Looking at Saturn

Sconesbie (Scott) · #1 20-04-2014, 09:46 PM

Good evening. The other night I found Saturn. Very proud of myself I rushed in and made my wife and children come and have a look. They were like "oh, I see. Very nice". Then went back inside. Their loss.

Anyway, my question is:

My scope is 4" skywatcher, 900mm, on eq2 mount. When I was looking, it just looked like a white ball with one white ring around it. I can't remember what size eyepiece I had in (maybe 12mm) with 2x Barlow. Is that normal viewing for Saturn? If it is, that's cool and I'm still happy with what I saw. If not, please help.

Terry5 (Adrian) · #2 20-04-2014, 11:13 PM

Hi Scott

I saw Saturn for the first time tonight and had a similar experience. I have a 12 inch dob with a 17mm delos eyepiece in a 2.5 x powermate. I was able to see a separation between the planet and the rings and also what appeared to be a couple of lines in the rings. Still very white.

Adrian

Sconesbie (Scott) · #3 21-04-2014, 10:11 AM

Same. There was a gap between the rings and Saturn but I couldn't see a separation in the rings themselves. Seems like it's standard to just see white. I don't really mind as I'm happy to see it and I'll head back out as soon as I can to look again. It's raining here in Northern Tassie so that means tonight is out. Unless it clears.

Might go fishing instead.

astro744 · #4 21-04-2014, 10:53 AM

Colours are subtle in astronomy. You will find the colour of Saturn to be more yellow with a subtle brown band across the disk. The main gap in the rings is the Cassini division and can be observed in a 60mm telescope so you should be able to see that also.

Good seeing is what is required and well collimated optics. Above all some observing experience, so keep at it as each night is different.

Camelopardalis (Dunk) · #5 21-04-2014, 12:29 PM

Be happy...but keep at it with Saturn, there is more to see with better conditions. Last night, in iffy conditions, the Cassini division was flicking in and out of visibility in my 4". There is some faint banding, and shading in the rings, and the moons dance around in a much different pattern than those of Jupiter. Through its orbit, the tilt of the rings changes as we see it.

Saturn and it's rings certainly have majesty, but it's not as dynamic or as bold as Jupiter or Mars from a night to night perspective.

Also, different peoples eyes perceive different things...I definitely see a pale sandy colour, and the darker more browny band was visible last night in my bigger scope. The rings are more grey to me.

omegacrux (David) · #6 21-04-2014, 06:31 PM

How's the light pollution there ?
Might have to go for a drive there , I don't think I've been to Legana , Tas is so vast

Sconesbie (Scott) · #7 21-04-2014, 06:39 PM

It's not bad David. We're only about 10mins from Launceston so miss the bright lights etc. I've got street lights out the front but they don't seem to bother me much in my backyard. There are places where you could go to avoid the light altogether I reckon though I've not really looked that hard. I'll have a look around and let you know. You're not too far away really. I've met another member who lives around here too. Maybe good to meet up one night as a group of us? I could learn heaps I reckon.

omegacrux (David) · #8 21-04-2014, 07:08 PM

Cool I'm up for it I like meeting other IIS members
I'll bring a 10 dob and the ed80 , and a bunch of eps for you to try !
I know another member near me who would probably come

David

Sconesbie (Scott) · #9 21-04-2014, 08:12 PM

Sounds good. I'm only new to astronomy so keen to try different things and get new views. I'm wanting to buy a dob too. Hopefully an 8 or 10" goto later in the year. Pending budget and sign off from the treasurer.

Steffen · #10 21-04-2014, 08:25 PM

Yep, visual astronomy is very much unpredictable, a bit like fishing.

Tonight is a particular tease here in greater western Sydney — transparency is pretty much absent (veils of high cloud), but the air has moments of great stillness. I'm looking at Mars through my 6" Mak at the moment with a 5mm LV eyepiece (360x)! I don't get that very often here.

Cheers
Steffen.

omegacrux (David) · #11 21-04-2014, 09:18 PM

If you can't stretch to a 10 , you would still be happy with an 8
They are still a very good scope I have had a solid tube 8 skywatcher , sold it for a big acro 150x750 , backwards step imho
You can see a hell of a lot with an 8in dob compared with what you have now
Someone smarter than me can tell you how much more % light it gathers , a lot

David

noeyedeer (Matt) · #12 21-04-2014, 09:23 PM

mirror squared / by other mirror squared

8^ = 64 / 5.9^= 34.81

=1.84 times the light gathering, so 84% more light compared to the acro ..going from the 8" dob to your acro you lost nearly half of your light gathering power

or 100/64 = 1.56 if comparing the dobs...and 56% more light between the dobs

MortonH · #13 21-04-2014, 09:58 PM

Seeing is everything in planetary observation. And patience. The temptation is to push the magnification higher and higher because you want the image to be bigger, but usually this makes it worse. Small and sharp is better than big and fuzzy. You also need to realise that the atmosphere is quite unstable. You will normally get only brief moments when the image is very sharp as the air steadies for a second or two. So you need to be patient and wait for those moments. When I started in astronomy I quickly gave up on planetary observation as I never seemed to get a decent view. But I knew nothing about seeing conditions and all the other factors that affect plenetary viewing.

You also need to be aware of your local environment, i.e. are you looking over buildings that are giving off heat plumes, etc? My apartment has two balconies, facing East and West. The Westerly one can give stable views but the East balcony looks over a very busy road and is pretty unstable. The maximum magnification I get in the East is about 150x, while I can easily go over 200x on my Western side.

Wavytone · #14 22-04-2014, 01:01 PM

Quote:

Originally Posted by noeyedeer

mirror squared / by other mirror squared

8^ = 64 / 5.9^= 34.81

=1.84 times the light gathering, so 84% more light compared to the acro ..going from the 8" dob to your acro you lost nearly half of your light gathering power

or 100/64 = 1.56 if comparing the dobs...and 56% more light between the dobs

Hi matt, yes a 50% difference is noticeable visually, however the magnitude scale is logarithmic (as are our eyes, too) and you might like to look at difference in limiting magnitudes as well.

Put it another way - after using a big scope it can be a tad amusing to realise what you can actually see in a 8x50mm finder when you look closely in dark skies.