Zermelo

And possibly one of the better ones, if it's clear: https://bigthink.com/starts-with-a-bang/2023-geminids-best-all-time/

That's awesome - if you spend enough with them, they throw in a surface-to-air missile! Or is that only for american customers?

You will never tire of the view of those two, together in the same field.

Yes, a glass, by definition, has a disordered composition, unlike a crystal.

https://stargazerslounge.com/topic/362613-sky-watcher-az-gti-tracking-noises

From a purely linguistic point of view, fluorite of any sort is crystalline calcium fluoride. "Synthetic" means it has been grown in a lab/factory, "natural" means it was dug up, but I would say both of those qualify as "real". Any commercial telescope objective is too large to be made from natural fluorite (which often has impurities anyway). FPL-53 should presumably be described something like "variety of glass having optical properties as close to fluorite as makes no difference", but that might be too long to fit around the outside of the objective.

Prepare yourself for a midnight visit from the JNES (Jovian Nomenclature Enforcement Squad).

I use a 6" Newtonian on a conventional tripod+alt-az mount. The reason that Dobs tend to dominate on larger sizes is cost. To mount a 10" Newtonian on a tripod alt-az as steadily as a on a Dob base would cost a lot more. With a Dob, you are maximising the aperture you can get for your outlay.

I paid even less when I bought mine. The prices on some of the Svbony kit do fluctuate massively, both locally and from China. It's worth keeping an eye out if there's something you're after.

Synscan Pro v2.4.10 (Android) This version has a couple of bugs, noted here. At the time of writing, this version has yet to be added to the change history. That list mentions four intermediate versions since 2.3.7, for which I did not see updates in the Google Play Store. Among other changes, the history mentions changes to the way that further stars are used to improve goto accuracy.

You have had some good suggestions above, but £30ish will seriously restrict your choice. If you don't mind ordering from abroad, there are a couple of other options. If you can stretch to £37, you could replace your 10mm stock eyepiece with one of these: https://www.aliexpress.com/item/1005006018468922.html It has a 60 degree field of view (like the Starguiders) and gives a good, sharp image with minimal distortions. As has been mentioned already, it would only give x65 in your scope, so you would still need a Barlow lens to give decent views on the planets. Or, for around £28, you could get this zoom: https://www.aliexpress.com/item/1005005756520671.html (there are three different models under the one listing - I'm talking about the 7-21mm version) A zoom gives you a whole range of magnifications in one unit, and is very handy if you're on a budget. I've not used this particular one, but it has had some good reviews. This would give you a decent magnification range of around x31 to x93, but for planets you would still want to combine it with a Barlow on good evenings, where you can use higher magnification.

When I did my review, the only other zoom I had to compare it with was an OVL Hyperflex 7.2-21.5mm, and the Svbony action was noticeably easier than the OVL. I did note that the final 4mm-3mm adjustment was less smooth, probably because that change involves the most movement of the eye lens on the stalk. And I, like the CN reviewer, have gotten used to tightening the focuser screw a little more than I would for a fixed EP (but not more than for the OVL). My subsequent acquisition of a Clicklock took care of that. More recently, I bought a Svbony 9-27mm, and the action on that is easier than on either of the other zooms. I think I've had the 3-8mm long enough now that it's not going to change, and I do get the feeling that the resistance is caused by the mechanics (velocity ratio?) inherent in the design, rather than friction or thick lubrication.

It's here: https://www.cloudynights.com/topic/862337-2023-eyepiece-buyers-guide/

Well, it gets better https://www.space.com/nasa-lucy-asteroid-dinky-3-space-rocks-contact-binary

I've found them to be responsive to feedback in the past.

That's an interesting contrast to another live thread, where the consensus seemed to be that smaller refractors outperform larger reflectors in iffy conditions.

Oh yes, I see what you mean. When you choose a deep sky object and hit goto, it counts down to zero but it never gives you the screen to confirm. I don't know how this release made it through regression testing. I've not used it in anger yet, I'm just trying this out on emulator mode. I haven't done any observing since I upgraded, and in any case I use sky safari for most things during sessions.

Yes, this is true, though the crucial difference is that you have identified your target before pointing. The mount can then use your location and local time to work out where in the sky the object ought to appear, and use that to orient itself and calculate the tracking parameters. My interpretation of the OP question was just a point at a target without identifying it (or perhaps even knowing its identity).

I've just tested SynScan Pro 2.4.10 on my Android 11 phone, and I too get the bright screen during goto. Clearly a bug. Pro 2.3.7 under Android 13 on my tablet maintains a red screen during goto.

(1) I've had an issue running Sky Safari on my Android tablet ever since it updated to V13. It gives an error whenever it waits a long time to respond, and from then on it repeats in a loop until you kill it. Several others have reported the same thing, and devs have been working on it for weeks. (2) I do sometimes get a glitch where, on first attempting to connect from Sky Safari after alignment, the star chart points to a "home" position (on the horizon) rather than the actual scope direction as known to Synscan. This is very easy to deal with, though - if I disconnect and reconnect in Sky Safari, it always picks up the correct position on the second attempt. (3) On Synscan, I've never had the screen brightening last for the duration of a goto, but I do see a brief flash of light when I switch apps. This is a problem at the Android level, apparently iOS gives you the option of a system-wide red screen. Which version of Sysncan are you running? As you say, it sounds like a bug in the latest update.

This is generating some interesting discussion. In the end, I doubt that any definition can be made that negates all of the objections. "planet" is a very ancient concept that has been tested by modern discoveries, and found wanting in some respects. But I suspect that the professionals might have fewer problems with the terminology than some lay people. After all, astrophysicists quite happily refer to oxygen a metal, so I'm sure planetary scientists have no hang-ups about whether an object is described as a planet, dwarf planet, asteroid, satellite, or something else. The important thing is whether it is interesting enough to warrant study. As has been mentioned already, there are many smaller objects that have been found, unexpectedly, to be geologically active, to sport exotic lakes or glaciers, to possess subsurface oceans, to be shrouded in strange atmospheres and more. A prime example is the lately-demoted Pluto itself, once assumed to be a boring chunk of icy rock, and now known to be one of the more interesting places in the solar system.

Apparently 2007OR10 goes by the name of "Gonggong", which I had thought to be a giant panda loaned by China to Huish Episcopi Zoo.

With a Dob (Newtonian), you already have the secondary mirror and spider vanes obstructing the light, but you don't see them (if the image is in focus). What you do get is some diffraction at the edges of the obstruction, which reduces image contrast. A focuser extending into the tube will have the same effect. I have a similar situation with my Newt. What I was concerned about was the draw tube being a very shiny silver on the outside, which I thought might give some unwanted reflections.

Yes. If you think about it, in order to track an object, the mount needs to calculate (instantaneous values for) the direction of motion of that object, and its speed. This will vary with both the object's altitude and azimuth. Extreme examples might be an object on the Eastern horizon, rising, and one in the West, falling. The best way to allow the mount to do that is with trial alignments on other known objects, which allow it to orient itself against the sky. The alternative point-and-track method relies on you first levelling the mount (so that it can then use your subsequent elevation as the altitude of the object to be tracked) and pointing it North (so that it can use your slewing about the vertical as its azimuth). It then "knows" which part of the sky it is pointing at, and can use differential equations to calculate the speed and direction for tracking, but the accuracy of the results will depend on the accuracy of your previous alignment.

The nearest couple of doubles in the Cambridge Double Star Atlas are STF 797 and STF 816, both with a main component around +7 and companion dimmer than +9.