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Selecting targets for a session


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Being still quite new to this, a few nights ago, having picked a couple of targets and getting the obligatory pics I kind of found myself thinking,  "so what next"?

So I was just wondering what seasoned EEVAstronomers do to maximise a session?  Do you preselect targets of the same type,  or in the same constellation... or just go with the flow? 



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Simply put you need to decide what it is you wish to 'see' and find out about .

There are many categories/lists.

Messiers Objects. Caldwell Objects, Herschel 400, Brighter NGCs (about 400 of them), Planetary Nebulae, Globular Clusters, Open Clusters, Reflection Nebulae

Hicksons, Arps, 

SHK galaxy groups, VV galaxies, Palomar Galaxy Groups, Palomar Compact Galaxies, Flat galaxies (RFGC), WBL Galaxies, Distant IC/NGC galaxies, Quasars.........

Personally I tend to stay in small areas of the sky so as to be able to ensure my set up stays well aligned for that area.

I am intrigued by your phrase "obligatory pictures".  EEVA seeks to continue the tradition in this hobby of observing and finding out about the object to build up a personal knowledge of the amazing universe, as well as sharing what we 'see' and also the understanding we gain. I regularly go back to objects for another look (do that visually as well). I fear you may get bored if you see things as "obligatory pictures"

You will see that some specific threads have been set up in the EEVA sections- Arps, Hicksons, VV Galaxies, Globular Clusters. (resources provided at the start of these threads as appropriate). If there is a specific interest that grabs your attention then a thread could be set up for it, to which we can all contribute.

Obviously you need to choose objects that suit your set up as well as your interests. Various software can generate lists for the night - free or otherwise. I would be happy to generate lists in excel if that helps. Probably best to think in terms of objects brighter than mag 12 - a few hundred of them.

I and others can supply lists. Currently my galaxy lists run into several thousand!!!!! - I shall never complete them. Sometime I will make up my own personal Messier Object booklet as something to look back to when age finally prevents me getting out there........I have done this for the Hicksons and the Arps.

Certainly it helps to have pre prepared lists to maximise our limited clear spells.

Have fun


Edited by Mike JW
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I think learning some more about each object is a good. Until now I've been more interesting in seeing things and taking a snapshot as a record and then moving on. Gaining a deeper understanding of each object and maybe some discussion around it (on here) sounds like a great idea. I'm short on time for now but appreciate your reply and will come back to it again later, and will take your advice on looking at the other threads. Thanks always for your inputs, much appreciated!

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Hi Greg

This is a big question and a very interesting one, and one that I hope will provoke some discussion.  All I can do is recount some of my own experiences.

When I first started out in EEVA I spent a few sessions observing well-known objects such as M42, M46 and the like (it was Jan/Feb) and then galaxy season swung around so I turned to looking at well-known galaxies..... but at some point soon after I realised I was capturing much fainter stuff too, and from that moment it became a question of pushing the approach to its limits, and that feeling has not gone away. I obtained a copy of the Night Sky Observing Guide (NSOG) and found that I could make out all the details reported in 20" scopes with my 8" reflector. I suppose this was all part of a long 'calibration' process, to decide on what the boundaries of the technique were for my context. Alvin Huey's guides (mainly free) as well as Reiner Vogel's Hickson guide (free) were all very useful during this stage.

Once I had an idea of the capabilities of my setup, I was amazed to find that the number of potentially interesting objects ran into tens or hundreds of thousands. I guess I spent the next 12 months or so gorging on different object types in a semi-haphazard fashion, looking at faint quasars and Abell galaxy clusters, Hicksons, Shakhbazians and the like. There is an overwhelming amount of 'stuff' that can be done with EEVA and I certainly appreciated the need for some structure.

These last few years my whole process has become (slightly) more organised in the sense that I have a number of lists active that I am trying to work my way through.  There is a lot to be said for looking at objects of a given type or class. It is unfortunate that we sometimes talk about 'trawling' or 'working our way' a list of objects like the VVs or Arps or Berkeley OCs or whatever and this might give the impression of cranking the handle to the next one of its type, but I've found it isn't like that. When it comes to observing many objects of the same type, I have come to the conclusion that the whole exceeds the sum of the parts. Mike's globular cluster thread is a great example of this and I've found the same when I've focussed on one object type, or one catalogue. Yes, some exemplars are underwhelming (to look at, not necessarily to read about), but these just prime the 'wow' factor when a compelling example of the type comes along. This happens very often. I might start the night with a list of 20-40 objects to potentially look at (and in a good long session I will observe no more 20),  but I find it impossible to predict in advance which will be the 'object of the night' for me. Some innocuous NGC 4-digit number suddenly transforms into the most wonderful object, or the main object of interest is instead relegated because of that amazing 16th mag flat galaxy in the corner of the field, or an interesting colour combination of stars amidst a galaxy cluster... impossible to predict. And by building up a collection of observations of a given type, the astrophysics becomes more intriguing (why is this a barred spiral, what does this Trumpler classification mean, etc) and the contrasts between types become more obvious.

In terms of planning a session, even the best printed guides only cover a small percentage of the 'available' objects so at some point it is worth acquiring other planning tools. I developed the PrettyDeepMaps explicitly for EEVA as I found that the charting apps available to me (on a Mac at least) did not go anywhere near deep enough for the capabilities of EEVA. For instance, I don't know anything else that plots all the individual Shakhbazian members or the like, although things might have changed since 2015-16 when I produced the charts. Although they are all PDFs, the maps come with a set of tables that can serve as a planning tool since everything is hyperlinked to everything else. Nowadays I use these in combination with Jocular for most of my planning since in that way the observing list is integrated into the EEVA tool itself, meaning I can run the sessions with minimal typing, and also because Jocular provides transit times etc that the maps cannot do as they are not tied to a specific observing location. I typically have the charts open on one 'virtual'  screen on my laptop and Jocular on the other and am constantly flipping between the two. For each object on my observing list for that evening I use the charts to confirm its position, get it oriented with N at the top, and look for interesting things in the vicinity, to either frame alongside the 'target' or to visit later. In this way I am easily side-tracked... but in a good/fun way. 

Like Mike, I tend to focus on a small patch of the sky. This patch isn't always 'optimal' in the sense of the right time of year or the best altitude. It is occasionally a lot of fun to head to the deep south to weird constellations like Microscopium. But if I develop a sudden passion to see ring galaxies, for instance, I might be all over the available sky trying to pick them up and compare them, within a single session. 

In sum, to try to answer your question, there is a lot to be said for picking some catalogue or object type and pursuing it (perhaps in parallel with other lists) to see what grabs your interest. This gives some structure to an observing session (and some would say that since all of it is interesting, it hardly matters what we observe!). In parallel, it is worth exploring the limits of your own equipment/context. A fun thing to do is to find a galaxy cluster and see what is the faintest member you can detect, or an open cluster and identify your stellar magnitude limit, or a distant quasar.




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thats fantastic Martin, I really appreciate your detailed reply. Clearly you have a lot of experience in this. Did you develop Jocular, I heard about it before on hear I think. I tried downloading PrettyDeepMaps but the site seems to have an issue at the moment. Does Jocular work on Mac?


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i just found the Jocular thread on SGL, are these the latest files? I have a Mac but AltairCapture Live Stacking & Alignment only works in the Windows version so have been using a Windows pc for now, but prefer to use my Mac. I'm using GPCam2 290C, will this be supported? thanks

Edited by Gmx76
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HI Greg

The maps link on Zenodo in my sig is working at the moment (it is the huge CERN data repository so it should always be online). They're 9G in all but you can download parts. Let me know if any issues. You need a pdf browser that supports hyperlinks (Acrobat is fine in this regard).

Jocular in the version currently available on that thread only supports monitoring a folder for monochrome cameras with relatively small pixel counts (the reasoning is explained in the user guide, but essentially Jocular supports a different model where everything can be reprocessed on the fly, and this doesn't really work well for large sensors). The version that I hope to bring out soon is a major revision with lots of new features, and it will support the Lodestar mono camera natively (and the Ultrastar I hope also), as well as the monitored folder for other cameras. Unfortunately it is a lot of work and outside my programming expertise to support other cameras at the moment (I was pretty surprised I could handle the Lodestar...) but the whole thing is open source and will be on GitHub so there is nothing to stop others adding in support for other cameras. That's the best I can say at the moment.

The one part of Jocular that might be of use regardless of the capture side is the session planning tool (example attached). I might develop a separate smaller application that just handles this side. The new version it supports both supplied and user DSO catalogues and can export observing lists so might be useful to some people.




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Sounds like an endorsement!

I was just replying back to your earlier reply again. I will try these. Think I'm going to concentrate on PNs and GCs for now as I have managed to find and photo a small number of these (with your advice!) and seem like a good starting point. Will try to get list of these from Jocular, otherwise, I may take you up on your offer for some lists, thanks

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Just to clarify that this is a screenshot from the so-far-unreleased version. The older version does have some observation planning built in (it has the same 40k+ object database) but isn't anywhere close to as flexible (no exporting, no alt-az/transit info, no user catalogues etc). I will hasten to get the new version ready to test.... but meanwhile do let me know of any install issues. It isn't plug and play but most of the work is done up front, then later versions ought to be simpler...


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I think it is worth while trying a few of the popular or 'easy' objects first,  to gather experience in the techniques that you need to use. Probably better than trying to delve into difficult faint objects which you might be frustrated in not finding. 

My first goto resource at the moment is the Interstellarum Deep Sky Atlas - it has excellent maps, and the objects are labelled according to their brightness, so you can judge how faint they are quite easily. It is a bit pricey though.
I would normally spend a while looking at a constellation that is well placed for observing tonight (say) and selecting a number of possible targets. As Mike and Martin have said, your scope / mount will be more forgiving if you limit your slews to short jumps from one object to the next (syncing as you go).


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Great advice thanks Callum. I like the idea of picking a constellation that's going to be in view for a good period of the session,  and/or keeping with brighter objects. I have an Az-GTI coming as a birthday present in a couple of weeks so this should help with finding and tracking. 

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  • 1 month later...

Generally I’ve set myself different levels of goals based on my own interests. The first thing that got me into this was seeing AstroJedi on CloudyNights post an image of the relativistic jet in m87 taken from inside SanDiego light pollution. So M87s jet was my first goal - which took some time for a variety of reasons (not having a telescope was the first one...).

I have a list in sky safari that is my “season” goals. I’d have a few of those that were relatively tricky or needed multiple observations (or upgrades in equipment) to get. M87, the Apollo landing sites, pillars of creation, an Einstein ring, gravitational lensing, that kind of thing. 

Then each night I would also have a few objects that I’d seen in books or people had mentioned in the forums and wanted to check out myself, that would be the “evening” goal.

Sometimes the evening goal was something someone had posted - an image that had no detail and I wanted to see more. Sometimes the opposite, images with amazing detail and I wanted to see  how close I could get with my London light pollution. Other times it would be something I’ve read about in a magazine or I’ve heard of in a lecture. 

Lastly, I keep an eye on the transients to see if there are any supernova to check out - if there are that’s usually top of my list.

I will also go with the flow sometimes. I use sky safari to control my mount and if I saw something on the map that looked interesting in the vicinity of where the telescope was pointing, I’d head over to take a look.

There is so much to see that it can seem that there is nothing to see. Picking things at random can show up amazing things you otherwise wouldn’t find, but most of the time I’ve found a lot of things look similar or lack detail from my location. Going with the flow is actually often quite unsatisfying.

The best thing for me has been the forums and books.

The Annals of the Deep Sky by Kanipe and Webb are great. I love the Cambridge Photographic Atlas of galaxies and the Cambridge Arp Cataloge. Sometimes I’ll just get them off the shelf and jump around randomly on the pages and point the telescope to see what I can. Arp is particularly interesting in that respect not just because the objects are fascinating but also because that catalog has all the original plates from (mainly) Mt Palomar observations. It’s fun seeing what a small modern 6” telescope and camera can do relative to what was the biggest telescope on earth with film. Sometimes it’s pretty amazing how close you can get.

Generally I have five or six objects for an evening and spend between 3-30 minutes stacking, mostly about 10 if it’s interesting and 3 if it looks like nothings working. Sometimes I leave the telescope running on an object after I go to bed and reprocess the data to see if I can see more later.

Any time I read something about an interesting object I’ll add it to a list. I don’t have much of a method other than checking those out if they’re near by or in a good position like the zenith.

I’ll also keep an eye on general goings on. Mars, for example, I made an effort to check out on the evenings around opposition (scuppered mainly by weather alas).

I also almost always look at a planet, the moon, or Orion if they’re in the sky too, maybe a globular cluster - either way something easy and bright. If you’ve spent a few hours failing to see anything other than fuzzy noise it’s nice to look at the easy spectacular stuff so that at least you’ve seen something that night.


Edited by London_David
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Its great you have so many methods to build your to-see list for a session. It's a good idea to have some easy targets on hand. For me as a newbie with crummy weather and some new kit to play with,  those precious hours I do get i want to make the most of, so that's a good idea.  Going with the flow can end up wasting a lot of time 

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