 25mm with have 48x magnification, this is very easy to work out (which is good, I'm not very fond of #'s)...

Thanks a lot! The dobsonian didn't come with a barlow lens so that's something we will be buying soon along with another eyepiece. 

Is it good to start off with a 2x barlow or better to jump up to something stronger? What eyepiece should I be looking to buy for some deep sky viewing as well?

Thanks for all the help everyone. 

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I'd stick with a 2x barlow - with the 10mm eyepiece it will give you 240x (a virtual 5mm eyepiece) which is about the maximum that is useable much of the time. So a 3x / 4x or more barlow is not going to see much use.

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A good X2 barlow is a good addition for your scope, and as john said any more than that on your 10mm would get you poor results, leave the X3 and X5's for the imaging guys!.

I would second the suggestion by The BFJ of upgrading to better quality eyepieces, but there's certainly no rush to do so, I would advise to take your time in choosing, as there are so many factors involved when purchasing a new eyepiece:-

Eye relief - predominantly important for spectacle wearers

Field Of View - Area of sky you see in the eyepiece, (50°/68°/70°/82° and so on)

Edge of field correction (more so for the wider FOV eyepieces).

Filter use- Deep sky (nebula) filters are not cheap if you want quality, do you want one in 1.25" format or 2"? Pricey for both.

It's better to buy just 1 very good eyepiece in a year than to buy several lesser ones, it also saves you money in the long run if you didn't need to upgrade your upgrades.

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Went out last night and viewed Saturn/Jupiter again and also came across two objects that I couldn't make our 100% because they were faint/hazy, the street light that is directly across from us really messes up our viewing since it's never completely dark around our home and our eyes can never adjust to full darkness...

I couldn't tell if they were Star Clusters or a Galaxy, the 2nd object was pretty large in the eyepiece and seemed to have bands of stars going outwards (spiral like), which made me think it was a galaxy. 

Amazing nonetheless!

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I'm guessing you saw a globular cluster based on the size. There's a few of them around Scorpio which is roughly where Saturn is right now. If it was a galaxy then you have done very well indeed!

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I doubt very much it was a galaxy as they are generally very faint and need good conditions to see any detail at all.

Whereabouts in the sky were you looking at the time? M67 and M44 are two open clusters near Jupiter currently.

There are plenty of globs out there too, in the larger ones like M13 the Stars do resolve, particularly with averted vision.

Cheers,

Stu

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Was it anything like this (which sounds a bit like your description)?

http://en.wikipedia.org/wiki/Whirlpool_Galaxy

Its usually very faint unless you're at a perfectly dark site with full dark eye adaption. :)

No, it wasn't the Whirlpool Galaxy, I've been trying to locate the Whirlpool Galaxy specifically but I haven't had much luck lol

I'm guessing you saw a globular cluster based on the size. There's a few of them around Scorpio which is roughly where Saturn is right now. If it was a galaxy then you have done very well indeed!

It's in Saturns general direction but higher in the sky, I found it first in the finder scope, I looked through the 25mm afterwards and noticed that I found something and even more so when I switched to the 10mm, it's very faint but large. 

I doubt very much it was a galaxy as they are generally very faint and need good conditions to see any detail at all.

Whereabouts in the sky were you looking at the time? M67 and M44 are two open clusters near Jupiter currently.

There are plenty of globs out there too, in the larger ones like M13 the Stars do resolve, particularly with averted vision.

Cheers,

Stu

In the direction of Saturn, but higher in the sky. I found it again last night scanning the sky with the finderscope. I'll have to pay attention to the exact position I'm looking in when I find it tonight. 

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