Cosmic Geoff

I forgot about the occultation but it was overcast anyway all day.

Having to re-enter the date and time each time you turn it on is normal for a Nexstar. It should retain the latitude and longitude once set. There are plenty of settings to get wrong, any of which will cause it to point to the wrong bit of sky: latitude/longitude, time zone, daylight saving, date format, time of day. I have found that doing a daytime setup between noon and 1pm can also catch one out (should be 00hrs and PM). If the scope points to the wrong patch of sky, I would respectfully suggest that it's telling you the settings are wrong, even if you think they are correct.... These scopes were made for the USA market, so all settings are in US formats. Lat/long setting is also non-obvious and catches out many new users. The current Nexstars do not need to be pointed North (or anywhere else) before starting alignment, with the exception of the Starsense accessory, but an old one with a mount that can be used in equatorial wedge mode may differ. Is the mount being used in alt-az or equatorial mode, and are your settings consistent with this? (My Nexstar SLT has EQ North and EQ South in the menus, even though these seem to have no practical use in an alt-az outfit.) I scrolled through the Nexstar 8 manual you cite, and note that it apparently tells you to start with the scope aligned North in order to locate the alignment stars. AFAIK, Sky-watcher Synscan mounts still work this way, but the recent Nexstar mounts dispense with this and assume that (a) you can find alignment stars yourself or (b) the three star alignment (on three unidentified bright stars) will sort it for you. I wouldn't try updating any firmware before you have got the system to work. Later Nexstars use a different (Nexstar+) handset, but as all the clever stuff is in the handset, if you swap the handset for a later version it will probably work. BTW, a Starsense system might work too (but check the small print). The 5.5/2.1mm power plug on the recent Nexstars is not very good and can cause problems with poor contact. Recently I had the plug on my C8SE shift during a session, scrambling the software, and the same night the OTA started traversing downwards at high speed in altitude, for no evident reason. I suspect the plug again.

ROFL😁! I have one of these - a bigger version of the C5 you mentioned in your first post. Calling it suitable for astrophotography is being a bit economical with the truth. In the form of the fairly portable C8 SE GoTo it's about as suitable for astrophotography as a family car is for the Indy 500. Put that 12.5 pound OTA on a decent (very heavy, non-portable) alt-az GoTo mount in the form of the CPC800 and you have a fine outfit for planetary imaging. Put the C8 OTA on a decent equatorial GoTo eg a HEQ5 or EQ6 (decidedly heavy and non-portable), and you again have a decent setup for planetary imaging, or if you an advanced amateur imager, a setup suitable for imaging small galaxies (though some people may have opinions on how suitable it is even for that). For visual observation of galaxies, for the past two or three years I have made an annual trip to dark Devon with the C8 SE. The portable setup is easy to transport and carry outside, the aperture is big enough for a decent view, and the GoTo mount makes it possible to find enough objects in the limited time available to make the effort worthwhile. I see you are tempted by astrophotography: as indicated above this needs some serious thought. If you want widefield images, e.g of M31 & companions, consider a DSLR on a lightweight tracking mount. Also, I have has some success with a planetary camera attached to a 102mm f5 achro refractor on a SLT alt-az GoTo mount, on a wood tripod, using stacked short exposures. This is a form of EEVA (see the EEVA sub-sections in this forum.) Surprisingly, this setup matched or surpassed what could be seen visually with an 8" SCT.

I have a 127mm Maksutov (about the same aperture as yours) and the images of planets I took with it were sometimes far superior (after processing) to what I could see visually. I suggest you find and check out the "what can I expect to see" thread somewhere on this forum.

Thanks, I expect I can find a box.

Like many people, I tried imaging the Sun's disk on Nov 11. Equipment: 127mm Maksutov, full aperture solar filter, EQ5 driven mount, Celestron Neximage solar system imager camera & ASI120MC camera. My main difficulty was that sunshine/bright daylight and laptop screens don't go together well. I could not see what I was doing with the Neximage at all, so could not get it in focus, and only managed to focus the 120MC on the limb after a lengthy struggle, and then image a part of the sun with Mercury. My question is: how do you experienced solar imagers manage?

I got a really good view of the second contact with my 127mm Mak and full aperture filter. Mercury was sharply defined and black. Tried imaging (sunlight and laptop screens are not a good combination). Eventually got an .ser with ASI120MC and Sharpcap. Sky is cloudy now. (14.24)

I picked up a copy of Philips' "2020 Stargazing month by month guide to the Night Sky" by Couper & Henbest at a discount & remainder store for £3 (reduced from £6.99) It looks like a handy little book, especially for novices, and contains a sky map for each month, monthly objects of interest as well as a listing of the year's special events (conjunctions, etc) and a guide to astrophotography.

Here are the images related to the post above. The images of M1 and M33 may not be the greatest, but I have never been able to see these objects visually even with an 8" telescope. Likewise, the comets are reported to be around mag 11 or 12.

Finally some clear skies on the 7th and I did not have to be anywhere else, so set up my EEVA rig to have a go at three comets, + M33 and M1. Rig = 102mm Startravel achro, SLT mount, permanent wooden tripod and ASI224MC camera. This is not a 'designed' setup, just gear I owned already. With the aid of Precise GoTo, Platesolver2 and some live stacking in Sharpcap, I obtained images containing faint fuzzy blobs for the comets C/2017 T2 (PANSTARRS), C/2018 N2 (ASASSN) and C/260P McNaugt. Turning to M33 (which I have never seen before despite trying on a number of occasions including in rural Scotland), I got a stacked image of some faint nebulosity. Definitely something there but not spectacular. I had likewise never seen M1, but using the gear showed an unmistakable grey oval blob which became clearer with some stacking. Altogether a satisfactory night's work. Typical stacks were 5 x 6sec exposure. Moon - gibbous. Semi-urban sky. Platesolver2 solves in about 1 second on a Dell Vostro laptop.

My EQ5 has RA drive only, + manual Dec drive. I originally intended this for visual use only. I tried it a few times for planetary imaging and it proved to be usable for that. It is orders of magnitude more stable than the SLT mount and tripod and even though the Discovery GoTo mount is a size bigger, the same remarks will apply. A disadvantage of having RA drive only is that it is awkward not having both slow motions in the same place and working with the same feel. Ideally I would prefer GoTo on this mount but I am baulking at scrapping the existing drive and 6v power kit and paying 300 pounds for a GoTo kit.

I have seen a couple of 2nd hand ones, however i have no idea whats good and what isnt. One of them being celestron ps1000 I don't know anything about this telescope except that it seems to be what we call a 'department store' telescope here, and the sales copy claims a maximum magnification of over 800x. This level of magnification is quite unusable in practice, and claims of this sort are generally a cue to run away quickly.

Have a look at 'beginner telescopes' on the FLO (sponsor) website. If you want the maximum aperture for your money, you want the lowest-cost tube design (Newtonian reflector) and the cheapest design of mount (mini-Dob) - hence the recommendations above. Be aware that budget equatorial tripod mounts tend to be wobbly, and also baffling for beginners to set up. Also check out your expectations against small-telescope reality by checking the 'what can I see' thread somewhere on this forum.

You could buy a car jump starter instead of an astro power tank. Something like this: https://www.halfords.com/workshop-tools/garage-equipment/battery-chargers-jump-starters/4-in-1-jump-starter You just need to make sure it has a suitable +12v outlet. There are lots of makes and models of these things and I'd be amazed if you can't find one locally.

A more conventional choice would be a Celestron or Sky-watcher telescope power tank, or one of those car booster/12v cigar socket outlet devices from a car accessory shop. I have one of each, plus a 12v 7AH sealed lead-acid battery I wired up myself.

I think that with a total budget of £200 you are not going to get a telescope that merits much upgrading, or merits a motorized focuser. Unless you get lucky in the second hand market. Around your budget you could get various starter scopes, or as suggested above, a 150mm Dob. I don't see any point in putting a motorized focuser on a Dob. If you got one of the better quality Dobs with tube rings (Bresser?) you would have the option of re-mounting the OTA on a decent equatorial powered mount later. Note that despite various exploits with cameras I still do not have a motorized focuser...

Another effort, on 24 Oct. This time I made a stack of 100 images, which gives a slightly sharper result and (on the imaging laptop) I could see four moons and no interfering stars. Moons identified with the Sky & Telescope tool. Image non-inverted. Taken with CPC800, ASI224MC (and flip mirror).

I should just point out that I put together a 200mm Newtonian and manual EQ-5, and took an instant dislike to it. The eyepiece got into awkward positions, and I had to choose between tripod legs retracted (low objects blocked by fence) and tripod legs extended (needed a cherry picker to reach eyepiece 7 ft above ground for some high objects.) Aiming the straight-thru finder was almost impossible on high objects. I soon bought another 8" scope I could actually use - an 8" Goto SCT. Also you should check out the potential of EEVA (electronically assisted visual astronomy). With this I've 'seen' objects beyond the reach of a visual telescope twice the size.

When I was a youth I made an 8" f7 Newtonian from scratch, including grinding and polishing the mirror. I remember the grinding tool was squares of 1/4" glass stuck on a round wooden disk with pitch. IIRC I was working on a conventional workbench and rotated tool or mirror at intervals by hand. Looking back, I am amazed that I managed it and that the completed instrument worked (I'm not sure how well 🙄).

Here's my not very good image, with the identifiable blobs marked. This image is the 'right' way up, non-reversed. Note that with a SCT if the camera is not looking through a diagonal the image will not be mirror-reversed. Some of the objects in Stevewanstall's image are stars, others are moons.

On 22 Oct I had a go at EEVA with the moons of Uranus, using my CPC800 and the ASI224MC (and flip mirror) The image with about 5 sec exposure looked exciting, with several little dots in a line around Uranus's overexposed blob. But when I analysed it later I found that I had imaged several 13th mag. background stars, and noted Oberon as a definite ID and Ariel as possible. The seeing was bad. The moons are clearly within the range of this setup, so I will try again sometime and see if I can secure a set of stackable images. The Sharpcap live stacking wouldn't work on this occasion. I needed Calsky to identify and eliminate the background stars, but it unhelpfully notes the moons as 'beyond the range of amateur telescopes.' The Sky & Telescope tool identified the moons.

Seems you are talking about 'electronically assisted visual astronomy'. Be aware that this is a field for which no turnkey or off-the-shelf solutions exist yet, though many of us have experimented with various combinations of kit, often to our own satisfaction. From my own experience, I can point out some pitfalls. For the Moon and planets, your students may be under-impressed by the fuzzy, trembling live video view of a planet. A stacked image from the same data will reveal far more detail. It is quite difficult to get a telescope aimed accurately enough for a planetary close-up (e.g. Jupiter part filling the screen), possibly beyond the capability of remotely controlled GoTo. Unlike with visual, you can't change the field of view width. The field of view for a high resolution planetary image is exceedingly small. If you use a wide-field setup (small widefield scope + planetary camera, or longer focal length scope + large sensor), you can use GoTo with some confidence that the desired object is in the field of view. With a minute or so of live stacking, quite faint objects can be seen. I have been astonished at the performance of a 102mm f5 achro refractor coupled with a ASI224MC camera. On a cheap Goto mount it showed galaxies fainter than mag 11 and imaged a starfield including the minor planet Pluto (m14.3). Whether your students will be impressed remains to be seen.

I have A CPC800 and find it is excellent for planetary astrophotography - solid as a rock, tracks well, etc. In fact I bought it mainly for this purpose. As others say, I suspect that putting a CPC1100 on a wedge (etc) could be more trouble than it's worth. You could put it on an equatorial mount, but this would have to be massive (and non-portable). Better to start with the small-aperture ED scope as suggested above. In astrophotography, aperture isn't king.

I actually tried projecting Mercury at the time of the last transit a few years ago. I set up my 102mm f5 achro refractor, which did not quite manage to resolve Mercury's dark dot. I switched to projection using my 127mm Maksutov, which resolved Mercury's dot okay - by now some way inside the solar limb. Lesson one: inferior optics will not be good enough to show Mercury. Lesson two: you can use a 127mm Mak. (I would not advise using any larger aperture telescope). Lesson three: don't use an eyepiece with plastic body elements - they tend to melt if you get the Sun off-axis. Projection screen - you do not need anything special - a white fine grained card will work just fine. If you use a diagonal it saves the bother of making a sunshade for the projection screen - just hold it so the sun does not shine on it.

What camera?