Zermelo

In my experience that's the usual culprit, though I think there are sometimes also utilities bundled with vendor-specific Android flavours that do a similar job.

Here: https://www.astroleague.org/double-star-observing-program/ and available in SkySafari import format: https://www.skysafariastronomy.com/repositories/skylist/Astronomical League/AL Double Star List.skylist also http://web.archive.org/web/20170419050003/http://astronomy.eaglecreekobservatory.org/doubles/ https://bestdoubles.wordpress.com/

It seems I was premature. In my most recent session, SkySafari lost connection with the scope several times. As usual, it was actually SynScan causing this and, when I checked afterwards, I found that the Android setting that I'd previously changed had been reset to default. Android tries to preserve battery life by preventing apps from continuously running in the background (it calls this "optimisation"). This is generally a good idea, but not what you want if you're using SkySafari in the foreground and relying on SynScan in the background to talk to the mount. The settings navigation and display sometimes vary with Android version and device manufacturer, but you need to get into the Android settings for the SynScan app, and find the battery settings within that. On my tablet, the options look like this: and you want it set to "unrestricted". Android should then let SynScan run in background without timing it out.

https://stargazerslounge.com/topic/401135-a-good-night-to-see-iapetus/?do=findComment&comment=4407532 ?

Not quite completely off the topic: https://www.facebook.com/groups/dullmensclub/permalink/1313987909257747/

That's brilliant, I wasn't aware of that. It even has an entry in SkySafari. It would be a good first clue for a question in round 1 of Only Connect, with clue 4 being "unicorns".

Not necessarily within the square.

You can start the apps, but yes, connect Synscan to the scope first. I start both apps at the same time because I sometimes need a reminder of where the Synscan alignment stars are, so I look them up in SkySafari. But I align in Synscan first, then connect SkySafari, and it automatically goes to the current position (i.e. the final alignment star). I find that (uncommonly) sometimes SkySafari will connect, but it thinks the scope is pointing North/level, i.e. where the alignment started. But just disconnecting and reconnecting SkySafari will cure that.

That might take the record as the most significant purchase ever made to avoid a postal charge.

Courtesy of @The60mmKid, some excellent books. Although I use planetarium software to manage sessions and and create plans, I also like to have books to browse and inspire me.

Hello, have you seen this current thread:

Vulcans are known to be stronger than the average human

I've just come in, as cloud is starting to appear. The forecasts for the last three nights were far too pessimistic (apart from the BBC) so I set up anyway. It was a really excellent evening, transparency and seeing were both very good. The milky way was obvious and detailed, withe the great rift showing well. In the Mak, a variety of targets looked excellent. Open cluster IC4756 filled the widest eyepieces with stars. The Wild Duck was also on good form, at low magnifications showing granularity more like a glob, and resolving at higher power. M92 was as good as ever, while NGC 6934 in Delphinus is one of the less impessive globs, just a faint patch. Planetary NGC 6572 was obvious, but without colour, and M27 was showing its apple core shape well. Doubles included HD 203358 and HR 7083, and iota Cassiopeiae was much better than it was last month - three components were showing very clearly, and the set was motionless and very beautiful. Saturn in a yellow filter showed the Cassini division and the barest hints of cloud banding, along with moons Titan and Rhea. Jupiter showed four bands, but went behind the encroaching cloud before I could get a decent look. It was also the first outing for my 12.5mm Morpheus, and it did not disappoint. In particular, it gave very contrasty views and a dark background. The second light for the SvBONY 9-27mm was also very successful - sharp, with decent contrast.

Yes, the problem is the additional phosphors. As soon as cheap blue LEDs became available, it was possible to create a tri-colour bulb that looked white, but the reflected light from such a source does not render many colours faithfully (ie as sunlight does). Hence the incorporation of broadband phosphors, using their continuous spectra to produce more natural colours. LED bulbs are now often described with their colour rendering index, in addition to their luminance and colour temperature. I suspect that the market for interior lighting has driven the change, but in surveys people often say that they value "natural" street lighting too. Since I bought a pocket spectrograph, I've looked at white LEDs (inside and outside) to see if I can find any pure tricolour bulbs, but every one I've tried has had a continuous spectrum.

Excellent. What sort of ages were the punters?

The 4.5mm I managed to pick up all the others second hand, but I may have to get that one new.

I already have the case 😀 The final EP will be on my Christmas list.

An amazing evening and an enthralling write-up. Thanks, Magnus.

Courtesy of @Astro_Dad , a barely-used 12.5mm: I'm now in serious danger of completing a set.

Yes, the clothes peg is a must, I'm surprised SW don't include one as standard. Cheapskates.

Now available on Sounds, with a few extra minutes at the end https://www.bbc.co.uk/sounds/play/m001qdx1?partner=uk.co.bbc&origin=share-mobile

That is true, but you won't see any difference between F/15 and F/11.8, if that's why you're asking.

Just after 9 o'clock this morning, on BBC Radio 4. Melvyn Bragg and guests will be discussing Albert Einstein.

One of the annoying features of the switchover is the lack of consistency between local authorities/their chosen contractors, and the slow emergence of best practice. Some have done their research, and sourced and fitted new units that direct the light downwards, make them no brighter than absolutely necessary, remove the blue end, and automatically switch them off at some time. If such a scheme replaces older lighting that was intrusive, then it is possible that it might constitute an improvement (though the point about filtering would still apply). Too many do not.

Without wishing to pry ... one factor you haven't mentioned is managing the weight and awkwardness of a larger scope. I currently have a 6", and I know I will want to get a larger one at some point, but I doubt it will be a 12". I could manage it now, but I'm thinking ahead a few years, when it will become more of a struggle. Obviously some makes and designs are lighter than others of the same aperture, and an important consideration is whether a specific scope is easy to assemble/disassemble, so that you can transport it in easy parts. Some manage with larger scopes because they have a handy shed and need only trundle it a few metres to the observing spot. The same scope might not be feasible if it lived upstairs in the house. And it probably won't be a binary decision - a scope might be manageable without causing hernias, yet just that little bit too much hassle for those evenings with a borederline weather forecast, so it might end up getting less use than it ought. Flocking - yes, it can increase contrast and improve visibility of fainter objects. It's difficult to be definitive, because it depends on context, such as how dark the inside of the tube was beforehand, and how much stray light from neighbours you have to contend with.