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Daltoner

First scope help

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Hi guys,

Great help and advice on this site so far all i can say is thankyou. If it wasn't for this site maybe i would have given up on the whole astronomy thing due to lack of knowledge!

Recently purchased an 8" celestron starhopper dobsonian. 1.25 plossl eyepiece (i think ;)).

I live in yorkshire not sure my exact longtitude/lattitude. But i saw a large shiny object in the skies to my south/south east.

Charge outside with my new telescope in order to see what it was.

Thats where my problem is, through the 2" viewfinder i could see a large object hovering lowish in the sky. Through the Dob though all i could see eventually was a yellowish ball with a black dot in the middle and black lines through it (think they are the diffraction spikes??)

Tried focusing but no joy they just wouldnt go. Also i didnt get a massive amount of detail form the object in fact less than the finderscope. Where am i going wrong? I have clear sies again tonight and am determined to see what it is! lol thanks

Anthony.

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Hi Anthony

Sounds like Jupiter - looked at stellarium at aound that time in SW and Jupiter was setting very low down - try www.stellarium.org and download stellarium planitarium program and you'll see what i mean it's a great help for identifying what is out there

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Currently at work so not sure they would like me very much idf i dowloaded it at the moment ;)

Definately will when i get home though. had a look on Heavens-above (no idea how to make link) and confirmed it is more than likeyl Jupiter.

Im not sure how i didnt manage to see anything. It must be something im doing wrong. It was just a ball of light not particularly bright through my dob. (far brighter through my 2" finderscope!!)

No moons no colour nothing. Maybe it was the wrong time of night to try.

I realyl want to try and nail Jupiter tongiht if possible before it shrinks out of view and that is probably 9.30 from where i set up. Sorry for te long post but it's something I really would like to see as iv'e yet to see

anything ever through a telescope!

Thanks in advance

Ant

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Anthony..

Welcome to the forum.

You were looking at Jupiter ;)

The planet is very low at the moment which means you are looking through a lot of atmosphere which causes "Poor" Seeing, also it was warm yesterday which would cause a lot of warm air turbulence in the evenings. (Boiling)

In an ideal world the best view would be when the planets are high in the sky and it's really cold! and just after a rain storm (Cleans the air!)

The odds are stacked against us for a really good view of Jupiter at the moment.. :wink:

Also you need to give that scope some cool down time to allow it to stabilise with the surrounding temperature. Leave it for at least an hour outside and check the collimation...

HTH

Any questions, please ask..

Greg

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Thanks Gregg

Really desperate to see my first planet though hehe.

With regard to the Diffraction spikes? how do i get rid of those or are those permanent? (its a big black dot in the middle of well Jupiter and then the four lines coming outwards from it.) I just cant understand why it looked so much better from my 2" than it did from my main telescope i really am a noob lol.

I know those are a common ocurence in newtonians. But it literally split the ball of light into 4 segment. With a hole in the middle. Should i let it cooldown longer? Is it collimation? (looks fine when i do the eye test)

Really confused

Thanks for the help guys really appreciate it.

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If you're getting a bright blob with a hole in it, you haven't reached focus. Find out which end it is at then we can work out how to fix it. If you wound the focuser all the way out, you can try not putting the eyepiece quite all the way in, or you'll need an extension piece. If its all the way in and not there yet, you have more to do but that shouldn't be the case.

If you have a Barlow lens, you can take the end lens off and use it as an extension tube to get further out, or use it as is if you can't go in enough because the Barlow needs less in travel with any eyepiece.

Kaptain Klevtsov

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What sort of extension piece would i need?

I dont have a barlow no, can you recommend a good one from FLO?

i dont want to get the revelation kit until i crack this.

Yea thats kind of exactly what im getting. And its too cloudy now to try again.

Yea i had the focuser all the way in and all the way out and no joy, the blob stayed.

I will try not putting the Ep all the wy in i didn't try that earlier. Akyra who owned the telescope before me didnt have any problems with the focus but he did have a barlow.

Any other bits of advice? anything no matter how small is greatly appreciated

Thanks

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I think you will find as KK (I think) said, that you dont have enough outwards focus. I have the exact same problem with my newtonian. You can either get an extension tube (Between 10-15quid) a cheap barlow (20quid upwards). The Barlow should allow you to remove the lens and use it as a straight extension tube OR leave the lense in place and have double the magnification from your Eyepiece.

Dont worry 'bout this as I say I have exactly the same problem, 'tis easily sorted ;)

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I just sold my Celestron 8" Newt but as i replaced the focuser on mine I still have the original focuser plus all the extension adapters (1.25" & 2"). PM me if you are interested in a spare Celestron focuser plus all the adapters for a lowly sum (the focuser plus 3 adapters for £15 delivered) ;)

Regards

Russ

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Hello,

I live in North Yorkshire and I also have an 8" Starhopper :wink: As the others say, it was jupiter, I must say that the 8" StarHopper is a good scope for looking at the planets, last summer I managed to see atleast 5 moons around Jupiter with the cloud belts easily seen. Although last year Jupiter was higher in the sky, this year though it is lower in the sky and I can't view it as easily due to thermal currents from the surrounding landscape and it is only vsible for a few hours around sunset ;).

Below is a few things which may help you with your scope from now on.....

Firstly I agree with the fact that your eyepiece was out of focus, you were seeing a big yellowish circle with a black hole in it, yeh? The only thing I can suggest is that on the underside of the eyepiece holder there are two turning knobs (not the big silver ones to focus on the sides) which tighten/loosen both the 2inch and 1.25 inch eyepiece holders, I suggest that you make sure that the one nearest the telescope tube (lower one) is loosened slightly and that the higher one (nearer the eyepiece) is tight but not too tight, if both are tight then the eyepiece will not focus so make sure they can move. However if you have both of them too loose then the eyepiece will just fall into the hole.

Secondly, do not try prime focus astrophotography with this scope as it does not provide enough of a range for focusing so you will just be left with the above (circle with a hole in it). Also the dobsonian is an alt/azimuth mount so tracking is out of the question, short exposure prime focus photography with a camera will add weight to the scope and you will find it near impossible to balance the starhopper. I have been able to take some good images of the moon though with just a camera phone (2 MegaPixel) afocally, give it a go.

Thirdly, I have had the scope for just over a year now and found that the tension handles have loosened, now I know that they do loosen (obviously) so you can move the scope around, but mine could not tighten at all, upon inspection I found that the brass / gold coloured sockets which are built into the black plastic circular tube holders have come out, they appear to have been heated up and sunk into the plastic when built but over the past year of tightening and re-tightening by myself they have popped out. My father and I found that by heating them up again and re-sinking them then it sorts the problem out, this is maybe somehing which Celestron should modify as common sense usually shows that plastic does not easily support metal!

But be aware because you may find that within a year you come across the same thing.

Fourthly, as you may know, rotate the turntable clockwise when observing (or moving) as to not loosen the screw at the base of the mount.

Hope this helps

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Thanks mate

You know youve said a couple of things there that i prob did wrong. the first time i tried everything was tight and when i moved the focuser nothing happened, then i loosened both fully, and it did just as you said fall into the hole.

No i have to wait until another clear night.......

I will definately try that, Is there anything fairly easy i can start looking for up in our general direction? south/south east is prob my best bet, or ;) around polaris.

love to get jupiter nailed just no sure its possible although i did have a good chance for around an hour just didnt know waht i was doing and then it went lol

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No problem ;)

Sounds like you have just the same viewing parameters as me, I can view the southern, eastern and western horizon from my back yard. There is a whole host of things for you to look at at this time of year in this region of the sky. I could go on for ages but I will narrow it down to a few for you...

NOTE: It will greatly help if you download a star chart, I use TheSkySix but I got it with my NexStar, a good free program is Voyager 3 from Carina software. It's only a demo but its as good as, you can pinpoint your position on a global map in the settings tab once loaded, enter your date and time and it will show you a clear image of the constellations etc along with planetary orbits.

As you know Jupiter is quite low in the sky in the South / South-West direction, give it another shot with your starhopper, once you get it focused you will be amazed at what you can see, although thermal currents from surrounding terrain may interfere with your vision of cloud belts but you will most likely be able to see the Galilean Moons (Medici's) of Io, Europa, Ganymede and Callisto and maybe a few others. Although not really feasable at this time of year due to its short time above the horizon try to watch the moons over a period of time and you will see them change position as they orbit Jupiter.

So you have jupiter towards the south-don't worry about your telescope for the moment, I assume that your new to astronomy and perhaps need to learn your way around the night sky (no offence here if you already capable with ths part)? If you turn to the west, slightly higher up you will see a bright orange star - this is Arcturus in the constellation Bootes, not far from this further to the north and a slight higher is Ursa Major (the stars of the plough are clearly visible, even just an hour after sunset).

If you want to look at some objects in this region of the sky, there is Bode's galaxy (M81) and the Cigar galaxy (M82) which lie just above the right end of the plough. I have viewed both galaxies with the starthopper and they are a joy to look at as they both resolve well in the same field of view. However it takes a bit of luck to find these two galaxies and at this time of year you are better leaving until well after sunset as the sky is not dark enough in the west. A good thing about the dobsonian is its easy manouverability. If you can't find them don't worry.

If you turn back to the south, look directly up, you should see a bright white-ish star, this is Vega in the constellation Lyra. I used this star, Arcturus and Deneb in Cygnus to form a triangle to help me when I started out in astronomy. Cygnus is right next to Lyra towards the NorthEast and is clealy seen as a cross going NNE to SSW. There is a whole heap of objects to view in this region of the sky especially with the 8" starhopper, primarily M57 the Ring Nebula, M27 the Dumbell nebula, M13 the Hercules cluster and M92.

M57: Start with Vega you should notice a diamond shape of stars pointing south from it, M57 is positioned between the bottom two stars of this selection and will appear as 'a blurred ring around a black core'. Use Voyager to help you with your search.

M27: Again start with Vega but take the bottom star in the cross of Cygnus and move your telescope that distance and then half again, you should find M27 quite easily.

M13: This and M92 lie in the constellation of Hercules. Its positioned between Lyra and Bootes but closer to Lyra, find a square of stars tilted north and use this as a base for M13 and M92. M13 is situated between the two western stars of this square whereas M92 is above the top of the square towards the eastern side.

I hope that this helps, it's only a rough guide and you will probably find that you need a good few nights viewing to find everything, there are loads more out there but these things are the easiest. Learn to star-hop and learn simple ways to find those 'interesting' objects so you don't need star charts, if you need to use a star chart (from a book) use a red filter on a torch to help preserve your eyesight, I use a simple rear bike light lol.

If you want any more info about finding basic DSO's such as M31, M29, M71, M11, NGC 869 etc just ask.

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Did you follow the advice I sent you in a PM about the focuser? EA2007 pretty much covered it in an above post too.

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Yea slowly but surely, I can get it very close but just not close enough for some reason hehe. Havent had a decent night to test it either and theres nothing far away anough during the day that i can test it with from my house. Guess ill have to put my thinking cap on hehe. Its a great scope though akyra, had my friends just dribbling over the size of it!

Yea EA2007 did a really good job of it! Cant wait to try for some of the things hes mentioned.

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