Jupiter turns into orange halo

[Jemmo]

Hey all last night I was trying to see Jupiter through my 3" Newtonian I now it's not a great scope to see Jupiter with but I couldnt really focus on it I kept getting and orange ring or halo. What causes this

[ralph1]

Hi Adrian. That sounds like the telescope isn't focussed properly. Turn the focus knob(one of the two knobs beneath the eyepeice) until jupiter(or any other object) appears smallest and sharpest. On jupiter you should see a small disk with up to four dots in a line beside it. Those are jupiters galilean moons. Depending on the magnification you might also see two or more stripes on jupiter itself. Those are its cloud bands.

[raymo]

I don't mean to be patronising,[not knowing your knowledge level],
but are you sure you were looking at Jupiter? It doesn't rise until
around midnight, and would not be high enough in the sky to be reasonably well viewed until around 1.30-2.00am. I've never heard of anything resembling a ring or halo around it. Maybe it could happen with a child's toy scope with a plastic lens. Even a budget level 3" Newt
should give a nice sharp image of Jupiter.
raymo

[ralph1]

I often see Halos around the moon from haze. Why couldn't a similar thing happen to jupiter? if you go outside around midnight jupiter is the brightest object in the sky, about one handwidth up from the horizon in the northeast.

[Jemmo]

Jupiter is visible at 11pm in my area and yes I'm 100% it was Jupiter. I don't mean it has a halo around it I get like a black dot in the center as if it's doing circles very fast like a donut shape. It was quite a windy night as well

[Larryp]

Sounds like you are not achieving focus.

[OzStarGazer]

I think that a doughnut shape indicates that your scope is out of focus. Is the image tiny or big? I have noticed a doughnut shape when my scope was out of focus; specifically the image was too big.

[Jemmo]

Ok thanks guys I don't think my scope will get a great shot of Jupiter think it's a bit small I got the donut to go away but I couldn't get a great shot just an orange circle couldn't make out moons or lines etc

[ralph1]

Any scope should show jupiter well - it shows a clear disk and moons in 10X50 binoculars.

[OzStarGazer]

My refractor is just a bit bigger (90mm) and I can see it very clearly, including the moons and the bands, even with my 25mm eyepiece when the weather conditions are not too bad. But yes, it is small. :(

[raymo]

The black dot you are seeing in the middle of Jupiter will almost certainly
be the scope's secondary mirror, which means that the focus is well off.
If you focus so that stars are as small as you can get them you won't be far off with Jupiter. As Ralph said, even 50mm binos will show it clearly, so either you are not focussing properly, or something is drastically
wrong with your scope.
raymo

[Jemmo]

Was clear night but very windy. I think maybe I was trying to zoom too much I had the 1.5x erecting eye peice on then worked up to 9mm lense. Maybe I should ditch the 1.5 piece and use a lower lense than the 9mm I have a 12.5 and 25mm lense too. I reckon I was pushing the scope past its limits

[barx1963]

Adrian
Always start with your lowest power and build up from there to find the best image.
Also waiting until it is reasonably high in the sky will help.

The black dot you were seeing is actually the secondary mirror image. If you find a reasonably bright star in your scope and defocus the same black spot will appear, nothing wrong with the scope, just another normal property of newtonians.
One other thing, your mentioned using a 1.5x erecting eyepiece. 2 comments on these, they tend to be very cheap accessories, the one I had was very poorly made, and are usually supplied so a scope can be used for terrestrial targets, as a result are designed to be used with low power and not necessarily focussing at infinity.


Malcolm

[barx1963]

I realise your scope is a 75/700 now, so a 9mm with a 1.5x erecting EP will give 117x, which for 3" is pushing it, not impossible but would need good seeing and for Jupiter to be highish.

[Jemmo]

I'll try again with no 1.5x piece when it's clear. I'm actually picking up a 10" dobsonian on sat. I don't get lenses I only have the ones that came with the newt. Which wasn't very expensive. What are a good set of lenses that aren't real expensive. As I'm low on cash after buying the dobsonian. The cheap lenses will do for now but need to upgrade. Also are the filters good to get. I have a moon one no colors though

[barx1963]

Adrian
Are you able to post a picture of the eyepieces ( that is the correct term, lense refers to an element within the eyepiece) that you have? Or any descriptive text that is on them. Just gives us an idea what you have so then can suggest a suitable upgrade.

Malcolm

[creeksky]

Shouldn't he see Jupiter and moons even as a large white disc?
Not questioning your expertise,but with a 20 mm refractor 40 years ago I could make it out?

[barx1963]

The question is whether the 1.5x erecting eyepiece and the 9mm EP are able to achieve focus, they may not be designed to do so. He shoudl be able to see the disc and the moons even with the 25mm EP. From experience best procedure with any object that required power is start at low power and work up from there.

Malcolm

[OzStarGazer]

I think Malcolm meant that the 117x magnification would be too much for the OP's scope. Lower magnifications would be fine to see it (even if small).

[Jemmo]

I can't get any photos of the eye peices at the moment. The best info I can give is that the telescope I got was a gift it's one of those generic brands which I tihk there may be like 5 different brand names. Mine is a national geographic 75/700 Newtonian I think it's around the $200 mark so yeah don't think the eye pieces will be much chop

[Jemmo]

These ones here look very similar to what I have except I have 3 eye pieces instead of two

[Jemmo]

Are these ones ok for a while. I'm only a younger guy so don't have a huge amount of money. But bang for buck are they good

[AstralTraveller]

Celestron eps won't be bad. However I wouldn't jump into a 6 ep set, esp if you see it as a stop-gap. I'd form a plan as to what I wanted my ep set to look like then prowl the IIS classifieds. There is, for example, a nice 9mm TMB clone going now. Second hand gear in good condition is normally 2/3 to 3/4 of the new price, so the accumulated savings can be considerable.

[Jemmo]

David I was just reading more about that set I put up and realized I dont really need that many I might just get 2 or 3 to start with and yeah great idea I got the dob off this page so I will look for some eps too. Since I'm a total noob could someone tell me good brands to look out for and just say I'm going to buy 2 or 3. What sizes should I go for

[jenchris]

My friend's 50mm guide scope with SSAG picked up jupiter (with cloud bands) and the moons the other night.
I think a 75mm Newtonian would be fine and would replicate that at least.
The focus does sound to be off - which could easily be caused by too long a light train using an erecting prism etc.

[julianh72]

Huh?

According to SkySafari, Jupiter rises at 8:17 pm in Brisbane tonight (14 January - 9:08 pm or so for the Southern states), and transits at 1:49 am in Brisbane (2:49 in Southern states), so definitely viewable in the mid-late evening.

[julianh72]

I suggest you start with the two eyepieces you have before buying ANY new ones.

You've probably got something like a 25 mm (low power), and a 10 mm (medium-high power), or something similar. They won't be great eyepieces, but they should complement the telescope reasonably well. (There's not a lot of point in buying $200 eyepieces to use with a $100 telescope.) The existing eyepieces should allow you to get reasonable views of the Moon, Jupiter, Saturn, etc. The low power eyepiece will probably be "easier" to use (more eye relief, bigger exit pupil, etc), so I suggest you use that one first. (You'll probably find that it's the eyepiece you use most of the time anyway.) The 10 mm may give a dim view under even good viewing conditions, and you will probably find that you need to place your eye "just so" (absolutely on-axis, and very close to the eyepiece) to get a good view.

If you're struggling to get a clear view of Jupiter at night, you might find it easier to experiment in daylight hours, targeting a distant feature, such as a building or tree on the horizon. It's generally a LOT easier to work out which way to adjust the focus and so on in daylight, when you can see what you're doing properly. (And you don't need to wait for a cloud-free night, or for the target to get high enough in the sky!) If you can't get a decent image in the daytime, there is something very wrong with your telescope and / or eyepieces, and it won't perform at night.

Once you get a good view with the low power eyepiece, try the high power on its own, then maybe a Barlow with the low power, and finally a Barlow with the high power. You will almost certainly need to refocus a bit each time you change the eyepiece set-up. Chances are that if seeing conditions are good, you will get an "OK" view with the high power eyepiece on its own, but it will look pretty ordinary if you try to use the Barlow and high power eyepiece together under any but the every best seeing conditions. Any combinations that won't yield a good image in the daytime are probably not going to be much use at night.

When you're ready to try Jupiter again at night, start with the low power eyepiece, and don't use any of the Barlows or erect-image accessories. Bring it to focus, and you should be able to clearly make out the disc of Jupiter. With a small telescope and low power eyepiece, it might initially look like a small yellowy-white disc with no obvious bands, but it should be well-defined, and you're making some progress. You should also be able to see several of the moons (up to 4) as points of light - they look like stars, except that they're in a row, and pretty obviously associated with Jupiter rather than being random background stars.

If the image is reasonably stable with the 25 mm, try the 10 mm - it will be quite a bit dimmer, but you should be able to see a bit more colouration and detail. If the image in the 25 mm is shimmering and wobbling all the time, it will just look worse as you increase the magnification, so you're probably better off giving up on the planets for that night, and try looking at some of the bigger targets that are best seen at low power / wide angle, like the Great Orion Nebula.

Hope this helps!

[Jemmo]

Very helpful Julian it's going to be cloudy for a week now lol but I'll try again when it gets better.
If I was only going to use the newt scope I wouldn't bother with different eye pieces. But I'm picking up a 10" dob on sat that comes with no lenses so I want to get 2 decent ones for it instead of the cheap ones I have now

[raymo]

Sorry about my poor old brain's stuff up.
raymo

[Jemmo]

Very helpful Julian it's going to be cloudy for a week now lol but I'll try again when it gets better.
If I was only going to use the newt scope I wouldn't bother with different eye pieces. But I'm picking up a 10" dob on sat that comes with no lenses so I want to get 2 decent ones for it instead of the cheap ones I have now

[Jemmo]

I was just playing round with my newt and put the collimating laser in it just to check. And the main sight mirror is out a bit I only collimated it last week but maybe that has something to do with not a great picture of Jupiter the other night

[barx1963]

Definitely not. If you are seeing a black spot in the middle of a disc, it is definitely a focus issue.

Malcolm

[Jemmo]

I did manage to lose the dot and I just got a orange dot.
I'm guessing it being windy and out of collimation wouldn't of helped