General use of DSO Planner

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I am new to astronomy and would appreciate some suggestions as to what settings to configure DSO lanner pro to for a beginner. For example, some deep sky objects are beyond my skill level to find but when I zoom in my screen is cluttered with things that I cannot even begin to see.

DSO Planner had been specifically designed to address this particular question exactly. However, our user base is quite diverse. Many observers are used to the simple traditional astronomy planetarium software user experience, widely represented on the astronomy software market for various hardware platforms. So, we had to introduce some additional features and ship the app with the defaults which supposed to make the transition to our advanced observations planner easier for everyone. But DSO Planner is way ahead of any typical planetarium app!

I would like to share my own approach to using DSO Planner on my Android smartphone for planning the night, finding my objects of interest, and observing them - all with the help of the app.



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I'm rarely planning my night long ahead, as I know for sure that I can do that right on the dark site of my choice in 5-10 minutes after setting up my telescope in the dawn, while dark adapting in my car or in a chair. However, if you plan to include comets in your observing night it would be a good idea to start the DSO Planner beforehand, while you still have an Internet connection. Most certainly you will immediately see a prompt from DSO Planner offering to update orbital elements for them. It'll take just seconds. At the same checkpoint, I would also make sure the DSO Planner is in the Night Mode already, so at the dark site, I have no sudden "blinding accident" opening it in the dark. Sure thing, if you have found an interesting list of objects to observe and it's not in DSO Planner format yet, you should spend some time, prior to the observing night, for entering that list into DSO Planner, but that's a huge subject in itself, which I'm leaving for the future FAQ.


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If that's your first use of DSO Planner, you should register your observation instruments first, using the Settings menu (just tap the button at the bottom of the first screen), picking the "Astro Equipment" item there. One of your instruments must be checked on that list as the default one, along with the set of your favorite eyepieces, which is necessary to display FOV (Field Of View) guides for them and to calculate visibility grades (so, choose wisely, especially, if you plan to do star-hopping using 2-3 eyepieces, so they have widely varying FOVs).


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So, I'm in the field, dark adapting, and on the first screen of DSO Planner. The first thing I do - go to the Airplane mode to conserve the power. The second - turning on the GPS radio to start obtaining my observing location fix a.s.a.p. (Actually, if you still have phone service available on the site - the coarse location, obtained from cell towers, is good enough to use for the app's calculations, but I'm usually too far from any usable service).

Then, I close the Android settings and open the "Settings" module of DSO Planner (the button at the bottom of the Main screen). I would select the "Geographic Location" item and make sure the "AutoLocation" checkbox is selected. If it is already - usually by then I should have my GPS fix ready (just watch for the time of the last known location fix displayed right there, or, sometimes, it might show "current update" message there), so I'm just swiping down the notification bar again and disabling the GPS to conserve the power. The last location acquired will stay put for now.

Sure thing, you don't have to do all of the above if you are on the same location again, i.e. observing from your backyard. Just make sure the location you have entered and named for your home observatory is selected when you go through step 5 below, and skip this step (3) altogether.


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Now, I would go back to the main screen and prepare the brand new Observations List, using the second button "Observations Lists". It usually displays the last list of objects I've been working with. Typically, that's the list from the prior New Moon outing for me, so it's too old to be reused. So, I'm just long-taping an object on that old list and selecting the "Remove All" option from the pop-up context menu to wipe it completely. But, sometimes, I may want to keep a particular list for later use... So, instead, I would see if I could wipe one of the other 3 lists available for selection from the main menu of this module. Personally, I'm using the first list (List 1) for a new night planning, and other 3 for more specific lists of objects (usually for "non-fuzzies", for objects from custom databases, as well as for building compound lists or manipulating custom databases). For example, you can use them to quickly switch between lists created for different instruments (like one for your Dob, another for your refractor, and another one for binoculars), or for different object types, or for the same object type, but having different parameters, e.t.c. the sky is the limit. To avoid confusion, I'm using the Rename function from the main menu of this screen to set some easy to remember descriptions to my lists.


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As the current Observations List is ready to be populated with the new set of objects, I'm going back to the Main screen, and commence the actual planning for the night by tapping the topmost button "Object Selection". Another recent list of objects will be displayed. That's what I had selected for my prior observing night or while tinkering with some databases I have on the phone. On any new night I would usually just go straight down to the "Select" button at the bottom of that screen (it could read "Update" instead, if something has changed in the conditions, e.g. I have updated the location or instrument in the settings - in that case, I just tap it once to turn into "Select" and tap again), which opens the "Select Conditions" screen, and go through the items provided in order to define my preferences for the entire night or for the observing session like the following:

  • I'm considering myself a seasoned DSO hunter, so I usually have all of the object catalogs except those in "Double Stars" and "Comets" sections already selected. The easiest choice for a beginner would be to select Messier and NGC/IC - they provide years of enjoyment and also better represented in DSO Planner, thanks to the NGCIC.org project, which DSO images we have directly integrated into our app, and to the Steve Gotlieb DSO descriptive notes tightly integrated as well.
  • The "Select Search type" is "Primary" by default. The other option is for more advanced tasks of traversing the SQL database using its dedicated request syntax.
  • The "Select object types" usually have all of the items checked. But that's purely personal option (I'm often removing asterisms and open clusters).
  • The "Empty field treatment" is at maximally relaxed settings (first item selected by default), as, for example, there is no magnitude provided for dark nebulae, but I want to observe them anyway.
  • Now the most sophisticated part, the "Primary search parameters" item, which hides another list of parameters:
    • The "Filter Type" option I use is the "Visibility" filter. This is the mode where your selection of the telescope, eyepieces, and sky limiting magnitude is utilized in order to figure if the DSO object is visible (and to what degree) or not.
    • The next item is "Select constellation" this is where you can immediately reduce the size of your list by searching only within a set of constellations (I never used it, but I know people doing that religiously).
    • The "Object name starts with" option is dedicated for working with custom databases, where you can use a special name prefix to group objects in some custom ways. Or you can target a specific object catalog using it (like IC*). Never used it yet.
    • "Object minimal size" - self-explanatory. Never changed it, but could be useful to skip very small sized galaxies, i.e. on a turbulent night.
    • "Lowest altitude". It's recommended to keep it at 20 degrees (default), as the atmospheric extinction is almost unnoticeable down to that altitude, so the Visibility filter will work right. But I love to relax looking for Southern sky globular clusters glowing with delicious "fatty" star disks when they are floating just above the sea horizon, so I'm keeping it at 0 deg.
    • The "Detection limit" is considered the most mysterious item on the list. But, if you think about it as about the quality of the picture view, - it will be intuitive. Just decide how good the visibility of the objects you want on the scale from 0 to 5. If your goal is to showcase some goodies for friends, select 5. If you are a beginner select 3 to 4. If you are a seasoned observer, hunting the faintest glimpses of the distant light in the black LPZ - enter 0.1 (0 is for objects below your instrument's penetration capabilities).

Done with this one (in fact, I'm rarely touching this item, after setting the altitude to 0 once and having the limit defaulted to 1.1, at all).

  • The "Exclude duplicates" is usually On (default), unless you are investigating the identity of the objects from different catalogs. It helps with the clutter when you have a popular object registered in more than one active catalog.
  • The "Time of observation" for me is obviously from "Now" or "Astro Twilight Ends" - to "Astro Twilight Begins" - that's just 4 screen taps to setup.
  • I can change my current instrument right from that screen as well if I need to. Or/And update the location (but my method, described at step 3 above, is better, as in case the GPS satellites constellation is weak, the fix will be there by the time I'm done configuring the night on this screen. So, I'm just confirming that the fix is good and current (or the name of the observing location is matching), the telescope is the one I have at hand, reading corresponding screen items descriptions.
  • And, finally, the last one - "Sky limiting magnitude". That's the magnitude value of the faintest star you could distinguish by naked eye near Zenith. I wish we have an additional button to show the current zenith on the Star Chart and allow to pick that star (just made a note for such a feature), but usually, I'm just figuring that by observing conditions and assigning 5 for a fairly good sky in a better than yellow light pollution zone (LPZ), 6 for an excellent looking sky in the blue or better LPZ, and 7 for an exceptionally clear sky observed in the true black LPZ. But, sure thing, if you'd prefer the true scientific approach, learn to figure that value from the actual sky observation beforehand.

Done with this screen. Just click the Android's Back button and see your Objects Selection list populating with good candidates to hunt for! But the planning part is not over just yet.


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Looking at the new Objects Selection list, I'm making sure the number of objects found here is not 15'000, as that's the limit for this list, so "15000 obj" means that I lost some of the objects I could observe otherwise due to the device memory limitations. Most of them will be Galaxies, the other types contribution to the count is minimal. Thus on a huge telescope, I may consider observing non-galaxies separately (like first), and then make a separate observation list for galaxies only, i.e. filtering them per constellation, per magnitude ranges, etc. But for my 12" I'm usually getting something around 9500 objects found here in a "worst case" scenario. In order to refine that list, you can tap the "Select" button again and correct anything you think will reduce the list conveniently. Just make sure that when you are back to the list - you tap the "Update" button to apply your new settings to the list. Watch for the "Stop" button to the right from the "Update" one, as the little spinner, indicating that the database crunching is in progress, is less visible in the top right corner of the list in Night mode. When it disappears you can continue with adding objects found to the actual observations list you will be using at the eyepiece.

If the resulting list is less than 5000 objects - I'm simply long-tapping on one of the objects and selecting the "Add All to Observation List" item from the pop-up context menu. So everything on the Objects Selection List is copied to the current Observations List, which I have prepared on step 4 above. Keep in mind though, that if the current Observations List is not empty, new objects will be appended to the existing entries (that's, by the way, how you can create complex compound observation lists from multiple unrelated data sources). The magic of the 5000 number is due to another memory limitation, now for the Observation List size. I believe it's a reasonable limit, as even on 10 hours-long night you will have to observe more than 8 objects per minute in order to run it all through. Also, that's a good size to keep the Star Chart's clutter at bay.

In case my resulting Objects Selection list is larger than 5000, I'd usually prefer to modify my search criteria to reduce it as described above. Another option would be to use the Constellation button (ALL) at the bottom-right of the screen to effectively reduce the list by about 40 times, showing the portion of the list for a single constellation. Then I can use the Add all..." the same way, switching the constellation and adding them one by one until I have about 5000. Then switching to the second Observation List and adding the rest.

That's it for the Object Selection screen. It will remain intact through your observing session, so you can always get back to it and add objects as you go. But I don't usually do that, making sure I have the final set of Observation Lists complete.


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Return to the main screen and tap the Observations Lists button to open your final list of objects, that's your plan for the night or the session.

The first thing I do - sorting my list by the "Set Time" using the "Sort" option in the main menu of the list. So the list starts from objects, which are going below the horizon soon. It's logical to observe them before they are gone.

Tap the first row to open the Star Chart with that first object centered and selected.

Note, that by default, the Chart will have the special objects layers system configured to display the NGCIC database regardless of your Observations List data. As the result you will usually have more NGCIC objects on the Chart than you really need (have on your current Observation List), as the only limitation of that independent object's layer is the object's magnitude (that's what a regular planetarium app will do - show some objects on the Chart). The one time fix for that is to open the Star Chart's Settings from the Main menu and select the "Star, object and image layers" option. You want to clear checks in the "Object Layers" section. After that, you should notice a significant reduction of the clutter on the Chart, as only objects visible in your instrument and selected on the Observation List are displayed. These settings need to be set just once to stay in place forever. But if you don't want a hassle of going through the planning interface (it's enough to disable the filter there to achieve the same effect), and just want to see the Chart of DSO's down to certain magnitude - you can use these layers and sliders to draw all of them easily.

The first thing to check on the map is the Time Mode, displayed in the bottom right corner. While you are at the eyepiece, the first word in that corner text you want to see must be "NOW", what means the Chart is synchronized with your Android OS time (and thus with the real-time). If that's not the case, just tap that corner and select the "RT ON" button at the bottom to toggle the Real Time mode and synchronize the Chart view with the sky view.


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So, again, I have my first object on the Observations List selected and centered on the Chart already and want to point my telescope there.

I'm a Telrad guru and usually can hit the spot with it right away, thanks to the advanced Telrad feature of DSO Planner, but the Star Hopping is great fun too, so let's pretend I have neither Telrad nor a finderscope. My only option is the wide field eyepiece... Another side note here. In fact, the finderscope could be considered an eyepiece too, so if you have one - the same technique will do perfectly fine, you just need to add a "fake" eyepiece to your eyepieces database, which would effectively produce a right FOV circle on the chart, corresponding to the FOV of your finderscope. The easiest way to do that is the trial and error. The only caveat is that the crosshair of your finderscope will be most likely useless, as it's out of sync with the crosshair of the eyepiece circle on the Chart (the later is Polar aligned).

Prior to finding and pointing to the bright base star for the star-hopping start point, I would open the selected object's Details screen (tap the left bottom corner, containing object's name) and tap the "Lock" button there. That will prevent an accidental selection of other objects on the Star Chart screen while I'm manipulating it one-handed from an awkward posture behind the eyepiece - very useful. Also, I would turn on the eyepieces circles display in the Chart's main menu if they are off.

Now, using the low zoom on the Chart, I would try to match some bright stars around my object with what I see in the sky, and then point my telescope to one, closest to my object, making sure it's in the center of the EP FOV. After that I would zoom in the Chart to that star, making sure I can still see the EP FOV ring within the screen bounds. That's my star-hopping navigation Chart. Note the dashed thin red line, which will point in the direction of the selected object from the center of the chart, it's the great aid in hopping between the stars to the target. Don't be confused with the Chart being rotated or mirrored (if using star diagonal) relative to the Chart. You can either rotate your phone to match the EP view, or use the special "Rotate 180", and "Mirror" Menu items of the Chart to amend the issue.

If you hadn't done that yet, there is one more step to do prior to starting pushing and pulling the mount. Open the Chart's main menu and select "Boldness" item. You will see two disks on the horizontal guideline at the bottom of the Chart. Moving them along the line allows to adjust sizes of stars' circles on the Chart (it's easier to try and master than try to explain what you need to do with these disks). That makes matching the magnitude differences you see in the eyepiece with the Chart's information much easier. These settings are individual to your Android screen, your eyes, and your instrument, so they always need some initial tuning and may need tuning again, after changing the instrument (telescope, eyepieces set). Each "Boldness" setting is saved per zoom level, so you do have some flexibility here to minimize the need of adjusting that every time, by tuning some reasonable average boldness). As an avid AVSO (variable stars) observer I prefer to simply ramp up the difference between brightest and faintest stars significantly (That's how AAVSO Charts are made on purpose), so I can see the difference clearly, regardless of how realistic the image looks. Besides, it's a map, not a planetarium projection.


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I'm ready for star-hopping now. Looking with one eye to the Chart and with another eye through the Eyepiece, using one hand to push the OTA, and another hand to slide my map along the red line until both hit the target. In case the object is small, I can change the EP and the Chart's zoom to continue hopping at higher magnification as necessary. If I want to make a note of my observations for that object, I would tap the left bottom corner of the Chart again to open the Object Details screen, select the Notes button, then Add new note button in the notes list, and either type something, or hit the Start Recording button and narrate some nonsense to decipher later. Either way, the note must be explicitly saved using the Save button at the bottom.

When done, don't forget to release the Lock on the object, so you can select another one either from the Observation List or right from the Star Chart screen.



Tip: Quite often, I may notice a mysterious glimpse in the vicinity of my target object, it could be another DSO, which hadn't been listed for some reason. I would almost certainly use the "Nearby" menu item of the Chart to research the region further and figure what could it be. Basically, it will search every database in order to reveal any objects close to the center of the Chart's screen and display its findings.


Hope that helps.