Martin Meredith

Ah, you're right, no it doesn't. ROI is implemented at the point of capture at present (in fact, I use the zwoasi function to set the ROI). It is possible in principle to do it with incoming subs but it will be important for consistency to do it prior to the main capture ie using framing subs, which doesn't necessarily fit with Dan's workflow.

I may not have transferred all the doc across to readthedocs, but it is described in the older version of the docs here: https://transpy.eu.pythonanywhere.com/jocular/# Essentially, ROI applies to the view you see in the 'eyepiece' at the point at which you click the ROI icon, and continues to apply until you click ROI again. The only thing to be careful with is that there are enough stars for stacking purposes, since ROI throws away anything not in the view. This is the relevant passage: Jocular implements region-of-interest (ROI) as follows. First, use a framing capture and the pan/zoom/rotate options to get the object just how you want it. Then stop the framing capture and click on the ROI icon. Any subsequent captures (for the current observation) will be restricted to that region. Click ROI again to see the full sensor. Note that currently you need to set up any binning options *before* choosing the ROI.

Thanks for this info. I'll see if I can add an option to specify a certain flip on load if this header is present. Martin

Hi For 'official' catalogues I tend to rely on Vizier. For instance, the WDS is here: https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=B/wds&-to=3 You could then either download it all in an appropriate format and use a spreadsheet to select the entries you want, or use the filters on the Vizier page itself to select them. As far as Collinder is concerned, I believe some would be visible with binocs; they tend to be very large. I have my own versions of most of the DSO catalogues in comma-separated value format if they're useful. I'm attaching the open cluster example to see if of any use. Let me know if you'd like the rest... cheers Martin OCs_new.csv

Hi Mike It is currently possible to use OSC via the watched directory approach by selecting a non-mono colour space, but isn't yet integrated into native capture, so you would have to use a different capture program and then feed the subs into Jocular. I really ought to modify the ZWO native capture side so that it also does this for direct capture too -- this might happen in the short term. The way it works is to split each incoming OSC sub into R, G and B subs, and then proceeds as if they were coming from a mono camera plus filters. This isn't really ideal, but Jocular was designed for LAB colour space rather than RGB, so it would need a reasonable amount of work to do things differently. It might happen in the future, but not in the short term. cheers Martin

Mike, if you reload, platesolve, and turn up the annotation slider to max, it ought to show the group members (as red squares). The squares might be hidden beneath the galaxy annotation markers so you'd need to click on those first to see the red squares... Martin

Thinking more about this, I think the only way it is going to work is for the orientation to be embedded in the FITs header. The reason is that when you reload the subs at any point in the future, you would have to respecify the flipping point every time, which would be supremely tedious. Maybe the software you use for capture already does this? If you send me a FITS file (not a Jocular-created FITs) I will check the headers.

No, that won't work I'm afraid. Flipping is only done as a final step prior to display rather than when the subs are coming in. I could add a 'flip on input' I suppose but I'd need to think thru any ramifications elsewhere.

Thanks for the reminder about the David Lukehurst platforms. The website says they're prototypes, but I think it has said that for some years now. Even so, it would be interesting to hear from anyone with practical experience of them. Weight and simplicity of setup is the main attraction for me. Simply plonk down a 5 kg platform, level it and set it pointing north (no need to actually see Polaris), then add the 10 kg Dob base, then the 10 kg Dob tube (for the 8" model), and get EEAV-ing (of course, there is still mirror cooling to consider unless the scope is kept at ambient temp)

Yes, I've seen some of the early ones from Tiago. I suspect it would work if the platform is up to it. Unfortunately the Asterion platforms are currently unavailable. I'm not sure why this option is not more popular. Taking for instance an 8" scope (say the Quattro that I have) and a the smallest suitable mount (heq5-pro), the total cost is around £1650 incl. power supply, and the weight is 37-40 kg depending on power supply. The 8" Starsense scope plus EQ platform is around £920 and the total weight is 25 kg. The main difference is that the former has goto and the latter has push to. I guess also the Starsense is not designed as an imaging scope, but it could be made to work especially with a small sensor camera. Besides reduced weight and price, the pros of the EQ platform approach that I see are: easier and faster to setup/takedown/align for observing (saving perhaps 15 mins each session assuming one doesn't have an obsy); easier and more natural to use in visual mode; takes up less storage space. Cons: resetting the platform every hour. Any other pros and cons? It is quite tempting. Perhaps it is time to sell the Quattro/Az-EQ6 combo...

Maybe if you save it as a delimited ASCII file you could import into a spreadsheet and sort from there?

Very interesting, and certainly looks like it has an outer ring (also in the SDSS image, though nowhere near as clear as yours), and it is rather odd that there is no (r) in its morphological classification. It seems possble to me that it has been overlooked. BTW You might find some useful info on the fraught question of what defines a ring galaxy on this thread, as there are various types:

Interesting question, and one that I've also been pondering on and off. I'm not sure if these thoughts are useful to you or not, but as you say it is a nice conversation piece, so this is my take. Current setup: I've used an alt-az mounted 8" f4 (=800mm FL) Newt for the last 7 years for EEVA coupled with a small sensitive mono camera (Lodestar X2 mono or ASI 290MM mini) plus filterwheel to generate colour or explore narrowband. I haven't been tempted to go bigger in either aperture or camera size in all that time, because for me this setup allows me to capture almost all objects of interest at a decent resolution when seeing is good. I really like this setup and it has served me well for 1000s of observations, but either it is getting heavier or I am getting older... If I were to start again from scratch, I might therefore consider going a little smaller in aperture. I wouldn't go smaller than a 6" Newt though, because I like to see detail in small galaxies and PNs, and I'd stay fast, because a 6" f/4 Newt is a pretty short and light scope that would mean I could dispense with my heavy EQ6-class mount. An alternative that I've been thinking about recently is something completely different: an 8" (or 10") Starsense dob on an equatorial platform. This combination removes the need for a heavy driven mount altogether (and also simplifies the entire process since there is no time-wasting 2-star alignment, which I find tedious). Overall, this would be a lot lighter than my current setup. My only concern is whether the tracking is good enough for EEVA at this focal length. Someone needs to take the plunge and test it 🙂 This kind of scope would serve double duty as a visual scope, where the EQ platform would also help a lot. As you can see, I like Newts, probably because my earlier EEVA experiences were plagued by chromatic aberration... Martin

Very odd. If you PM me the most recent log file in your joculardata logs directory I might spot something going on... (or you might see something in there yourself).

Hi Dave Quickstart is useful for exploring the interface with previous captures but the place to look is the live observation page: https://jocular.readthedocs.io/en/latest/liveobservation.html Basically, this will tell you to click on the telescope icon (at around 2.30 on the interface) and choose the ASI camera option. If your camera is plugged in when you click connect it ought to find it. This is a one-time-only setup. cheers Martin

What errors do you get when you try to install? It may be that one of the dependencies requires 3.9 or lower (I'm running 3.8 myself).

I must say, Bill's suggestion of the meaning of offset makes a lot more sense to me. The bright star may be ambiguous, whereas the galactic centre is not. Perhaps the size of the offsets will indicate which of the two possibilities is most likely...

I see mentioned on the URL Mike provided that people are sometimes asked to provide an offset from the nearest star to help with identification. Maybe that is it? Martin

What happens if you disconnect the mount altogether? Do you get the same or a different error from Sharpcap? If the error is different, that at least will tell you whether Sharpcap is able to see the mount. From the stack trace it doesn't appear to be able to, but it is worth a check.

I use astropy but I've not used showtable. I just had a look for it on my Mac (using 'which showtable') and found it the bin directory of my miniconda distribution. I'm not sure if this is from astropy or something else, I have so much stuff on my system... I'm not a windows user so don't know how you search for commands (maybe 'which' works for you too), but in any case it looks like it either isn't available because it hasn't been downloaded with astropy, or it isn't on your path.

The showtable instruction is used from the command line, not the Python interpreter. i.e. open a new shell and type showtable etc cheers Martin

Thanks Dan! I'm glad you find it useful. I mainly wrote it for my own ends since StarlightLive -- which also did live multispectral combinations -- wasn't being developed further.

Beautiful galaxy with unusual dust lanes that I find hard to get my head around. I observed NGC 660 last year and rather than posting the main galaxy, which is also taken with a Lodestar and 200mm scope and quite similar to yours, I noted that in the lower left of your shot there is a curving chain of fainter galaxies that nevertheless show some interesting structure. The left hand pair appear to be interacting but the distance estimates are very different. The leftmost one is supposedly at 1.88 billion light years distance (mag 18.3) while its visual companion is mag 17.2 and at a 'mere' 782 million LYs. It is more likely to be part of a group with the obvious near face-on spiral (mag 16.3, 779 MLy). Finally, the rightmost galaxy is mag 17.7 but closest to us, at 642 MLyrs. Assuming all these to be correct, we're not looking at a group at all but an orderly progression in distance from right to left. There are other fuzzy spots in the general area that I don't have data for.

Lovely collection of Pegasus Hicksons (always a harbinger of autumn). Stephan's is a particular favourite of mine (see avatar 🙂). You've managed to capture the long wisp that runs from top-right to lower-left of the group. As you say, great shot from the James Webb recently.I checked it out to see if the wisp ran on much more than in this image, but no, its more or less as you caught it and all the more remarkable for just over 3 minutes exposure. I also read that the lower left galaxy (I think its that one, from memory) is now definitely a foreground coincidence, as was long suspected. So really one has to imagine the group sans that one -- still rather spectacular.

Hi Jim It sounds like you've already gone quite deep into the subject, so much of what I'm saying is probably not new to you, but even so this is the approach I would take... To start to narrow down the choices, I suggest you define a lower and upper bound on the field of view you need. Too small a FOV and you end up having problems getting the object on the sensor in the first place, then finding enough stars to stack or platesolve. My 800mm focal length scope paired with an ASI 290 provides a FOV which I think is borderline too small, at around 0.4 x 0.23 degrees; my Lodestar is around 0.34 x 0.44. Your 1200mm scope would be proportionally smaller for these sensors, which would make them tricky to use. At the other end, you really need to consider the kind of DSOs you want to view. This will define the maximum field of view to aim for. You mention planets, galaxies and nebulae, which represent a huge range from the very small to potentially very large, with galaxies in the middle. If you want to do all of these with your current scope you're going to need a large sensor or reducer (as you mention). Its a fact that almost all the interesting DSOs/groups of DSOs out there will fit easily in a 0.3 x 0.4 degree field. Apart from nebulae and some clusters, there are only a handful of galaxies that can't be observed using this FOV. This is probably the hardest thing to get 'right' because when starting out there is a tendency to plan for all interesting objects (perhaps with a bias towards the Messiers, some of which are large), but if you really get into EAA you'll most likely end up drilling into the NGC/IC/Hickson/Arp catalogues, pretty much none of which need a large FOV. The majority of observing reports posted here have FOVs in this general ballpark, and you can see the variety and number of different objects that have been captured. As Mike says, no scope or sensor can do it all, and my preference is to dispense with the larger objects! Its also worth spending some time looking at the entries for the monthly EAA challenges on CN because you'll see the same objects (both showpiece types and less frequently observed stuff) captured with many different scope/sensor combos, so will judge for yourself what kind of FOV is likely to appeal to you. An alternative plan is to use the same camera but with a different scope (e.g. a small refractor with a focal length of around 300-500mm) to capture the larger objects. On the monochrome versus colour question, most galaxies don't benefit from colour at the timescales of EEA observing (a few such as M82 do), but in my opinion all open and globular clusters, and planetary nebulae, do benefit from colour. Mike mentioned my Jocular software, but its worth pointing out that it doesn't really support OSC cameras in any meaningful sense, so Sharpcap or ASIlive would be better options. Again, just a few opinions. It would be good to balance this with some input from nebula aficionados! Martin