Novice Advice

[davidhorton]

Hello everyone, 

Recently, I purchased the Celestron NexStar 102SLT and am hoping for some very simple advice!

This past Thursday (7th January 2016), in Leigh-on-Sea, Essex we had an incredibly clear sky and I spent an hour or so outside looking at various constellations from around 10pm, when researching I found out that Jupiter would be high enough to see around 5am. When I returned at 5am, Jupiter was easy to spot, I aligned my finderscope / eyepiece and successfully found Jupiter (a white dot) and it's four moons (very faint dots). 

Obviously, I was very pleased as a beginner to be witnessing my first intentionally found planet. But was curious how I could view the planet in more detail, moving away from the bright white dot and seeing the planet's colour. 

On that night I was using my Celestron 9 eyepiece, my plan on the next clear night is to test my second eyepiece the Celestron 25.

Does anyone have any recommendations on the best solution to see Jupiter?

I'm sure this question is very basic, but when researching online I found all the information quite overwhelming! 

Many thank!

David

[happy-kat]

Hi

The 25mm will give a lower magnification than the 9mm.

Telescope focal length divided by eyepiece size will give magnification.

Jupiter is very low in sky and not great viewing really. It will be better once bigger.

[ronin]

Would have thought the 9mm would have supplied more then a white disk, you had just under 75x.

The 25mm will be smaller and so brighter, the final image is smaller and all the collected light is getting squeezed in so more intense.

Still think the 9mm should have been better.

Really means you could need a better eyepiece.

Would suggest the BST 8mm, except it is close to the 9mm. If however the problem is the performance/quality of the eyepiece then the BST should deliver better.

Another option is the Altair Lightwave at 6mm (£45).

From what I read it seems the same as the WO SPL 6mm (may not be but specification is the same) and that has a good reputation.

Actually considering one myself as it plugs a bit of a gap.

As it sounds like the present image is too bright you will need a bit more magnification, so the 8mm BST or 6mm Altair are I would say the better options.

Tempted to say the 6mm Altair.

[laudropb]

At 75 x I would have thought you would have seen the Equatorial Belts. Perhaps the seeing was not good. Also sometimes you have to spend a bit of time viewing Jupiter. Often the longer you view the more detail you will see.

[Putaendo Patrick]

Congratulations on your first foray into astronomy! Your Nexstar is a very nice short-tube refractor which is excellent for general observation. It is, however, not the ideal scope for high magnification planetary viewing.

The focal length of your scope is 660mm. Given the formula supplied by Happy-Kat, your 9mm eyepiece will give a magnification of x73. The 25mm will give x26. When you use this next, I would suggest targets such as the Great Nebula in Orion or the Pleiades star cluster.

In the longer term, for lunar and planetary observation, you might consider adding a 6mm eyepiece which will give you a magnification of x110.

[Moonshane]

With bright objects especially planets you need to look for a few minutes and eventually your eyes will adapt and you'll see more.

Currently you did the right thing observing in the morning but later this year Jupiter will be high in the evening

[Lowjiber]

All good advice above.

Just keep in mind that any target (especially Jupiter & Saturn) is difficult, at best, when it's below about 40^o above the horizon.  You're simply trying to look through too much atmosphere.

That's not to say don't practice, but just temper your expectations a bit.

Clear, Dark Skies

[Stu]

I would agree that whilst it's not an optimum scope for planetary observing, you should still be able to see the two main equatorial belts on the planets surface.

Sometimes the seeing conditions are not very good and that tends to blur out any detail. Try observing on different nights to catch the better conditions, plus as Shane says, give it time. Spend some time looking and you should find your eyes adapt and more detail becomes visible. You also catch the moments of good seeing if you spend more time looking.

The scope should cool quite quickly, but it's still worth giving it 15 to 20 mins if taking out of a warm house, the views will improve.

[davidhorton]

Thank you for all the extremely insightful advice (happy-kat, ronin, laudropb, Putaendo Patrick, Moonshane, Lowjiber, and Stu).

I am looking forward to the next clear, dark night (next Tuesday, hopefully) to get back out and spending more time looking at one area rather than constantly moving around the sky. Patience!

Regarding the advice about allowing time for your eyes to adjust - when Jupiter (white dot) was in focus, not a blur; the size was quite small. Would you recommend increasing the magnification, in turn blurring the image in hope my eyes adjust and the blur is not to obscure?

Thanks again

[brantuk]

Your highest useful magnification specified for this scope is 240x but I usually work to 75% of the stated max. I would think you can squeeze 150x to 180x out of it to see a bit more detail. A decent 4mm eyepiece might help - but all the above comments about training the eye to look, choosing a good elevation, telescope type and purpose etc still apply. A good planetary scope usually has a much longer focal length, typically starting around one meter.

[Ricochet]

When you say increase the magnification you aren't talking about adjusting the focuser to make the image appear larger are you? The focuser is just to focus, to change magnification you need to switch eye piece and so long as you don't exceed the maximum magnification for your scope and seeing conditions the image shouldn't really be something you think of as blurred.

Magnification is the focal length of your scope (660) divided by the focal length of the eyepiece. Both your scope and the UK atmosphere will limit you to 200X so eye pieces longer than 3.5mm or 7mm if you get a 2X barlow would be a good match for your scope.

[barkis]

One can sometimes feel a bit deflated the first time you turn their telescope skywards.

There are so many factors that are involved regarding the scopes performance,

and usually, none of them are the scope itself. Barring the very odd exception.

Yours is a quite good instrument, so be patient, and things that matter will come to you in due course.

I can add to Ronin's post inasmuch as eyepieces vary a great deal in quality, and many a good telescope has been diminished by 

poor quality epepieces, but bear in mind, that very good ones are expensive, some more that the price of your telescope.

Seek advice when you feel you need to, and plan what you would like to add to your kit, don't just spend and hope.

Lots of knowledge and skill is resident on SGL, and It's all available if and when you need it.

Good Luck.

[bomberbaz]

Did the scope come with a 2x barlow? That would be a good way of getting more out of the 9mm eyepiece. (9/660=73 x2 = 146)

Getting close to the maximum magnification for your scope probably but if you do have a barlow and want to try then first get Jupiter central in your 25, then the 9 before using the barlow. Then carefully focus until you have the smallest possible disk to achieve prime focus.

On a good night you will see lots of detail including the great red spot. Obviously if you don't have a barlow then this advice does not apply.

If not then a useful addition would be the 5mm of the same celestron eyepiece (x132) still giving you lots of detail as above. Nice piece of glass for the price.

Steve 

[geministar]

I can easily see two equatorial bands/belts with my Nexstar 127, going up to x214 (and even a tad higher), but I have found it looks nicer at lower mags like x83.  The image seems sharper, the wider view is more pleasing, and the bands are still visible.

They're still grey mind you, but that's another matter which I have had a good response to on SGL!

[happy-kat]

At 66x using a 6mm eyepiece with my ST80 (a smaller similar version (though the ST is even shorter focal ratio) of the OP's 102) I have seen the two main bands on Jupiter. Were they slightly coloured I can't recall.

[Mak the Night]

Jupiter can be mutable depending on conditions. Sometimes it can go from being distinct to a fuzzy white ball as you are watching it. I had a superb view of a setting Jupiter in dusk light last summer. I could even see the Great Red Spot at around 145x magnification. I live in the greenbelt and there isn't much to the west of me except woods and farmland. In fact within ten minutes walking distance is a field often used by amateur astronomers as a dark site. I managed to view it a few weeks later with a different telescope but better magnification at around the same time as it was setting. It looked great for a few minutes (the GRS wasn't visible that day) then as it got lower in the sky it turned into a white featureless blob as I observed it! You may have just had some bad luck with conditions or 'seeing'. 

[russo]

Hi,

I was doing exactly the same thing, at the same time, at the same place, with pretty much the same result.  My telescope is different (SKywatcher Heritage 100p) but everything else was the same.  

My take on the lack of detail was a) not giving it enough time to appear to the eye and there's a lot of light pollution in Leigh and I suspect this washed much of the detail out.

Hope you have more luck next time.

[Mak the Night]

I had a butcher's hook at Jupiter this morning. Unfortunately it was suffering from its infamous fuzziness as the seeing wasn't brilliant. I've got Jupiter to 150x in the past and seen a lot of detail including the GRS. That wasn't one of these times. I started off with 140x then dropped to 86x after an hour or so observing eventually with 65x (all with a binoviewer) and I could make out the two main cloudbelts but although the GRS was in position I couldn't discern it. Ganymede and Europa were easy and I had hoped I might see the transit of Io with the bino's but I think that was a bit ambitious with a 4" Mak lol. My Baader Neodymium filter helped a lot though as did the 'stereo' effect of the bino. 

[bomberbaz]

After making my earlier post I decided to go an take a look at Jupiter.  I am likewise still fairly new,  about 7 months now, with about 50+ hours at the eyepiece.   

I pulled out my ETX 80, 80 mm/400 mm refactor.  I used a Celestron 8-24 zoom eyepiece to take a look at Jupiter.  

At 10:45 pm last night Jupiter was about 15 degrees above the horizon, not the best viewing angle, so I was looking through a lot of atmosphere.    At 5 am, when you looked, Jupiter should have been high overhead, a much better viewing position.

At 16X I could see the bright planet and 4 moons.  

At 50X the planet was still a bright disk.  This is max on this zoom for this scope.

I added a 2X barlow   Now I can go 32 to 100X with this eyepiece.

At about 70X the planet was a bright disk with the faintest hint of the two dark bands fading in an out as the atmosphere boilded in my line of sight.  It was very difficult to find a good focus point as the planet moved in and out of focus, a byproduct of viewing a this relatively low angle.

At about 100X I was able to see the bands but they were still fading in an out.  This was more magnification than I wanted to use for these conditions.   

As noted by laudropb, because the planet is so bright you can benefit from giving your eye a chance to adjust to the brightness as you keep the planet in view in the eyepiece.  Detail that was not there starts to become apparent.  

I was only out for about 10 minutes for this test.   After I put it all away I wondered if the view might have benefited from using my 25% transmission moon filter to cut the brightness of the planet and possibly improve the contrast.   I also have some color filters that I got for Christmas that I may try the next time I am out looking at Jupiter.   The next time I get Jupiter in the eyepiece I am going to give these a try.

Hope that helps.  Give it another try and let your eye adjust for several minutes. You should start to see the bands.

I have found the coloured filters do help depending on the detail you are after. I did a post a long time ago on this after a nights testing but I seem to think the green and blue work the best. Something to try out again I think.

Steve

[Mak the Night]

It didn't look half as clear or as large as this does, but it isn't a bad approximation to what I saw at around 04:30 GMT.

It took a couple of hours for Io to become visible and only then after the transit. The GRS can be seen here but I couldn't make it out this morning. When I have seen it, it is more of a brown colour and it helps if you know where it is exactly beforehand I find. I could see the the white equatorial band sandwiched between the darker brown bands this morning though. The darker polar cloud bands were hinted at also. I find that with patience as your eyes adjust through an observing session you can slowly discern more features. A good seated position helps, and being comfortable at the eyepiece. I've not had many chances to try my new binoviewer but being able to use both eyes was a plus with Jupiter this morning as I found it more natural with an extended observing session. I really do think the Baader Neodymium filter was helpful with contrast as well.

http://www.firstlightoptics.com/light-pollution-reduction/baader-neodymium-filter.html

[Mak the Night]

I have not had a lot of planetary time since I entered the hobby.  Saturn was usually behind trees and the other planets were in the morning whch is not convenient for me during the week.    Clouds on the weekends kill that too.

But as Jupiter has been risiing earlier and earlier it is higher in the sky during the times I have available so I plan to do a lot of experimenting with eyepieces, magnifications and filters.    I am still at the stage where I am learning the equipment I have and I got some new toys for Christmas.

Yeah, you've gotta try out the stuff Father Christmas brought! lol