Checking out Jupiter

[Sconesbie]

Hi everyone.

Tonight I was checking out Jupiter and I could see some of its moons. Well, I presume they were. There was two either side of it and I understand it has six in total.

Anyway, my question is this. The view was ok /clear enough looking through both a 10mm and 25mm eyepiece on their own. When I used the 2x Barlow lens with the eyepieces it made it very blurry and no matter how I tried, I could not focus it. All I got was a blur of white with some red and green through it. One was ok through the Barlow (I think it was the 25mm) but the 10mm through the Barlow was useless.

Is this normal?

[barx1963]

Scott
Well done on the observation! Jupiter at current count has 67 known natural moons, however only 4 would be visible using amateur gear. The 5th largest moon is Himalia which is only 170km in diameter and has an apparent magnitude of 14.6. Theoretically possible with a large dob, but it is alose to the planet so very hard to see. Most likely beyond the 4 Galilean moons what you saw were stars in the vicinity.
What you are seeing with the barlow is quite normal. As you increase the power, you are also magnifying any turbulence in the atmosphere that degrades the image. This is most noticeable with bright objects such as planets. I would suggest the 10mm and barlow combo may be pushing your scope to its limits.
Having said that, still give it a look from time to time, you may strik one of those rare still nights when it does give a great view.

Malcolm

[OzStarGazer]

Hello,

Not all nights are the same, as Malcolm said. I can focus with a 2x Barlow and a 10mm when the conditions are favourable (I could even see the stripes yesterday, although not very clearly because of the brightness), but I haven't been able to take photos I like yet. There have been nights though when the turbulences were really strong.

Good luck!

[Sconesbie]

It's a bugger as every time I went to adjust the focus, the scope wobbles so I can't focus as clear as I'd like. That said, it's a fair way away so I'm happy looking at what I can so far. I'll try again tonight and keep plugging away.

Last night wasn't that "black" in the sky either so maybe that's another reason. It seemed very hazy for some reason.

[OzStarGazer]

I am a newbie too so my knowledge is limited, but because you mention "colours" with the Barlow - is it an achromatic lens? (I think most Barlow lenses are achromatic, but I am not sure.)

[glend]

Scott what type of scope is it and does it have a fan? There are things that can be done to improve image stability, that are not due to atmospheric issues. Are you observing over anything like a house roof?

[Sconesbie]

It's a reflector scope. 114mm.

No fan on it but I am looking over my next door neighbours house which has a tin roof. Would the heat off this make a difference? It has been a warm few days of course.

Tonight's viewing was a bit better and I could faintly make out the lines across Jupiter. The moons were different tonight too. Weird but interesting.

I need a darker night, darker skies. I need to go bush I reckon.

[brian nordstrom]

:) Scott, its like everything in life , 'the more you use it the better you will come at using it' , eg. your eyes :eyepop: .
You will find you will see more and more on Jupiter the more you observe it and your 114mm will show plenty with a little patience .
Brian.

[OzStarGazer]

Maybe a colour filter would also help. (Filters don't make an image sharper, but they do bring out details.)

[Sconesbie]

Thanks. I'll keep looking, that's for sure. It's not beating me.

What colour filters would you use? I found something online the other day with eye pieces and coloured filters in a nice case. Was cheap too. I bet I can't find it again. I can't recall the website, Grrr.

[OzStarGazer]

They gave me this link here some time ago. If you scroll down you'll find all the colour filters and what they do:
http://www.lumicon.com/store/pg/15-LUMICON-Nebula-Filters.aspx

I personally bought a set of 4 from Seben: light green, grey, orange and dark blue. :)

[Allan]

Many people don't realise that you will see more planetary detail in a suburban environment, or when the moon is shining brightly, than at a dark sky site. In a bright environment your pupil doesn't dilate as much, so the colour sensitive cones receive a larger percentage of the total light entering your eye. When your eye is fully dilated and all your rods are working, the percentage of light going to your cones is reduced. Hence, you are more colour receptive in a bright environment and can see more colour detail in the planets.

Daniel Mounsey is a well known planetary observer in the US, and he often says the best time to view planets is during the twilight hour, that's when he sees the most detail. He also observes with some ambient light on when he is at a dark spot. He also doesn't use filters, but has done some interesting work on using different eyepieces for the different planets and the moon that helps bring out more detail.

[barx1963]

I agree
One of the best views of Jupiter I have had was at a Snake Valley camp a couple of years back when I was keen to try out my new 10mm Ethos. Just after sunset I had a look at Jup as it was the only thing visible and it was awesome. Lots of details easily seen and nice and clear and steady.

Malcolm

[OzStarGazer]

Well, Scott, last night I had problems focussing on Jupiter too - I think because the halo of the moon was so large and there were also some turbulences... See, not all nights all the same!

[glend]

I had a look at Jupiter through my small scope (130mm newt) and was able to focus ok. I was running a light shield on the front which helped keep some of the stray moon light from bouncing around in the tube. Could easily see the band definition and the four major moons . It helps to use good eyepieces.

Be aware that these very hot days result in heat thermals rising off the earths surface for hours after dark and this can make objects twichy or fuzzy. Best approach is to wait a few hours until it subsides.

[OzStarGazer]

From my balcony Jupiter was just between the moon and its halo and a street lamp, well, at least when I was watching... :( I do intend to buy a light pollution filter very soon (for my birthday), then it will be better. I could sort of see the stripes and the moons, but it was not really well focussed (not like in the previous nights) and there was a huge beam cutting it through, or maybe it was just a reflection on the mirrors of my telescope. I had never seen that reflection before (and I watch Jupiter almost every night!). It was a bit better with a filter, but not much.

[Sconesbie]

I'll keep plugging along. The last three nights have been interesting. I've seen moons in different spots each time. I'm not getting frustrated by any means. The heat on the earth was quite visible through the scope do maybe a later start for viewing is on the cards. I don't care really, as I'm enjoying looking.

Thank you for your comments though. Always good to read and plenty of help.

[barx1963]

Not sure a light pollution filter is much help with Jupiter. They are mainly for improving contrast so you can pick out faint fuzzies in light polluted sky, a bright object will still be bright.
"Beams" cutting into the image are more likely direct light from streetlights or at this point in time the moon getting into the scope.

Malcolm

[OzStarGazer]

Thanks, yes, I understand Jupiter will still be bright, but I was thinking that the filter would make the background darker and for example there would be no unwanted beams anymore. It was the first time that I saw the beam though, so it doesn't happen so often. But yesterday the background was really bright and fuzzy and sort of pinkish/light violet! And it looked sort of "pixelated". I think it was more because of the moon than the street lamp because the street lamp is always there. From here the halo was at least twice the diameter of the moon...