Zermelo

... but with eypieces that already have generous eye relief, adding a Barlow may test your "floating" skills, hence the telecentric. Not likely to happen on the Svbony zoom, though.

https://astronomy.stackexchange.com/questions/48397/how-are-radio-telescopes-pointed

I've observed iota Cas a few times in Bortle 4, and I've seen the yellow and blue coloration only once, faintly, with a 150mm Newt and an OVL Hyperflex zoom. On the other occasions, all three looked white.

HD 5938, HD 3396, 57 Cnc, 40 Sex, Algieba, Izar, HD 81670, Castor. Yes, doubles again. Though I did add M3, Mars and the Cat's Eye nebula. I stayed out until the moon cleared the neighbour's roof, high enough to cause mischief, but too low to see over my fence. The seeing was slightly better than last night, though I couldn't get the tightest doubles. I think the Mak needs a slight collimation. As @AstroNebulee reported from two counties down, there was a fair bit of high/mid whispy cloud at times. If it's in the East, it catches the moonlight. Mars was a small orange mush, but M3 was OK and the Cat's Eye was a nice, extended, irregular blue-green blob. The BBC says clear again tomorrow; CO says 100% cloud. We shall see.

M51 in an ST80 with a near full moon is a good bag

Some discussion here: https://www.cloudynights.com/topic/482350-vixen-gem-green-paint-code/

Out of interest, how does this work? For example, I know that the large UK supermarkets are generally in such a strong position compared with their suppliers, that they can just announce (for their own purposes) a sale on a product line, and tell the supplier to take a hit on the wholesale price. But in astro? Presumably it's Bresser making the calls on the (rather frequent) ES sales? Do they tell the retailers in advance, and reduce the wholesale price in the interim? What if the retailers already have the stock, do they get some retrospective compensation from the supplier if they participate in the sale?

Last night (I'm running a bit behind) I had the Mak 127 out again. I started with some open clusters in the southwest, before the rising moon got too annoying: M35, M37, NGC 2281, NGC 1647, NGC 1746. None were at their best, in the "hole" between twighlight and moon, but pleasant enough. And then 14 doubles in the Gemini/Cancer/Lynx area, though seeing was average at best, with the jet stream above the South West, and I think there was also some variable high mist to contend with. I finished by swapping the Mak for my old Bresser 70/700 Skylux, which has been languishing, unloved, in the study. It was not at all bad with a decent eyepiece, though the 14mm Morph did look a bit out of place. It looks like tonight will be better here, as the jet stream has moved away (if it's clear, that is - at the moment, CO is doing its usual last-minute flip between "best night ever" and "we're all doooomed").

Certainly make a date with 12 Lyncis, it's one of my favourites. Separating C from AB is easy, and AB (2.0") itself splits in decent conditions too. Lynx is actually quite good for doubles; aside from 12 Lyn, there are: 19 Lyn (14.8"), 20 Lyn (14.9"), 38 Lyn (2.6"), HR 2644 (4.3"), HR 2486 (4.5"), HR 3686 (1.9") and HR 3701 (1.0"), all accessible with a small scope. And Lynx is nice and high for us at the moment.

I also have the ES 6.7mm 82°, and the Nirvana 4mm and 16mm. The ES is sharp, though the targets can sometimes be dim in my small-aperture scopes. I find the Nirvana 16mm to be more comfortable to use, and it gives very nice, contrasty views of open clusters in particular. The arrival of the Nirvana 13mm came after I acquired a second hand Morpheus 14mm, otherwise I would certainly have bought one. I don't like the Nirvana 4mm as much as the 16mm. It can produce some very nice views in good conditions, but it seems susceptible to atmospherics in a way that I can't rationalize. If you already have the Svbony 3-8 zoom then I would stick with that - in my experience so far, it outperforms the (my?) Nirvana 4mm.

Hello, and welcome to SGL. There are some useful links for choosing a first telescope contained in this thread: https://stargazerslounge.com/topic/378404-telescope-starting This website also has a lot of useful information, but presented from a newcomers' perspective.

I love the top right version. Mrs. Z often complains that the objects I show her look nothing like their names would suggest, constellations in particular. I see a role for this tool in "making good" any discrepancy between an object's appearance and name. As well as inventing entirely new ones, of course.

At one point, I did think about trying to use the latitude and longitude in the table to map each location onto a scheme of country timezones, supplement it with a database of local daylight saving regimes, and so calculate the UTC offsets. I thought about it for all of three seconds.

It should reflect whatever you have set as the UTC offset in column P, for your selected location. For UK in BST, that should be +01:00, but I chose to save all the values as 00.00 as I didn't want to have it reflect the time of year that I posted it.

I’ve updated the spreadsheet (v1.2) to deal with UTC offsets correctly. Apologies, I’ve no idea how I didn’t spot that. The system tester has been taken out the back and shot. I took the opportunity to include a button to set the alignment date and time to the current values with one click, and defined a print area on the Print sheet to exclude the buttons. Slightly amended versions of the User Guide (1.1) and Design Notes (1.1) are also included.

UTC functionality: just a note to say that, since the change to BST, I've noticed that the local<>UTC conversion is wrong! I have fixed it, and will post an updated version imminently, but for now if you keep the UTC offset for your location as zero, and enter alignment times in UTC, it will continue to work. The possibility of a clear evening may take precedence over my updating the documentation.

Just got in after a surprisingly good three hours with the Mak 127 (surprising, because of the big bright thing). The forecasts all featured some cloud, but I didn't see any, perhaps just a little high haze. The seeing was noticeably improved on last night, though it did seem to deteriorate a little at the end. I started off on Venus, just because I've bought an ADC and wanted to try it out (it worked, though I couldn't see any detail on the disc). From then on it was doubles all the way (and 12 Lyncis for a triple). The colours in 24 Comae Berenices and 35 Sextantis held up well in the glare. HR 1669 at 1.6" was the tightest split. The Svbony 3 - 8mm zoom performed well again, only marginally surpassed by the 6.5mm and 9mm Morpheus. I did finish with the moon, though it was a bit wobbly by then. There was a nice crater on the terminator with the central peak illuminated, my atlas suggests it was Lagrange T.

First time out since March 9th, and just a short one. Conditions were mediocre, so my first attempt with the binoviewer was probably not a fair one. The moon was boiling a bit, but there was some nice detail between Mare Humorum and the terminator. Schickard looked good, half in shadow. Mars is small now, though I think I could just see some albedo detail in the Svbony zoom at x375. M36 and M38 were OK, though a bit washed out, even away from the moon. And some doubles: HR 1847, SAO 114265, and HR 1902, the best at 1.2". Hoping for more tomorrow.

I listened to this today. Perhaps unsurprisingly, the host was more interested in the standup comedy than the mathematical physics, but it was a good listen. And I'm guessing that it's the only episode that has ever discussed the Bortle scale.

This comes up fairly regularly. Apologies @bosun21, you may have already done your research on the following, but for others looking at this, three more points: (a) Lab tests have shown that significant numbers of imported lasers exceed the 1mW UK limit, even where the specs says they don't. Some are massively over. (b) Be especially careful if ordering the 532nm variety, as these use frequency doublers on IR lasers to get to the green output. The potential problem is that the efficiency of the conversion falls in cold temperatures, leaving substantial amounts of IR output. There is supposed to be a cut filter to remove it, but some don't work very well (or are missing). Your eyes can be damaged, and the blink reflex won't cut in as it's mostly IR. 520nm lasers are inherently safer as they don't use this mechanism, but most of the cheaper imports are not of this type. (c) In the UK at least, the legislation now makes shining a laser at a plane (or other vehicles) a strict liability offence, i.e. they don't need to prove that you did it deliberately to ensure a conviction. I do understand the appeal of using lasers on scopes, and I have several times thought about trying to find a "safe" one, but always decided against it.

Hello, welcome to SGL. One advantage of having the same true field of view at a higher magnification (i.e. the ES 24mm in your example) is that it reduces the effect of light pollution in the background sky, helping with the visibility of fainter, extended objects like galaxies. Were you particularly wanting the 82 degrees? There are the various "ultraflat" clones at 24mm/65° and 30mm/70° - for example the Stellalyra versions, or those by APM and Altair. These are very well corrected, even in fast scopes. The Superviews are cheaper, but do show aberrations towards the edges. I wrote up a quick comparison of the Altair UFF and Superview 30mm here. The 24mm UFFs are in 1.25" format, hence the limitation on the field compared with the 2" EPs. Some more discussions: https://stargazerslounge.com/topic/400497-wide-field-eyepiece-for-fast-scopes-any-suggestions/#comment-4295371 https://stargazerslounge.com/topic/403780-celestron-ultima-edge-30mm-apm-uff-stellalyra-uf/

Sounds like a good evening. I think you meant to type "M3 was underwhelming"?

The "postman" left his red van at the depot today, and instead arrived in a Caterham Super 7 to deliver these for me (accompanied by a helper). These are my first binos, so I'm looking forward to a new experience. (The BBC thinks there may be some clear spells tonight, CO says no chance)

I hadn't realized he was still with us, until I saw that he wasn't. I expect many will have heard of Moore's Law, even if they couldn't remember quite what it said. https://m.slashdot.org/story/412369

That's understandable. Start by getting to know the sky, the way it moves through the evening and changes from week to week. Even if you have the scope out on an evening, spend some time just trying to identify the more obvious constellations with the naked eye. If you have some binoculars, try sweeping the sky and see what you find. As you get to know the sky, you will be better placed to navigate with the scope and find objects that aren't as obvious as the planets. There is plenty that you can see with a 150p. https://britastro.org/2018/star-hopping https://lovethenightsky.com/what-is-star-hopping/