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A friend with a young child asked me for a beginner scope recommendation of less than $300 to see the planets as well as some brighter deep sky objects in a relatively dark suburban location. My first inclination is to recommend the Starblast 4.5 using a more novice-friendly Orion 7-21mm zoom eyepiece, but I think a major hurdle for complete beginners like her is not knowing how to star hop to find deep sky objects, and with a child around, patience is extremely limited.

With the current technologies on the night sky phone apps, I thought it might be useful and much cheaper than buying GOTO scopes to attach the phone to the manual telescope, such as a Starblast, to use as a secondary finder. I found YouTube videos about apps:

(Sky Safari Pro) or like this
(advanced app), but I don't know if amateur astronomers actually use the phone as secondary finders now. (Since I was last active with an astronomy club over 15 years ago, before any night sky phone apps became popular!) I searched online, but most web pages are not recent. So I am writing here. Do people now attach a finder-app loaded phones/iPads to telescope bodies as a secondary finder? If so, what apps do they use and does it work well (does it need frequent realignment)? I'm thinking of using a bunch of masking tape to attach the phone to the Starblast, or are there piggyback mounts I can buy for the Starblast?


If the above is not an option, I did find the Sky Safari Pro tutorial,

, where you hold the phone/pad with this app to help guide the manual telescopes to find the objects, where the biggest advantage in star hopping is that the app can flip the stars as they are shown in the upside-down view through a Newtonian scope like Starblast. For people who have tried the Sky Safari Pro tool holding the phone/pad on their hands to help with their manual scopes locate objects, is it easy to use and helpful in the field?

Are there other recommended apps helpful in finding deep sky objects?

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    $\begingroup$ Also check out the Astronomers Without Borders OneSky 5" reflector - a good alternative to the StarBlast $\endgroup$ – Aaron F Nov 12 '20 at 21:45
  • $\begingroup$ "the app can flip the stars as they are shown in the upside-down view through a Newtonian" - a paper star atlas can also be easily rotated 180° :-) $\endgroup$ – Aaron F Nov 12 '20 at 21:47
  • $\begingroup$ I think the appeal of the app is it tells you exactly where you're looking whereas a map still has a learning curve for people who don't know the constellations. :D $\endgroup$ – HaoQi Li Nov 13 '20 at 3:10
  • $\begingroup$ that's true: being able to zoom in and out at will makes a massive difference to usability. The most annoying thing with the phone is the screen brightness: you need a physical red filter, because: even with a screen filter app, the app can't overlay its filter above operating system elements, so it's easy to get flashes of bright light from the lock screen or a notification which appears; and when that happens you have to wait for your dark adaptation to return and it's very annoying. Of course, from the bright city sky where I do most of my observing, I use the phone all the time :-) $\endgroup$ – Aaron F Nov 13 '20 at 9:49
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You can do this. It's possible to mount a phone on a telescope and use it as an electronic finder with an app like Sky Safari or Stellarium Mobile.

However:

  • The accuracy of it very much depends on the accuracy and sensitivity of the phone's sensors, and this varies quite a lot between phones
  • If the telescope tube contains ferrous metal then it'll throw off the magnetic sensor
  • The light of the screen adversely affects your eye's night adaptation

These things may or may not be issues depending on each individual situation.

I've tried it a couple of times but never been happy with the results. The two phones I tested weren't accurate enough.

Some people do use their phones as finders, but they tend to do it with digital setting circles (DSCs) such as the Nexus 2. This has a pair of 'encoders' which you attach to your telescope, and these are used to track the movements of the telescope's axes, and update a mobile application accordingly.


Personally, I use a Telrad non-magnifying sight to get myself in the general vicinity, then move over to a magnifying finder scope, and finally to the eyepiece.

I star-hop using a combination of three, depending on my target. A lot of the time I can go straight from the Telrad to the eyepiece. Other times I'll star-hop with the finder telescope.


If your friend is short on available observing time, then it can help to plan sessions beforehand: a list of targets and directions to them from the nearest brightest recognisable star.

A program like Kstars can be used to assist with this: it has a star-hopping planning tool as well as a "what's up tonight?" tool.

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  • $\begingroup$ Thanks! Have you used Kstars Lite on a phone/tablet device? I looked at the Google Play reviews, there are a lot of reports of crashing and only a 2/5 stars. $\endgroup$ – HaoQi Li Nov 13 '20 at 19:10
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    $\begingroup$ @HaoQiLi I have, and it's not very good unfortunately. I figured out that you can work around the crashing problem by manually granting it the permissions it requires (storage and location). But I found it lacking in features compared to the desktop version, and there's too much bright white in the menus - even with the "Night Vision Color Scheme" selected. I mainly use Stellarium+ and SkySafari Plus (this goes on sale a few times a year, by the way). I find SkySafari more detailed and Stellarium less cluttered. Stellarium also has a version which works in a web browser and works well. $\endgroup$ – Aaron F Nov 13 '20 at 20:44
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    $\begingroup$ @HaoQiLi stellarium-web.org $\endgroup$ – Aaron F Nov 13 '20 at 20:46
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One app that hasn't been mentioned is 'a pair of eyes' assisted by a brain ;-) Why not learn one's way around the sky simply by seeing it? It is a highly interesting and very enjoyable process. I did this as a child and soon became familiar with all the constellations (even some that were too far south for me to see from the UK). Children are also usually interested in the stories behind the constellations, names of the stars and so on. Using a pre-written app doesn't encourage you to learn because the app does it for you. It's worthy of note that many professional astronomers do not know their Scutum from their Sextans (I know this for a fact; it's not opinion).

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