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Nice views of Uranus and Neptune (Finally)

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#26 Jon_Doh

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Posted 06 October 2013 - 08:09 AM

Thanks Pete.

#27 aa6ww

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Posted 08 October 2013 - 02:44 PM

Saturday night 10-5-2013, I had a nice view of the Planet Uranus with my C14. The seeing conditions were perfect at 5/5, and transparency also. I was out at a small town near where I live, in Wilton Calif. Its in the Orange zone. At about 435x with my 9mm Nagler, I noticed two small moons above the planet in the 11 o clock and 1 o clock position from Uranus. At 558x, using my 7mm Nagler, a few more very tiny moons were starting to come through, even closer to the planet than these two, but they were in and out and in the glow of Uranus. I don't recall the names of these moons. Later on, I checked and Stellarium was showing the first two moons as Oberon to the right, and Titania to the left. One was at mag 14.93, the other at 14.63. I don't recall the names of the other moons but they were in the 15.6 mag range. I was impressed I was able to see glimpses of these dimmer moons but again, they were in and out and I really had to look at them with a dark cloth over my head to really concentrate on what i was seeing.
The planet itself was spectacular. One of my friends said he had never seen the planet so large and vivid ever.
One of the web sites, i think it was Astrobob, was stating that Oberon and Titania were going to be visible this weekend, because Uranus was at opposition from Earth at this time. It seemed to be a very casual comment. In reality, even these moons were very difficult to see. My other observing friends didn't even attempt to locate Uranus to see if they could see the moons in their C11's, C8's, and one with a large 8" ISTAR refractor.
I wonder what the smallest scopes people use to detect these two moons, and if so, what type of darkness conditions were you observing in to detect such tiny dim objects.
Are these moons about as dim and small in the eyepiece as the Planet Pluto, which is in the 14mag range?
Has anyone ever compared Pluto to these moons and if so, are the views similar?
Ive never recognized Pluto but its in a good part of the sky now for me to look for now.

...Ralph in Sacramento

#28 brianb11213

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Posted 08 October 2013 - 04:03 PM

I wonder what the smallest scopes people use to detect these two planets, and if so, what type of darkness conditions were you observing in to detect such tiny dim objects.

With mag. 6.2 skies (significant suburban light pollution) Uranus & Neptune are both visible with minimal optical aid, like 4x20 binoculars. (Colourless starlike points, obviously!) With slightly better skies Uranus should be a fairly easy naked eye object. I could probably see it from home if it was at the zenith instead of not even halfway up the sky when on the meridian.

#29 aa6ww

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Posted 08 October 2013 - 06:14 PM

Sorry, I had a slight error in what I meant to say. I meant to say "I wonder what the smallest scope people have used to detect these two small moons, on the Planet Uranus, and also how dark are the skies used to see them both. I've corrected that error in my original question.


...Ralph

I wonder what the smallest scopes people use to detect these two planets, and if so, what type of darkness conditions were you observing in to detect such tiny dim objects.

With mag. 6.2 skies (significant suburban light pollution) Uranus & Neptune are both visible with minimal optical aid, like 4x20 binoculars. (Colourless starlike points, obviously!) With slightly better skies Uranus should be a fairly easy naked eye object. I could probably see it from home if it was at the zenith instead of not even halfway up the sky when on the meridian.



#30 brianb11213

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Posted 09 October 2013 - 04:04 AM

I meant to say "I wonder what the smallest scope people have used to detect these two small moons, on the Planet Uranus, and also how dark are the skies used to see them both.

Sorry for the misunderstanding.

I've seen four moons of Uranus with 11" SCT. Titania & Oberon were pretty unmissable, Ariel & Umbriel difficult, Miranda invisible. Transparency is obviously important but a really dark sky isn't as the planet itself contributes sufficient glare to affect dark adaptation. The best power to use is probably around 20x per inch of aperture - enough to dilute the sky brightness but not enough to bloat starlike points into diffraction patterns. With larger apertures, reasonably steady seeing is also required.

As to "how much aperture is necessary" - to quote from T W Webb, "Celestial Objects for Common Telescopes":

"Ward has glimpsed the two outer moons, Oberon and Titania, with a 4.3" Wray achr, as Huggins has with 8" achr, and Sadler with a 6.5" mirror. My less acute eye has caught one with 9.3" speculum. Marth has found their visibility not affected by moonlight."

The 19th century observers were of course blessed with skies which were generally much darker than those we have today but this would be offset to a considerable extent by the extra transmission of modern scopes (multicoated lenses and more efficient mirrors: speculum metal mirrors would be only about 50% efficient even when freshly polished!)

Similarly regarding Neptune's moon Triton:

"... held by Dawes with 8" achr, no common telescope of course would touch: though Ward has glimpsed it with a 4.3" achr".

Pluto is of course omitted from the text (discovery over 70 years after the publication of the first edition). It's harder to find than Uranus's moons but probably easier to see as there's (usually) no distracting bright object in the field. This assumes similar observing conditions, but the issue with Pluto for those of us in the northern hemisphere is that Pluto is lurking fairly deep in the southern hemisphere (and will remain there for several decades) so atmospheric absorbtion and poor seeing interfere significantly.

#31 mark8888

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Posted 09 October 2013 - 10:03 AM

Inspired by this thread, I found Uranus tonight for the first time this season. At around 130x in my 7in. scope, in an area of sky with a ton of light pollution (virtually no stars at all visible to the naked eye) it looked like a pale bluish little disk. No moons were visible at that mag as far as I could tell, I believe a nearby object north of it was a star. I tried to jump it up to around 250x, but the seeing and also the horrible light pollution level just couldn't support the view, I couldn'd find the planete again and that was that. But it was exhilarating while it lasted.

It is said that light pollution doesnt matter for looking at the moon, Jupiter, Mars, the bright objects... but would I be right to say that for the dimmer planets it most definitely does affect the view?

#32 brianb11213

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Posted 09 October 2013 - 10:27 AM

It is said that light pollution doesnt matter for looking at the moon, Jupiter, Mars, the bright objects... but would I be right to say that for the dimmer planets it most definitely does affect the view?

I would say that having Uranus in the field of view of my 11" SCT reduces the magnitude limit I am able to reach by around 1.5 ... similar to the moon a couple of days either side of full, for a "dark field" object. Really severe light pollution is of course going to have an effect. But then so does slightly inaccurate focus, poor seeing, ... and most of all the observer's experience in viewing objects close to the visual limit. A couple of years experience observing variable stars improved my threshold by around 1.5 magnitudes.

#33 george golitzin

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Posted 09 October 2013 - 03:58 PM

Pete, nice post and sketches--and a very nice catch of Triton in an 8-inch. I've seen it in 10 inches, but never tried 8--I'm kind of lazy that way :crazy:.

-geo

#34 SabiaJD

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Posted 10 October 2013 - 08:45 AM

Ralph,

A good read of your observations of the moons Oberon and Titania with the C-14.

Had my first chance to look for these moon with a RC20 f/8.1 on October 2, 2013 at 11:15 EDT. Low humidity and dark sky conditions.

With a 12mm (342x) the moon were just visible, very evident with the increase of magnification to 424x and then 857x.

Uranus showed a pale white center with greenish outer rim around the edges. Not expecting to see any surface on that distant planet.

The moons were at 2 and 8 position with respect of the planet Uranus. Identified them later with software Guide V8. Four of my friends were observing that night with their scopes had a chance to see these moons. Titania proved a be the more difficult to see for them. Both of the moons were around 28 arc seconds from the center of the planet on opposite sides according to the software Guide 8.

About 20 minutes later we viewed Neptune at the same magnifications and found Triton a much easier target 15 arc seconds in the 9 o'clock position from Neptune. It's position also verified later with Guide 8.

A thin veil of clouds prevented see these moons again on October 8, 2013.
Will try to show these to some of the college students taking the astronomy course at the next chance. They usually get to view these planets at low magnification.

John D Sabia

#35 yesplease

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Posted 10 October 2013 - 02:08 PM

I'm almost positive I saw Titania Mag(13.5) on Friday and last night with my 5 inch apo. The conditions were perfect, though. I'm going to keep looking and see if I cant see it on the other side again. Both Oberon and Titania should be on the other side on the 11-12 of oct. Last night Jupiter was crystal clear at 317x, just to give an idea of how good the conditions were here.

Good info
http://www.universet...013-opposition/

#36 Astrodj

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Posted 11 October 2013 - 12:17 AM

Pete,
I think your color rendition of Neptune and Uranus is very much what I see. I don't have the experience of some in this thread with these planets, I usually observe them close to opposition and that's about it. But, I have been observing them since the mid 70's with 10" aperture and your drawings are captivatingly close to what I see.

Concerning color perception, I'm curious what you, or David Grey think of this online color test. I found it to be quite challenging, and after taking it I have a better idea of which colors are easier for me to distinguish subtle differences between and which are more difficult. Are tests like this informative, or bogus do you think?

#37 David Gray

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Posted 11 October 2013 - 06:19 AM

"David Grey" - Who He :question:

Scored 17/99 (0 perfect): perhaps work on your greys :grin:

Have to wonder about monitor fidelity tho' and Internet similarly.

Regards,
David (Gray).

#38 azure1961p

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Posted 11 October 2013 - 09:00 AM

The test - lol - it annoyed me and I never completed it. All these nauseating shades of yuck. When I did try it again it was on my iphone and it didn't respond to my touch screen so I left it there.

Dave GrAy makes a good point (I too used the E come to think of it) - my iPhone is different than my laptop or pad - infact all three are slightly different. I think the absolute worst color shifts was back in the days of the fat bulky CRT screens - there was a whole host of issues there and when the even started to smell old age the colors and contrast bellied up. A new one wasn't bad but they varied still and again died early.

I'm glad you like the renderings I did - I know if I observed from a dark site that Neptune would have more teal though Im uncertain if Uranus would have changed. I would like to once and for all get 9/10 seeing or better with these two but with winter on its way the jetstream is starting to sag back down over here and that makes these two particularly vulnerable to its softening effects. Well last year at least I had 7/10 right up to the last week of November so I could luck out but it gets slim as the weeks pass.

Glad you liked my work.

Pete

#39 Astrodj

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Posted 11 October 2013 - 01:15 PM

"David Grey" - Who He :question:

Scored 17/99 (0 perfect): perhaps work on your greys :grin:

Have to wonder about monitor fidelity tho' and Internet similarly.

Regards,
David (Gray).


David Gray,

Please pardon my gaff, I claim exhaustion as an excuse. I'm usually very cognizant of such matters so you got me this time. :o

Not bragging or anything since I too wonder about monitor/screen differences, but I had a perfect score on the test (one of the reasons I wondered!). It did try my patience though. I had the most difficulty with subtle shades of the magenta/heliotrope color. I was surprised when I scored perfect as I was pretty certain I had botched some of those.

Thanks for weighing in, I value your input greatly on observing subtle planetary detail and have learned a lot from your many posts in the past.

#40 Astrodj

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Posted 11 October 2013 - 01:42 PM

Pete,

LOL, I almost quit the test a couple of times myself as it seemed monotonous.

I have always been able to "see" very well, but I have zero talent when it comes to drawing or sketching so I admire the talented drawings I see on this forum and yours are always great. I really do appreciate what you and others achieve with various media. It is the next best thing to being able to do it myself. ;)

I need to observe Uranus and Neptune more often. I had a very good night with Neptune last year at opposition. I was testing out a new EQ platform with magnifications of up to 600x. Once I fine tuned it a bit I settled in and observed it for a few hours at 300x and below as that was where the seeing dictated I should be. I thoroughly enjoyed myself that night. I did not discern any detail or limb darkening, nor did I glimpse anything I thought might be Triton, so I still have goals to achieve. I distinctly recall it's coloration as grey (spelling intended :grin:), with a dark, pastel blue undertone. I can still see it clearly in my minds eye. Your drawing catches the color I saw perfectly (red zone/10" dob).

#41 David Gray

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Posted 11 October 2013 - 02:03 PM

Thanks Asrodj,

Yes Pete saw your ‘E-type’ and let it go then it seemed to escalate after that…………..!! It rates a close second on my irritation-scale to being called a stargazer – sorry :grin:! Perhaps we should have thought more when we called our sons Stuart & Alan (double-whammy) – and Alan in naming his, now 6 yr. old, son Korey Ayeden……… (several whammies)!

The Test: did it again and tried to put myself in observing-mode and got 3. Then I booted up my (old) workhorse PC – the one finely calibrated for my colour work. Also in a darkened room (mood-light on and some Mozart); and again in observing-mode got it down to zero first try. The newer PC has dumbed-down display setting facilities and I like it not.

The test I feel has limited application at the eyepiece: can’t slide the hues against each other there! But more in common with how I tweak colour-adjustable vectors against each other for relative hues/contrasts etc. – in connection with tinting my drawings.

At first I really could not get enthused trying this test; but now I find it a little therapeutic/compelling! Perhaps it should have a time limit option.

Doing family tree research yrs. back WWI records showed 1023 Grays killed and less than 60 Greys – not sure what that is telling me……………!

Even the spell-checker is taking issue with the ”a” – BAH!

Pardon the digressions.

All good wishes,
David.

#42 azure1961p

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Posted 11 October 2013 - 04:37 PM

Yes the red zone (I'm in orangey-red) does mute the colors I find. It doesn't seem like that ought to be the case but there is no doubt whatsoever in my mind that I see more color in yellow and certainly green zones. The light pollution tends to mute the finer hues . I don't see this happening in other Jupiter, Mars or Saturn but clearly with the two outter gas giants.

Glad you got the 100% on the test. Next time in at a mouse ill finally go all the way with it - disgust and all.

Also glad-

You had a terrific time with your platform. I made one myself. Once I get the drive rods machined it'll go for a spin. Even if I goofed the radi or something and I ended up with a twenty minute track time - I'd be ESTATIC. I like a lot of medium to high power work when conditions permit and it'd be such a relief to finally not need to nudge. Of my three scopes only my C6 is driven. The 70mm can eek by as mags are usually low anyway but the 8" needs a drive already.

I'm pleased you found satusfaction here!


Pete

#43 azure1961p

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Posted 21 October 2013 - 12:38 AM

I saw Uranus for the first time using my C6. Seeing was 6-7/10 and transparency was moderate with intermittent slight haze. Best view was at 320x . I think for both my 8" and the C6 - you really want to be in the 300's to get a fair sense of surface area through scale. Color surprisingly was made out - a certain grey grey blue. It looked identical to the 8" views Ive had in the past though slightly dimmer as though a light neutral density filter was in use. Very pleasing view. Clearly non stellar at 61x. High power view was definately akin to a super high surface brightness planetary nebula. However the planet was bright enough in the 6" at this high magnification to show glare off the planets limb.

Very pleasing. Nice to track with the Celestron after nudging so much with my dob in the past.

Pete

#44 Asbytec

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Posted 21 October 2013 - 04:58 AM

Man, I was gonna look for Uranus last night, Pete, but the moon made star hopping pretty tough. I usually start with the circlet in Pisces and work back. That was very tough since NELM was about 4. Good on ya for doing it.

#45 E_Look

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Posted 21 October 2013 - 10:44 AM

Aw, after trying to locate Neptune unsuccessfully with the Moon out last night, I gave up also on Uranus, given the time I spent trying to find Neptune. (I went to Jupiter a little later.)

I have found that for Neptune and Uranus, on nights when the Moon is more than a crescent, forget about it!

#46 azure1961p

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Posted 21 October 2013 - 11:24 AM

Star hopping is what I do with the 8" and it can make things dicey. If there's haze the 8x50 finder with a full moon can truly be patience wearing. I've given UO more than once due to that kind of interference.

Its interesting though guys between these two scopes 300x and above is the optimum magnification . That said I believe even a 4.5" Tak apo (which according to Carlino shows more contrast than the C6) is not going to produce as good an image as the Celestron . These outter gas giants put conditions on observing that leaves small aperture high performance apo in the lurch - comparatively . In truth I can't say with certainty- I haven't done an A- B comparo with an apo on these . Still it'd seem 6" aperture is really a minimum where enough scale and brightness is comfortably achievable without feeling starved out.

Ed - I'm looking forward to your finally getting tremendous Neptune views again!!

Pete

#47 Ant78

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Posted 21 October 2013 - 12:52 PM

I observed Uranus for the first time last night through my small scope, yellowish green with a slight limb shading.
My original plan was to locate Neptune but after a while I gave up and looked for Uranus, used Diphda as a guide star and worked north from there, the Ram constellation stars Hamal and Sheratan also helped point me to Uranus. Could not resolve any moons as they are beyond my scopes limiting magnitude but reading everyone's reports of its moons is great reading.

#48 azure1961p

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Posted 22 October 2013 - 12:20 AM

Another nice view of first Neptune then Uranus. Uranus appeared sharper and with better limb definition owing to its greater altitude in the sky. I wasn't sure completely that I had Neptune at 61x but the queer color gave it away and 226x confirmed it was the right *star*. Both were best at around 216 x due to seeing. Uranus was a far sharper orb however and tended to just lay there with it the fuzzings Neptune had.
Some of the best views so far of these with the C6.

No moons though however Triton had a field star masquerading as Triton.

Pete

#49 E_Look

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Posted 22 October 2013 - 11:18 PM

... No moons though however Triton had a field star masquerading as Triton.

Pete


Yeah, LOL... bin dere dun dat!

#50 oleg oleg

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Posted 25 October 2013 - 12:46 PM

Gentlemen, please explain reasonably, why is it that photographers can not get a good picture of Uranus (and Neptune) in the visible range?    On other planets (Mars, Jupiter, Saturn), they have achieved impressive results.  This raises the question, not fiction if those belts and clouds, which observers say?






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