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First views of Jupiter & Saturn successful - any tips?


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Hi all

Well, I woke up at about 2am this morning and couldn't get back to sleep. By about 3am I'd given up trying and decided to head out into the garden to see if it was worth getting the 'scope out. I could see what appeared to be two bright 'stars' and hoped they'd be Saturn and Jupiter. I smuggled the 'scope out of my bedroom, almost without waking my wife and was proved right.

I easily managed to make out Jupiter and three moons. I could just about make out a band on Jupiter, but otherwise it was just a very bright disc. I managed to make out the rings of Saturn which actually made me chuckle, startling a passing hedgehog. Then the sun started to come up and it was game over.

Now, I'm really happy with what I saw - first time for me seeing both of those planets with anything other than the naked eye. However, me being me, I'm now thinking about how I can improve things for next time and I have a few questions that I hope some of you folks might be able to help me with.

1. Jupiter seemed *very* bright. Its moons were pin-sharp dots, but it seemed blurry round the edges. I wonder if this was down to its brightness? Or maybe just the seeing? Would I see more detail with a filter?

2. How can I tell which moons of Jupiter I saw?

3. I saw something near Saturn that *might* have been a moon. Although I suspect it might well have been a faint star. Is it likely to have been a moon or do I have no chance with my small scope? How would I know? (Most other stars weren't visible due to the sunrise at this point so I didn't really have a reference)

Thanks!

 

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Stellarium and other software and apps will show you which moon is which on both Jupiter and Saturn.

Up to 4 moons are visible around Jupiter with amateur scopes, as many as 5 around Saturn with your scope but all apart from Titan are quite faint so will take practice to see. Their positions change night to night and even hour to hour with the Jovian ones.

The low position of these planets in the sky does not help with sharp views and seeing the best details I'm afraid.

What I'd suggest is to keep observing them and for as long as you can each time. With planetary observing, as in most other visual astronomy, "the more you look, the more you will see" is very true. Your eye will gradually tease out more details during the patches (often very short) of good seeing.

You will find that Jupiter looks better at slightly lower magnifications than Saturn. 120x - 150x with your scope for Jupiter and possibly up to 200x for Saturn. This will vary with the conditions though so be guided by those.

Hope that helps a bit !

Edited by John
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Sounds fun @Bongo.

What scope do you have and what eyepieces/magnification were you using?

Even now, the planets are quite low down so there is a limit to what you can see due to the thick atmosphere.

There are various apps which you can use to find out which moons you saw. I use SkySafari but Stellarium is also good, plus plenty of others.

Here are two screen shots showing the Moons at 3.30am. I suspect it was Titan you were viewing as that is the brightest Moon of Saturn. Depending on your scope, the orientation will either be left/right reversed (refractor/Mak/SCT) or upside down (newt) from these.

 

 

1E4F030C-9FB9-4FE1-9C4E-9E0A29CD3676.png

83B51A1D-515A-4BA8-8511-3DC8E5856B73.png

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1 hour ago, Stu said:

Sounds fun @Bongo.

What scope do you have and what eyepieces/magnification were you using?

Even now, the planets are quite low down so there is a limit to what you can see due to the thick atmosphere.

There are various apps which you can use to find out which moons you saw. I use SkySafari but Stellarium is also good, plus plenty of others.

Here are two screen shots showing the Moons at 3.30am. I suspect it was Titan you were viewing as that is the brightest Moon of Saturn. Depending on your scope, the orientation will either be left/right reversed (refractor/Mak/SCT) or upside down (newt) from these.

 

Hi.

Thanks for the info - very useful. I'm using a BST StarGuider 60º 8mm ED Eyepiece and scope as per my footer.

Titan does seem plausible.

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I was out with my heritage 150 dob from 2am until  about 3:30 am (after putting my new refractor through its paces earlier while the Moon was up ) I had to take the dob out , it was my first proper scope and yesterday was its first birthday 🙂 I got a quick look at Saturn (which, with the poor seeing appeared to fizz like an effervescent tablet with any serious magnification) before it vanished behind the trees, Then switched to faint fuzzy searching, and having finally managed to see the Dumbell Nebula which is somewhat of a challenge in my light polluted back garden, , I spent the last 30 minutes or so until the sky brightened nudging the dob to keep Jupiter in view.

My 8mm BST was too much mag.for the conditions (94x), the seeing was not good enough, but the 12mm gave a decent view ... that's just 63x in the dob. Still, the orange banding was visible, and sitting watching for a sustained time gave brief glimpses of structure and finer detail. As you saw, Jupiter is bright, you can be dazzled by it when your eyes are dark adapted, but give it some time and you see more as eye and brain adjust. If you have a Moon or variable density polarising filter , you could always try that , or even the slightly mad stopgap of sunglasses ...

I didn't use any filters last night , but I have tried various coloured  filters before. Some people like them , some see no point. To find out which I was, I bought a very cheap set of half a dozen no-name Far East ones for about £15 from Amazon, and found when Mars was well placed in the winter the filters really helped increase the contrast of the surface features, so I bought some better quality but still fairly basic ones second hand . I've not had the chance to try any on Saturn & Jupiter yet.  Here are a few links with information about filters, there seems to be a fair bit of variation in what different people say are useful for particular situations, I think it may well be heavily dependant on both your telescope and your eyesight. A relatively small aperture 'scope like mine and yours isn't going to work well with strong filters which cut a lot of light out ... the dark red filter which was included in my cheap set was useless in the 'scope, just too dark an image, but is doing sterling work taped onto the front of a small torch to make it a red light !

https://www.firstlightoptics.com/flo-guides-colour-filters-to-improve-lunar-and-planetary-visual-observing.html

https://astunit.com/astunit_tutorial.php?topic=filters

https://sas-sky.org/wp-content/uploads/2011/09/SAS-The-Use-of-Astronomical-Filters1.pdf  (I think they put some images in the wrong paragraphs there)

https://agenaastro.com/articles/guides/visual-and-imaging-filters/choosing-a-color-planetary-filter.html

Heather

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Did you allow time for the mirrors to acclimatise? Even with summer temperatures I allow at least 30 minutes and I keep the telescope away from buildings or concrete to minimise heat haze.

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Well...

What magnification did you use? I see that your telescope comes with two eyepieces, I guess the higher powered one? It is still not enough for details. You have aperture to see quite a bit on Jupiter, and some nice showing of Saturn, but before you expect that:

- your mirror has to be acclimatized, too much temp difference and you will have thermals,

- your telescope has to be collimated well, especially for planetary viewing,

- you have to pump up the mag a bit, I feel 100x and upwards. I use 114x on a 71mm refractor, you can certainly do 120x on your telescope and tracking will not be a problem.

- you have to wait until the planets are somewhat higher in the sky, below 20 degrees is a no-go (will be a mush due to dispersion and seeing).

The trouble with this hobby is that the planets and the Moon are are at their lowest  and the nights are at their shortest when it is comfortable to sit outside and one is usually on vacation.

August, September and October should be pretty good for Jupiter.

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On 23/06/2021 at 10:24, Stu said:

Sounds fun @Bongo.

What scope do you have and what eyepieces/magnification were you using?

Even now, the planets are quite low down so there is a limit to what you can see due to the thick atmosphere.

There are various apps which you can use to find out which moons you saw. I use SkySafari but Stellarium is also good, plus plenty of others.

Here are two screen shots showing the Moons at 3.30am. I suspect it was Titan you were viewing as that is the brightest Moon of Saturn. Depending on your scope, the orientation will either be left/right reversed (refractor/Mak/SCT) or upside down (newt) from these.

 

 

1E4F030C-9FB9-4FE1-9C4E-9E0A29CD3676.png

 

Just a quick heads-up that the image for Jupiter and its moons is a bit misleading - at 3:30, Ganymede was actually behind Jupiter, so would not have been visible. The moon to the right of the planet would have been Io - though you may have seen it on the left in your scope as the image is reversed

Screenshot_20210625-092023.jpg.4fc93f4b18c137db7e92e94921eed771.jpg

On my Android phone, I use the "Moons of Jupiter" app - as well as showing the positions, it gives advance notice of events such as transits or entering/leaving shadows etcScreenshot_20210625-091522.thumb.jpg.33a04d3d95ca8f3fe01eac444927efd9.jpg

 

 

Edited by Gfamily
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  • 2 weeks later...

Congratulations, first and foremost.

My favorite site for tracking the moon of Jupiter is from Sky & Telescope online here: https://skyandtelescope.org/wp-content/plugins/observing-tools/jupiter_moons/jupiter.html

The "star" near Saturn may well have been Titan. Again, a Sky & Tel webpage for Saturn: https://skyandtelescope.org/wp-content/plugins/observing-tools/saturn_moons/saturn.html

(Note that for these, you can choose the view depending on your kind of telescope.)

I agree with the posts above about letting your telescope adjust to the environment and also keeping the dew off of everything.  Jupiter should be a pretty easy target to view clearly with your 5-inch dobsonian. But the dob has a big tube, so it may need to acclimate a bit longer, but others have more ken than I witih that.

In any event, you had a good session! Next time, go for some stars. Where you are, the Big Dipper and other stuff to the north shoudl be a rich field of discovery. We had a chat here about Mizar-Alcor, the easy visual double in the handle. Your telescope should show some surprises there. Also, Polaris may surprise you.

 

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On 25/06/2021 at 05:43, Bongo said:

Some great info here, folks. And certainly some stuff to try for next time, which is what I wanted.

Thanks very much, all!

I looked up your telescope. I was a bit out of focus myself by the label "dobsonian." Usually, it refers to a larger mirror, 8, 10, 12, inches or more. But, of course, John Dobson was equally famous for his simplified mount. He demurred against all praise and said that it was just a lazy susan. I suggested that your telescope's tube might need extra time to adjust to the ambient temperature. That is true, but yours is not a large tube. You have a nice 5-inch Newtonian reflector. 

1983644261_LightbridgeMini130.jpg.fcb3c817b4f1ab38ee28297b711a234e.jpg

I know that Meade calls it a "Dobsonian" and they are not incorrect in that this is the "lazy susan" mount. Myself, I would call it a tabletop Newtonian with an Alt-Az (altitude and azimuth) mount. It is a nice scope. It should reveal a wide range of targets, from planets, to double stars, to clusters. 

Keep us informed as you discover more in the sky. There's a lot out there.

Trust your own instincts. I read back through the responses and I am not going to engage in side discussions but some of the advice was based on personal experiences that might be different from your own. 

Am I correct that you bought the telescope used as-is and you did not get the 26mm and 9mm eyepieces that it comes with? (The Meade website says that the model is discontinued. So, I assume that you bought it used.). The arithmetic for magnification is TELESCOPE divided by EYEPIECE. 

Your telescope's focal length is 650mm and 650/8 = 81.25. So, that's a nice magnification, very up-close. As noted by others, you can do more. There are some rules of thumb. A lower limit could be Aperture times 0.2 (or divided by 5), so that your lower limit could be 26. An upper limit could be 10 times that. But effectively would be limited by the actual sky (light pollution, haze, etc.), so maybe 130X before you lose resolution and start seeing your own eye floaters. But it depends on you, what you see when you use your telescope.

Astronomy can be an expensive hobby and we all are willing to spend your money for you. If you are looking for other oculars ("eyepieces") ask around and take it all with a grain of salt.  A lower power (32 mm or 40 mm) added to a 2X Barlow may give you some other options. The 2X Barlow will double the effective magnification of your present equipment. The lower power will give you a wider view of things like the Moon and the Pleiades. Coupled together a lower power and Barlow will give you a range of viewing options. But overall, reading is the thing. Make use your local library and used bookstores as well as website discussion boards like this one. Do you have a local club in your area?

Whether you get more kit and gear or not, your BST 60-degree 8 mm is a good piece of glass. Enjoy it.

Edited by mikemarotta
grammar
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  • 4 weeks later...

@mikemarotta Thanks for all that. Sorry for not getting back to you sooner - things have been a bit hectic around here.

I think I definitely need to let my telescope acclimatise for longer. I have a bad habit of popping my head out of the back door, spotting a clear sky, rushing for the 'scope and cracking on. Not always the best bet!

To answer your direct questions - I have the EPs that came with the scope, plus the BST 8mm (which I'm very happy with indeed!). I inherited a 3x Barlow, which can be nice with the stock EPs but I've had no luck combining it with the 8mm BST - hard to focus and/or track. Gives options with the other EPs though.

I know that magnification isn't everything, tempting though it seems, but I did wonder whether something like a 5mm BST might work with my scope. Especially considering planetary viewing options in the next couple of months. What do you think?

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12 minutes ago, Bongo said:

@mikemarotta Thanks for all that. Sorry for not getting back to you sooner - things have been a bit hectic around here.

I think I definitely need to let my telescope acclimatise for longer. I have a bad habit of popping my head out of the back door, spotting a clear sky, rushing for the 'scope and cracking on. Not always the best bet!

To answer your direct questions - I have the EPs that came with the scope, plus the BST 8mm (which I'm very happy with indeed!). I inherited a 3x Barlow, which can be nice with the stock EPs but I've had no luck combining it with the 8mm BST - hard to focus and/or track. Gives options with the other EPs though.

I know that magnification isn't everything, tempting though it seems, but I did wonder whether something like a 5mm BST might work with my scope. Especially considering planetary viewing options in the next couple of months. What do you think?

The 5mm BST will work beautifully with your scope, not over powering it in the slightest. But we are at the mercy of the atmosphere and sometimes even 130x is not possible. As others have already said, let the scope cool and spend time at the eyepiece. With some decent skies the 5mm BST will work a treat in your scope. Just make sure the scope is well collimated as well. If the collimation is off you'll never get those fine details on the planets, not matter how hard you try.

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4 hours ago, Bongo said:

@mikemarotta Thanks for all that. Sorry for not getting back to you sooner - things have been a bit hectic around here. 

...  plus the BST 8mm (which I'm very happy with indeed!). I inherited a 3x Barlow, which can be nice with the stock EPs but I've had no luck combining it with the 8mm BST - hard to focus and/or track. Gives options with the other EPs though.

Well, you know, you can multiply or divide but 3XBarlow with an 8mm ocular is like using an (8/3 mm) eyepiece: like 2-2/3... pretty tight. So, focussing will be touchy. But, yes, the 3X gives you options.

The important thing is to keep at it. Go out when you can. Read went you cannot go out. If I may ask, what books do you have? Do you read any other web discussion in addition to this one? We can all recommend books, lots of books, trust me on that. You will need the stargazer books like Turn Left at Orion, but also telescope books like Philip S. Harrington's Star Ware. I just borrowed S. Barlow Pepin's Care of Astronomical Telescopes and Accessories from my local library. I also cruise the used bookstores and leaf through many just to see what speaks to me. I found a recent edition of a standard one-year university text at a good price. But I am a bibliophile and I prize my copy of a book by Henry Norris Russell. In the UK you have a surfeit of books by Patrick Moore and even a series edited under his direction. We all have our favorites, but it is like eyepieces: your eyes are not mine and the book that works well for me may not be friendly for you.

Edited by mikemarotta
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On 23/06/2021 at 11:49, Bongo said:

Titan does seem plausible.

Titan is nearly always visible in any scope, after that Rhea, the second largest moon can be seen with apertures 100mm and upwards, a 200mm will reveal another three/four moons.

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Jupiter and Saturn appeared for me last night. Some great views but as soon as I went over 100x on 6"sct then I started to lose things. At 93.75 x 4 moons of Jupiter were shining VERY bright for me all nicely lined up. 

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On 03/08/2021 at 19:41, mikemarotta said:

You will need the stargazer books like Turn Left at Orion, but also telescope books like Philip S. Harrington's Star Ware. I just borrowed S. Barlow Pepin's Care of Astronomical Telescopes and Accessories from my local library.

Yep, I got a copy of Turn Left at Orion. To be honest, I've only had a brief preliminary flick through so far. Have to make a more concerted effort!

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On 04/08/2021 at 10:42, Starslayer said:

Jupiter and Saturn appeared for me last night. Some great views but as soon as I went over 100x on 6"sct then I started to lose things. At 93.75 x 4 moons of Jupiter were shining VERY bright for me all nicely lined up. 

I'm so jealous! After my initial viewing I mentioned in this post, I've been plagued by cloud cover. Surely there must be *some* clear sky in the next month or two! <crosses fingers firmly>

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26 minutes ago, Bongo said:

I'm so jealous! After my initial viewing I mentioned in this post, I've been plagued by cloud cover. Surely there must be *some* clear sky in the next month or two! <crosses fingers firmly>

haha. We had the same again last night.  Forecast not so great now though.  🤔

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On 05/08/2021 at 15:24, Starslayer said:

haha. We had the same again last night.  Forecast not so great now though.  🤔

Looks like a few decent nights on the way though!

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Hi,

I'm so glad I'm not the only one with this question! 

Last night was the first time I've properly had my Heritage 150p dob out properly. Jupiter was SO bright I just couldn't resist!

I located it in the 25mm eyepiece, and then switched to the 10mm (finding that focussing without my glasses on was better).

In the 10mm eyepiece I could see something like the below (my spectacular mockup using the doodle tool in my photo editing app 😂). Jupiter was still small, moving fast across the FOV, and VERY bright, but I could see a band! Your description sounds about the same @Bongo.

I could also see two moons (Ganymede and Callisto, I think going by my comparison against Stellarium.)

Jupiter was quite low in the sky at 12:30am, so I know I was dealing with a lot of atmosphere, and I live in a Bortle 6 area. I found myself wondering what else I could do to get a better view with some more details.

I'm going to make a light shroud for the scope, but I was wondering about filters and/or other eyepieces as well. The Baader Hyperion mk IV zoom is on my wish list, as I know that will scale to a bigger scope. I've noted down a few things from the comments in the thread.

Have you been out again @Bongo

Here's to clear skies!

MiladyB x

Pixlr (1).jpg

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