31 replies to this topic

[aatdalton]

Last night around 2:30 while checking out various DSOs while my imaging rig was running, I happened to notice that both Uranus and Neptune were in pretty decent placement to view as I was swiping around Stellarium on my phone. I did a pretty long star hop starting in Pegasus and ending up at Neptune, just outside Aquarius. 

 

Wow! While still very small in my 8" dob with ES82 11mm, the color of Neptune was incredible. Brilliant deep blue. Much richer color than any blue stars I've seen. I could faintly make out the disc of the planet, and could confidently say it was not just a point source of light. My skies had a little bit of high level haze, so I didn't try for a high magnification. 

 

Next I turned east to track down Uranus. After another star hop, I had it clearly in my eyepiece. Wow again! This one had a much more distinct disc to it, clearly not a star. The other dead giveaway was the pale green hue. Reminded me of some planetary nebulae. Absolutely beautiful staring deeply at Uranus. I'm fairly certain I could pick up Ariel as well. I'm sure I could have seen other moons if I had realized where they were and tried identifying. 

 

I think it's so amazing that with fairly amateur gear, I can directly observe these incredibly distant planets from my backyard. And of course my wife and I had some fun laughs about me looking at Uranus last night. 

 

Clear skies all!

[Migwan]

Love that blue.  Never thought of moons with either of those.  Sounds like you had a good night. jd

[Cali]

Have you been able to check out Titan?

 

- Cal

[Redbetter]

I have typically found Triton to be fairly easy to see with the 8" SCT looking at Neptune in rural sky.  However, I haven't tried for it in recent years in the much brighter suburban backyard with its incredibly poor seeing.  I did try for it once a year or two ago with the 110 refractor at a low elevation rural site, but the seeing was poor  (even for ~4" scope), effectively obliterating dim objects next to "bright" ones.  I have been wanting to try that again with the refractor at a site with better seeing, but I don't typically haul it to the dark site when the 20" goes...just too much extra time in setting up/taking down a refractor this size when I already have the big scope in action.

 

I doubt you saw Ariel with the 8", especially at only ~110x and with haze.   Not sure of the time zone, but there was an 11th mag star NNW of the planet, somewhat outbound from Ariel last night.  If you saw only one moon candidate and it was not that star, then Titania is the most likely.  For perspective, in dark, transparent, and steady skies I could typically catch Titania with the 8" SCT (barely, but with certainty each time) and rarely Oberon. This was in the 225 to 300x range.  Never succeeded on Ariel or Umbriel with that scope that I can recall.  With the 20" in dark sky I can catch the dimmer two with sufficient power if the seeing is not too poor, but that is typically 500x or more to get some separation.  I have seen the set of four easily with a 17" in good seeing and dark sky.  For these inner moons seeing is a major player.

[aatdalton]

Yeah, it appeared up and to the left in my eyepiece so southwest in the sky I guess. Probably that other star but it was definitely tucked in tight. Would definitely like to come back and look harder for moons.

[ww321q]

I watched Neptune early Saturday morning. My 6" reflector showed a pretty clear disk but the color wasn't is good as you had. I've been able to find it pretty easy using  my widest true fov eyepiece.I use this site to help me know where planets are. I'm hopefully going to get up early tomorrow and try for Uranus. https://www.timeandd...ght/usa/atwater

[Zorbathegeek]

I'm looking forward to finding Neptune when the moon is less bright. It will be 40% alt' by 11pm next week from my latitude. I star hopped to find (16) Psyche, (15) Eunomia and (39) Laetitia last week - until my brain melted down! So Neptune should be fairly easy. I only have a 6" Dob' but find the field of view great for tracking asteroids. (135) Hertha and (21) Lutetia next month! Gonna have to wait a while for Uranus. I always have good intentions that I can get up at 4.30am but generally flag it when the hour arrives. 

[Richard Whalen]

I observed Neptune last night in my 5" f15 refractor. Best view was at 500x, small blue round disk. Very sharp view. Neptune is well placed and easy to find right now.

[Pcbessa]

I spotted Uranus and Neptune with my new 10" for the first time these last days. Whilst I clearly spotted the beautiful sharp disks of both - especially between 250x and 500x - I failed to detect any moons. Uranus has a very strong glare (as it is very bright), that makes it difficult to spot the Titania. In Neptune, Triton is very near the planet, and it is also faint, and I couldn't spot it. But it seems it would have been easier than seeing Titania. I patiently looked out for the moons in both planets for 20min. I will wait for the opposition.

Edited by Pcbessa, 01 September 2019 - 04:58 PM.

[tchandler]

Congratulations on your discoveries! I take it that these were your first observations of the outer planets?

 

Uranus is a beautiful pale teal in my 152/1200 refractor. Definitely a disk, even at 100X. Have yet to see any of the moons. 

 

Neptune is conveniently located near the 4th magnitude star phi Aquarii. Last week I observed Neptune with a friend’s 24” f/3.7 Newtonian. Pale blue - almost grey - with barely a hint of green. Seeing not great but a disk was observed at 200x and up. At 300x and up Triton popped into view. Several others took a look as well and I was surprised that a few were unable to see the moon about 12 seconds from the planet.

[Redbetter]

Seeing has a great deal to do with recognition of dim moons near planets that are many magnitudes brighter.  Crappy seeing operates as a glare magnifier, perhaps a second order effect.  First order is the increased glare, and second order because of the increasingly diffuse nature of the dim component do to seeing spreading its light over a far larger area as well. Both of these are contrast losses.   [The caveat is that contrast impact on visibility is often more of a half mag response per magnitude background change due to sky brightening/contrast...so the net might be closer to adding two 0.5 order effects to get first order.]    Add to that poor seeing often involves rapid and large focus shift,  and makes it harder for the eye to track such changes--younger eyes might handle this much better.

 

And some folks have more difficulty seeing a faint object next to a bright one.  For whatever reason their visual acuity for dim targets next to bright ones seems to have a smaller dynamic range.  That is applied to side-by-side comparison.  You really can't compare vastly different seeing and sky darkness for different observers.

[tchandler]

Thanks Redbetter,

 

I appreciate your concise explanation. Additionally, observer experience contributes as well, including how/where to orient the eye at the eyepiece, further confounded by the relatively rapid apparent motion of objects in the FOV at high magnifications. It’s like shooting a fruit fly while jumping from a moving train! Anyone who successfully observes these challenging objects should know that they deserve a small round of applause!

Edited by tchandler, 02 September 2019 - 08:01 AM.

[RocketScientist]

What do other observers here in New England find to be the minimum aperture and power to reliably see Triton, Titania, and Oberon? (Ignore the inner moons for now.) It is very rare that I find it worth running much more than 200X in central Vermont. We get good transparency occasionally, but good seeing is very rare. This makes it difficult to see detail on planets.

 

I looked for Neptune in the ETX-80 a few days ago at low power, so no disk to give confirmation that I found it, but I saw a point object whose color could only be described as insanely blue, very different from the typical blue-white star. Maybe it was Neptune, maybe not. Clouds were passing over and a first quarter moon was out, so it wasn't worth bringing out a larger scope.

 

When the current snowstorm passes, I'm planning to pull out the ETX-125 and the Z10 and take a much closer look at this planet and hopefully spot Triton. I'll look for the Uranian moons once our Moon moves on past. 

 

--Cathy

Edited by RocketScientist, 11 November 2019 - 03:12 PM.

[RocketScientist]

Endless clouds and snow...

 

But I was able to see Neptune with the ETX-125, and I'm now pretty confident that I also saw it in the ETX-80. The position matched that where electronic charts showed it should be.

[Sheol]

          I remember my first view of Uranus, some years ago. What surprised me most was the color of the disc in my 8 inch 8XTi. It really does resemble the color of some of the planetary nebulae. At least the bluer ones, to me. That was a thrill, I didn't think I could actually do that star hop but it worked! I have not tried for Neptune, maybe when the new scope arrives, I will give it a shot.

 

 

         Clear Skies,

              Matt.

[KBHornblower]

Last night around 2:30 while checking out various DSOs while my imaging rig was running, I happened to notice that both Uranus and Neptune were in pretty decent placement to view as I was swiping around Stellarium on my phone. I did a pretty long star hop starting in Pegasus and ending up at Neptune, just outside Aquarius. 

 

Wow! While still very small in my 8" dob with ES82 11mm, the color of Neptune was incredible. Brilliant deep blue. Much richer color than any blue stars I've seen. I could faintly make out the disc of the planet, and could confidently say it was not just a point source of light. My skies had a little bit of high level haze, so I didn't try for a high magnification. 

 

Next I turned east to track down Uranus. After another star hop, I had it clearly in my eyepiece. Wow again! This one had a much more distinct disc to it, clearly not a star. The other dead giveaway was the pale green hue. Reminded me of some planetary nebulae. Absolutely beautiful staring deeply at Uranus. I'm fairly certain I could pick up Ariel as well. I'm sure I could have seen other moons if I had realized where they were and tried identifying. 

 

I think it's so amazing that with fairly amateur gear, I can directly observe these incredibly distant planets from my backyard. And of course my wife and I had some fun laughs about me looking at Uranus last night. 

 

Clear skies all!

Your color vision at Neptune's brightness is better than mine.  I can see the blue under good conditions, but for me it is subdued.  You appear to be a very capable observer with good equipment.

[Sheol]

       I'd probably have to echo that. I'm guessing my view of Neptune would be Grey-blue more than blue. I've lost some color perception as I have aged. Lots of things that used to look very green or blue to me now are much more subtle. I need a filter on M.42 to see much greenish-blue which I used to see even with 70mm refractors. Now its grey with a bit of blue or green.

 

 

    Clear Skies,

       Matt.

[GeneT]

I enjoy viewing Uranus and Neptune. They aren't as spectacular as Jupiter or Saturn or Mars. However, I am impressed that I am looking at the furthest planetary objects, minus of course, Pluto. Ever seen Pluto? 

Edited by GeneT, 05 November 2020 - 07:15 PM.

[Sheol]

            It looks like just another field star. You would have to have very very precise star charts & deep as well, to locate Pluto. And a great deal of patience, if you were going to try visually detecting it. I think most would use CD images, and wait for its movement to give it away...

 

                        Clear Skies,

                            Matt.

[Redbetter]

For me Pluto is in reach of a good 4" refractor in transparent Bortle 2 skies in good seeing (I have done it several times with a 110ED in recent years.)  A key limitation is that it is still low enough in the sky for many northern observers that transparency issues, seeing, and any light domes to the south will increasingly obscure it.  Experience goes a long way toward getting the most out of a given instrument, but an 8 or 10" should be sufficient in truly dark sky.  As a novice my son found it easily with a 10" on his first try at 41 deg N in very dark sky.   

 

S&T publishes a finder chart for Pluto every year and this is pretty good.  It goes deep enough for the surrounding star field that Pluto is generally recognizable as being an extra "star" of about the right relative magnitude.  Planetarium software such as Stellarium can help if one is seeing more additional field stars than expected.  The relative magnitudes don't always match the visual impression down in the 14 to 15 mag range.  Cross checking with Wikisky can also help.  There are times when the star field appearance is now what one would expect from the chart and Pluto's expected position--usually because one star is somewhat dimmer or brighter than expected, and some additional field stars not on the chart are just visible enough and near enough to cast doubt..  Viewing on different nights will reveal the movement of Pluto (the standard for confirmation if there is any doubt.)

 

Don't forget Ceres as a dwarf planet.  Ceres can reach barely detectable naked eye visibility (for those that can detect ~7.0 mag NELM) during favorable oppositions.   With enough aperture and steady enough skies its disk becomes semi-resolvable at about 0.7+ arc seconds, only slightly smaller than the moon Europa presently is as Jupiter is shrinking while we pull away from it.   

 

Then there are the dwarf planets that provide a major challenge:  Makemake and Haumea.  These are in the 17+ mag range and require some careful plotting and steady dark skies to pick up visually even in the 20".  Those have required some effort with wiki sky images, sketching/marking what is seen and looking for movement over at least two sessions.  Eris is beyond the reach of my 20", in the 18.7 mag range. 

[Sheol]

         But they do not show large discs in your scope. Nor will Pluto, they will just be very small specks of light. You will need S & T's charts to find them, that is for sure! But I also do get that the real thrill is in the chase.  

 

      Clear Skies,

        Matt.

Edited by Sheol, 08 November 2020 - 07:23 PM.

[Sheol]

         You know, I have never thought of trying for Ceres. Has anyone here tried that minor planet? I would actually be quite excited if I caught a glimpse of Ceres. What about any of you? 

 

        Clear Skies,

             Matt.

[Redbetter]

         You know, I have never thought of trying for Ceres. Has anyone here tried that minor planet? I would actually be quite excited if I caught a glimpse of Ceres. What about any of you? 

Like I said, it isn't hard to find.  I have seen it naked eye under very dark sky.  With the 20" during close approach Ceres resolves to a disk to some extent even in mediocre seeing.  When compared to a 7th mag star in large aperture the star has somewhat of a first ring/diffraction pattern while Ceres does not, and the latter looks somewhat larger.  The image is steadier for the dwarf planet than for a star. 

[Sheol]

        I don't think it would have much of a wow factor for me in an 8 inch, visually anyway. Knowing I had found it though would be rewarding enough. I am thinking of going hunting for Neptune soon though. Time to find Ice giant #2. 

 

        Clear Skies,

        Matt.

[Pcbessa]

Wow this thread went from first light of Uranus to spotting minor planets like Makemake!

In my 10", Uranus is seen as a small greenish ball, without features, and 2 moons that I can see with some difficulty (Oberon and Titania).

Neptune is seen as a tiny blue disk and Triton can be spotted although also not easy.

Pluto is "easily' spotted with averted vision in very dark skies, it's as easy as are the moons of Uranus.

I never tried to see Ceres. I can see the very tiny disks of Jupiter moons. Thought they are seen very small. I would love to spot details on Ganymede but with Jupiter low in the sky, that's impossible.