Zermelo

Well, finally some stars! I think (just to prove me wrong) CO was actually not bad this time (although this forecast was only from yesterday lunchtime, to be fair it had been promising some clear stuff on Wednesday for several days) There was a bit of low cloud came in just before 22.00 but it cleared away and I managed to carry on until 23.30, when it really did close in. But most of the time, it was completely clear. Meteoblue turned out to be too pessimistic: Whereas Nightshift (on my phone) had forecast "excellent", which was fair enough (the seeing wasn't good, but the breeze settled down after a while).

You're saying you've never seen the moon executing its retrograde motion? It happens once every 17 centuries, on the Friday after the fourth blue moon of the year.

Hi, so your Celestron is a 70/700 refractor. The 700mm focal length means that your 20mm eyepiece gives you a magnification of 700/20 = 35 times. That's not going to show you very much detail on planets; you'll see the rings of Saturn (when open, like now) and the four largest moons of Jupiter. Also, be aware that Jupiter and Saturn are not well positioned (Sagittarius) for Northern hemisphere observers at the moment. The lower they are in the sky, the more difficult it is to observe them - there is more atmosphere in the way, and in many locations there is sky glow from artificial light near the horizon. Mars is better positioned, higher in the sky and not far from its closest to Earth. But Mars is a small disc, and with low magnification you are not likely to see any detail. The other limiting factor is the "70" in your 70/700 specification - the diameter of your main "objective" lens. It's this that determines how much light you are gathering, which in turn limits how much you can magnify an image while remaining useful (it also places a limit on the amount of detail you can see). Planets are bright objects so they will stand a good deal of magnification without becoming too dim - the limits are more likely to be set by other constraints. One factor is how favourable the observing conditions are; if the air is turbulent, or humid, this will make a magnified image too unstable to be useful. The elevation of the object also matters (see above). Another factor is that your refractor will introduce some "colour fringing", especially on brighter objects like planets. This will degrade the image to some extent. A rough guide to the maximum magnification you can expect is to double the size of the objective (in mm) - so 140 in your case, for which you would need an eyepiece of focal length 5mm. Note, this is the maximum achievable under excellent conditions - in practice, you will usually be limited by the other factors. I see your scope also comes with a 4mm eyepiece. I too own a 70/700 refractor which came with a 4mm. I found that in most situations it was not usable - it's just asking too much from a scope like this, and in addition, eyepieces supplied with telescopes are rarely quality designs. I'd suggest that you should be aiming for something more like 100x, which won't be too much for your scope and will show a bit more on planets, when they are suitable. That would be around 7mm focal length. As pointed out above, you could get this either with an eyepiece on its own, or with a different eyepiece used with a "barlow" - for example, a 14mm with a 2x barlow. You could then of course use the 14mm on its own, which would give you a useful 50x mag. Or something close, if those exact lengths aren't available in the range you're considering. As mentioned by Jiggy 67, the BST Starguiders are good value for money and will be a noticeable improvement on the eyepieces that came with the scope (but may be known by other names in the US - possibly "Astrotech Paradigms"). Though you may be in for a wait for any order, as almost all suppliers seem to be out of stock due to Coivd. Do persist with your 70/700 - I saw a lot with mine - but you may need to manage your expectations as far as planets go.

Hello Maggie, another vote for Turn Left at Orion. If you're still not convinced, have a look at a preview on [your preferred online bookseller], or see the accompanying website, which includes downloadable lists of the objects mentioned in the book. You haven't said much about your context, but if you have significant light pollution at your normal viewing location then you might also like to look at The Urban Astronomer's Guide. It covers the same kinds of introductory topic as other books (types of telescope/mount/eyepiece, useful accessories, software, major suppliers, observational techniques) but from the perspective of an observer in a polluted area. The majority of the book is a seasonal guide to objects that can be seen (sometimes only with a fair bit of persistence) from such locations, using a modest telescope. The selection is aimed at northern hemisphere observers, though note the author is american, so with any luck you can ignore the advice on how to avoid getting shot by any police who come across you in a lay-by at 1 a.m.

Welcome to the forum Katie, it sounds like you've made a great start in (a) getting a scope that is right for you and (b) that you're enjoying it (and amazingly, some clear weather at the moment). If you look at the locations in people's profiles, you'll see that quite a few are based in urban locations, and it's surprising how much can be achieved from bright spots. If you're interested in quantifying your level of light pollution, this website will give you an idea, and may be of some use in locating nearby "dark sites" (it's not perfectly accurate as it's based on satellite data, but it's close enough). You'll find people here discussing their own pollution levels either as "SQM" (a scale where higher is better, and 22 is as dark as it gets) or more commonly on the "Bortle Scale" (1-9, with 1 being best). The overall light pollution level is mostly determined by nearby urban areas but, as in your situation, it can also be impaired by individual lights. The old-style low pressure sodium street lights (the dull orange ones) are a bit easier to handle, as a simple filter in your eyepiece will remove most of it without affecting the overall view very much. The bigger problem are the newer LED lights, which are very white and generally far too bright. There are no really effective ways of dealing with these. Some forum members have had success in persuading their local authorities to install a directional shield to stop stray sideways light. Depending on the positioning of the lights, it may be feasible for you to arrange some kind of screening. I got hold of some curtain blackout lining and made up some movable screens. Even with a decent sky and no moon, nearby lights do make a difference, especially when observing fainter objects (like galaxies) because even looking at one briefly will ruin the dark adaptation of your eyes for 20-30 minutes. You might also be interested in this zoom seminar on Sunday dealing with the topic of light pollution - Bob is an excellent speaker. Another tip is to look up some local astronomy clubs. They usually have a wide range of experience levels and often have people who are willing to give advice for new starters. You may even be able to try out other scopes, eyepieces or filters before splashing out any more cash. Happy viewing. [EDIT] A couple more current threads about various aspects of back garden light pollution: https://stargazerslounge.com/topic/363938-diy-street-light-screen-for-obsy/ https://stargazerslounge.com/topic/364657-neighbours-security-lights/

Welcome Dario. Your choice sounds a good one for your needs. It looks like you've already found your way round the forum, but if you've opted for a Mak then this might be worth a look if you've not already found it.

Probably a bit basic for you, Michael, but I've been using the list from the Astronomical League double star observing programme as my "master" of the easier doubles. I have downloaded a copy of the Excel version and keep it sorted in RA order as a rough guide to what's available at any time of year, and mark off each one I've split. I use SkySafari to plan and drive sessions, so I've imported the .skylist version of the AL list, and then I copy selected targets from there into my nightly lists (with other objects, usually driven by the moon phase). When I'm observing, I check the separation before attempting to locate, to give me a rough idea what to expect, and then when I think I've found it I'll check the info section in SkySafari to confirm (or not). I'll usually start off with my Hyperflex zoom and perhaps switched to a fixed EP or add the barlow if needed. I add notes to SkySafari, though these are, at the moment, very minimal. There must be thousands of web pages on doubles, but one more that I'd point out (now archived) is this list of Color Contrasted Double Stars.

Forecasts have apparently improved a great deal since the introduction of multi-million pound computers, but I still find them frustrating and unreliable, so I tend to set up speculatively (which I'm happy to do as I have simple kit and a garden site). If you choose to "turn on experimental features" in CO, you get some extra forecast lines that use alternative data sources, and sometimes they disagree with the main forecast. The cloud cover predictions in particular, while obviously critical for us, can be a bit iffy. In the few months that I've been following it, I have found that it copes with predicting UK weather very much like the others (i.e. not great). You really need to combine a specific forecast with an understanding of the overall prevailing conditions. If it's being made in the context of a very stable system (say, a big high pressure area that's not going anywhere fast) then I would trust the forecasts a few days out (but never more than a week). But often in the UK we have the situation of a succession of systems moving in rapidly from the west or southwest. You might see a forecast of a decent night in three days' time, but in practice it arrives in two, or four, or not at all. Many times I've checked a forecast on the afternoon of a prospective evening session, and the actuality has been wildly different. And of course cloud cover is only part of the story, you may get a clear night as per forecast, but have to contend with poor seeing, transparency, dew, ... If you want, or need, to be informed by the forecasts then one option is to consult several and rationalize them yourself. Others include Meteoblue , Accuweather, Weather Outlook and Windy.com.

FLO do: https://www.firstlightoptics.com/offers/hubble-cassegrain-reflector-telescope.html

I've just bought the classic Q myself, but the clouds haven't cleared since. I did choose it on the basis of positive reviews on this forum (and the fact that FLO actually had stock). It's supposeedly a cut above the cheapest ones, being (semi)APO. I would suggest that whichever of those two you go for, the weak link will be the stock EPs (I have both) and you're not likely to notice the quality or otherwise of the barlow until you try it with other EPs.

If you're sticking with Celestron/Starsense line, then I'll leave others with experience of those models to answer, I have none. But in general the answer to your question is that they can, provided your telescope (or rather, its mount, which sits between the telescope and the tripod) has wifi connectivity. This capability comes built-in with some mounts, or if not it can often be retrofitted with a "dongle". In my setup, the mount has wifi, and there is an app from the manufacturer that allows you to use your phone as a substitute for the bespoke hand controller. This includes a catalogue of stars and other objects, from which you can select and use to direct the telescope. However, I've found it convenient to install a second app (SkySafari) on my phone. This provides more capabilities - for example it can display a map of the sky and show me, superimposed, exactly where my telescope is currently pointing. If your phone has an electronic compass built in (mine doesn't) you can hold it up to the sky (the app view will mimic what you see), and get the telescope to "follow" towards the place in the sky to which you are pointing. There are also ways to use PC apps like Stellarium to direct. Of course, the connectivity tech costs extra, but many have found it worth the spend.

Welcome Sophia.

Hi Phil, and welcome. You seem to be ahead of the game in your thinking, as you've assimilated one of the most important messages, that there is no one scope that will do it all. There are several legitimate starting points. Maks are always popular, and the Heritage range are also frequently recommended here for beginners. I have no experience with either of those, but you also mention the 150i, which I do own, so here are some thoughts on that. The 150i has the same parabolic mirror as the more expensive 150P/PL/P-DS variants. It's a decent enough size to see quite a few fainter objects and will stand enough magnification for reasonable views of planets (i.e. for most of the time in the UK, you're going to be limited by poor seeing or planet position rather than the scope). As has been pointed out above, it is quite "fast" at F/5 - so it won't give such high magnification as a mak with the same eyepiece, but that also means it gives a wider field for extended objects, which I have appreciated more. I have been pleasantly surprised at the performance of the main mirror; I was expecting noticeable coma, astigmatism and other distortions but I really haven't seen any (with my novice eyes). A caveat with that - the stock eyepieces are (as is common) not great; the 10mm is not really usable, and the 25mm, while better, has significant pincushion. It was only when I bought some BST Starguider EPs (yes, +1 for those) that I appreciated the real capabilities. So the cost trimming for the 150i has been made in other places. The primary mirror itself is fixed in its cell (but then, that simplifies collimation). There are no mounting rings (there's a dovetail bolted on to the tube). The finder is a simple red dot. There's no handset (phone app instead). And the focuser is a very basic model. The other aim in all this is to save weight, as the mount has a 5kg limit (though the OTA is well inside this). Personally, I think these are effective compromises for the price point. Sizewise I find it very convenient - I can fit the OTA and tripod under my desk. It's very easy to carry, and it will fit into a small car. Part of my decision-making process was the same as yours, that this scope should be both a decent main scope to start out, and a good alternative grab-and-go if/when we upgrade. Possibly the biggest decision is whether to opt for GoTo and/or tracking from the outset. I know there are some who have never found the need for either, and it will add a significant chunk of spend on a first scope. I wanted to share observing sessions with others, and I had found previous experiences with a manual scope a bit frustrating. Tracking is handy when switching viewers at higher magnifications and, while I would have been prepared to spend a bit of time finding objects from scratch, having GoTo was very convenient to minimise the waiting around that others have to do. I certainly wouldn't say these are essential - there are many who do without them. As for the particular flavour (SynScan) that comes with the Star Discovery mount, it was not an entirely smooth experience. A proper set of instructions took a bit of finding, and it took me a while to get the hang of it. I still occasionally have nights when it all goes wrong. But overall I find that the SynScan app works well, and is accurate enough when I've aligned properly. I find it particularly powerful when combined with SkySafari. The other feature I use a lot is the dual encoding ('Freedom Find'), which allows you to position manually without losing the alignment. Budget at least for 2 or 3 eyepieces and maybe a barlow. In my case, I've also added a Telrad, which has been invaluable, and an illuminated reticle eyepiece. And good luck with getting hold of anything in these covid-challenged times!

OP said 40mm and 13mm

Hello Timothy, apart from planets, can you remember any of the other objects that were in the Tour? I'm wondering if the alignment was so far off that they weren't actually in the field of view, but that sounds unlikely if you were using a 40mm eyepiece and saw Mars - did the scope position it near the centre of view, or did you need to adjust significantly?

Welcome. Also, bear in mind that - in spite of all the planet "action" at the moment - Jupiter and Saturn are not especially well placed this year. They are quite close to the horizon, so the atmosphere affects the view detrimentally. Mars is much better placed at the moment, but even after its close approach it's not easy to see a lot of detail in a beginner scope. Planets generally need higher magnifications, which among other considerations will be limited by (a) the size of the scope's objective (e.g. mirror diameter) and (b) the seeing conditions (very variable, if you're UK based). It's partly about managing expectations. Having said that, my first view of Saturn as a child was through an inch-and-a-half refractor, and was enough to hook me. Good luck with whatever you decide to go with.

Hello and welcome. Even without the links to the actual scopes, there are some general observations: - almost all serious astrophotographers use an equatorial mount, because it can track objects using smooth rotation around a single axis - even then, to get really good results on fainter objects, you need a more expensive EQ mount that has finer tolerances and can manage a greater total weight - nevertheless, few things are actually "impossible", and this group on this forum are a case in point - astro imaging is a big learning curve (and not cheap) - if you are just setting out, think carefully whether you want to go straight into it

Ah, here you go: https://www.365astronomy.com/Replacement-Reticle-for-Telrad-Finder.html

If you mean this, then yes, they are available separately, though I haven't found a UK supplier.

Some amazing photos. Almost like the good old days:

Welcome, which scope do you have? Light pollution won't help, but this book has some good advice on technique and suggestions for suitable targets from urban locations.

The 2012 transit of Venus, because I won't see another. From my location there was a short window between sunrise and end of transit. The night before, I set up a small refractor and projection arrangement in an upstairs room, pointed at the eastern horizon. Next morning we got up at dawn and found the horizon covered in cloud, but the sun escaped just in time for us to see the disc before it was over. The thing that surprised me was the size of Venus - I had been expecting to see something smaller.

A Cheshire is an aid to collimating a telescope, like this one for example. There are alternatives, like caps (cheaper) and lasers (usually more expensive)

I didn't get the clouds down here, but seeing was poor (turbulent upper atmosphere, I think). I made out some darker areas, just about.

In the spring, from northern latitudes: https://en.wikipedia.org/wiki/Messier_marathon