Zermelo

Hello, I'm not sure what "authentic" would mean for the Messier list. I don't believe that it is managed by any official group like the IAU, unlike the names of stars and planets, or the boundaries of constellations. Messier himself released two versions of the list, and then a few more objects were later added by other astronomers who believed that Messier (or his collaborators) had observed them, but had not included them in the original list. The status of M102 is still the subject of some debate. The best starting point is possibly Wikipedia, which has some links to further resources.

It may be clear later on, but I decided not to stay up late tonight. Instead, I set up the binoviewer with the Mak on the AZ-GTiX for the first time, and spent a pleasant half hour on the moon at lower magnifications. Gassendi is showing nicely on the terminator, the rim and central peaks picked out. Further north, the Jura Mountains are also looking good, and Herschel and its companions are just making an appearance.

That's terrible. And you can see those tell-tale parallel tracks, in formation - probably SpaceX again.

The moon in Leo is getting more dominant now, so this evening I stuck to doubles over on the other side of the sky - in Serpens, Ophiuchus, Hercules - 15 of them. The seeing was reasonable to good, transparency decent, and no appearance of the low cloud that was forecast. The best was probably HD 133408 in Virgo, wide at 10.1" and both components below +7, but with a subtle orangey-blue contrast.

A double first for me tonight, using the Mak 127. After reading recent discussion about 3C 273, I decided to give it a shot. It wasn't difficult matching the nearby star patterns with Sky Safari, including Zaniah, and from there to find HD 108959. There was a very faint (visible with averted vision) "star" in approximately the right place and, after about twenty minutes of checking, I convinced myself that it was indeed the quasar - my first. 2 billion light years, apparently. I also made a successful attempt at the supernova in M101, again my first one. This also took quite a long time to confirm, but actually was readily visible, even with direct vision (M101 itself was a barely perceptible smudge). I see that others are saying it's about +11 at the moment. This one is a mere 23 million light years away. Well done, little Mak.

Congratulations Arnaud, and great publicity for the hobby. (first time I've ever watched the One Show)

I'm agnostic about piers.

Hello, If it's a long way off, it's often caused by the location or date/time being wrong. How are you setting those with the Adventurer?

I had this one as a boy, along with "Exploring Space" and "How it Works: The Rocket". They were all given away at some point and bought back, in the last few years, on the Sinus Echonis. Even after all that time, I was anticipating the picture on the next page as I read through it.

A great read, Magnus, thanks for sharing. Perfect seeing under 21.95 skies, "wow" indeed. There are some great doubles about at the moment. An interesting comparison of the diagonals - I have the Revelation too, but I've read how good the BBHS is, and thought about getting one.

https://xkcd.com/2776

Another decent night here. Seeing started average but improved during the evening, and transparency generally good, with the occasional wisp of high cloud. A few doubles in the Mak, including HR 3701 at 1.0", and then some galaxies: M65, M66 (no hamburger again), M99, M100 (barely), and four in Markarian's Chain. Finished with M13, which was showing a lot of structure in the Morpheus 9mm.

Relating this to a different thread, I've found that one of the uses of Facebook is that people in our village (and, I'm sure, many others) use it to post pictures of parcels sitting outside front doors. The parcels were ordered by the posters, but the front doors are not theirs! The delivery company (and here, it's not RM) has of course sent them the picture as "proof" of successful delivery. The message attached to the post is usually "does anyone recognize this front door?" To be fair, RM in my area is usually good.

Or alternatively, if you launch a "New Private Window" in FF, it will have no connection (including cookies and passwords) with your main session, i.e. a blank slate for each website. It's a useful option if you only need a one-off session.

I'm not aware of anyone on here who has both, but I have the Star Discovery and, quite recently, the AZ-GTiX. I've not dabbled with the innards of either mount yet, though there are threads where these have been discussed, for the Star Discovery: https://stargazerslounge.com/topic/285612-star-discovery-clutch-adjustment https://stargazerslounge.com/topic/323361-skywatcher-star-discovery-azimuth-slop and you may already be aware of the long thread dedicated to the AZ-GTi: https://stargazerslounge.com/topic/387014-skywatcher-az-gti-mount-owners-thread Yes, the nominal capacity for both mounts is 5kg, though the usual caveats apply: that performance will degrade gradually with increasing payload, that it depends on the length of the OTA as well as the weight, and that it depends whether you're using it for visual or imaging. I regularly pushed the limit on my Star Discovery, though not as far as 6.5kg. The mount has never given up on me, but it's hard to tell if the weight is having any effect. I've had some excellent sessions, in terms of goto and tracking accuracy, but it has also been quite inconsistent. I've never been sure whether that's down to inherent mechanics, or to my pushing the limits, or to the Synscan software and the mount's motor board firmware (hence my attempts to monitor the performance). I'm hoping to get a comparison with the AZ-GTiX, which uses the same control software, but different firmware and a slightly greater capacity. Yes, the Star Discovery is marketed as the Orion Star Seeker IV in the U.S., and it does seem that the payload limit is sometimes quoted differently in different markets. To be honest, I've always thought that the single-arm mounts look a bit awkward, and the ability of the AZ-GTiX (and the AZ-GTi, with the counterweight mod) to balance the load seems preferable. This site is an interesting account of one person's experiences of the Star Discovery with different OTAs, and in particular their deliberate attempts to run it beyond the nominal capacity. Apart from any variation in mechanics or software I think one of the main differences is the size of their user communities. I doubt that any official sales figures are available, but I get the impression that the AZ-GTi has a substantially larger user base, in part because of its ability also to do equatorial, and hence better support imaging. As a consequence, (i) the availability of crowd-sourced support is better (e.g. the SGL thread referenced above), and (ii) the support from third parties is likely to be better - for example, ADM do a saddle replacement for the AZ-GTi, but not for the Star Discovery (the last time I asked). See, for example, https://www.cloudynights.com/topic/661513-skywatcher-az-gti-useful-links-and-accessories .

The seeing here was better than on Thursday, and I split a dozen doubles with the Mak. Izar and Algieba were looking good. The tightest tonight was HR 3701 at 1.0" with a magnitude difference. M5 and M13 were showing well, and the planetary NGC 6210 in Hercules was blueish. I don't think the transparency was quite as good as Thursday, there seemed to be a little mist about. So galaxies were not at their best, for example M65 and M66 were visible, but I couldn't see the hamburger. By the time I packed up at 01:00, there was also some dew forming, which wasn't expected. But a good evening.

Another thread over on CN: https://www.cloudynights.com/topic/441767-good-objects-for-observing-with-the-h-beta-filter/

Yes, the omens are good in the South West. CO, Meteoblue, Metcheck, BBC, Nightshift and GoodToStargaze are all predicting some clear skies. The moon is out of the way, and the seeing is forecast to be good. Dew shouldn't be a problem, and it won't get too cold. And it's not even a school night.

Impressive - I don't have an Erdinger glass, the one in my picture gets called on for any wheat beer. I need a larger glasses cabinet, but then I'd just get more glasses. Sounds a bit like my eyepiece case.

The BBC says clear tonight, everyone else says no. We know where that's going. So the Mak isn't cooling tonight, these are instead.

But now is precisely the time you don't need to apologize: https://www.theguardian.com/environment/2023/apr/28/no-mow-may-uk-gardeners-urged-to-let-wildflowers-and-grass-grow

Going back over this thread, I just noticed this After having read all this Do you have any thoughts on this week's lottery numbers?

Well it was worth sticking with it. The early cloud went away eventually and it turned into a decent evening (morning??). The seeing was mediocre, improving slightly after midnight, but it was darker than I've measured here before (21.02). Doubles included 20 Dra, HD 75353, HR3686, HD136176, and three with only a 0.9" separation: HR5550, HD124757 and HD148734. These required extended viewing to catch an occasional split. Also visited M57, M92, M53 and M64. Mid-level cloud moved in again about 01:00, much as forecast.

Yes, I just about got aligned and now that cloud bank has come in from the East and covered most of the sky. Instead, I've been watching our local hedgehog eating the treats we left out, joined briefly by a bemused neighbour's cat.