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Is there any attachment or device you can use for a Dobsonian telescope (Skyquest XT6) that can help you localize objects in the sky with ascension and declination?

Using the phone with Skysafari it's quite hard to coordinate with the telescope, as you might be pointing to the wrong object.

Thanks

Luis Wasserman

There are devices and apps.

http://skyeng.com/

https://www.astrodevices.com/Products/N ... index.html

https://play.google.com/store/apps/deta ... n_US&gl=US

https://www.celestron.com/products/star ... er-lt-80az

All of those might be of interest to look into, but Dobsonian owners are often encouraged to learn how to star hop using red dot finders, Telrads, or finder scopes. You have a chance to really learn the sky well that way. It can be very rewarding.

If you don’t have a non-magnifying finder yet (Telrad, etc) definitely get one. Also remember to start your hunt with the lowest power eyepiece you have. If you go looking for Messier objects under a decently dark sky (or even suburban light pollution) it is usually fairly obvious when you have found the object. Start with the brightest ones to get the hang of it. Also start out on objects that are not too near the horizon or the zenith (beware Dobson’s hole), and it helps if there are bright stars nearby, or the object forms a nice pattern with some stars. Star hopping this way will really help you learn the sky.

Both Deane and Kris provided very good advice.

The simplicity of operating a Dob with a "zero power" finder - Telrad (http://www.scopestuff.com/ss_telr1.htm, Rigel QuikFinder http://www.scopestuff.com/ss_rqf2.htm) or red dot finder (http://www.scopestuff.com/ss_rdp1.htm) accompanied by a planisphere (http://www.scopestuff.com/ss_dcl2.htm) and star atlas (https://skyandtelescope.org/astronomy-n ... d-edition/) or even just a current Sky Map (www.skymaps.com) avoids the complications of dealing with learning the potential oddities of computerized go-to mounts at the same time as learning how to find objects in the sky. Locating Deep Sky Objects (DSO's) using charts and starhopping also gives you a better understanding of where objects are located in the night sky and how they change with the seasons.

Digital Setting Circles (DSC's) (small dedicated computers with encoders) as Kris pointed out enhance the ability by providing the Deep Sky Object (DSO) database, and the ability to just enter an object and push the scope to the location, aided by the directions on the DSC's screen. If your scope isn't already equipped with the DSC and encoders you will need the ability to mount them and set them up. But they are definitely worth it, as you don't lose the simplicity of being able to just move the scope by hand rather than having to use the direction keys on the handpad of a computerized scope.

The last item Kris linked is the Celestron StarSense Explorer scope. This system uses your smart phone to use both its gyros and also its camera to take a picture of the sky it's looking at to improve the pointing accuracy over other astronomy apps that just rely on the phone's sensors. Earlier in 2020 I presented at the MAS meeting my experiences of purchasing the lowest cost scope of the StarSense Explorer line and adapt them to my 12.5" truss Dob. I presented on it at the May 2020 MAS meeting. The video and presentation files can be found at this forum topic.viewtopic.php?f=14&t=11569 I think it would be very possible for you to take the brackets from that low cost StarSense Explorer refractor and put them on your Dob in order to use the system. It has its limitations as compared to a full DSC/encoder setup, but it actually works well.

I re-read your question and realized you actually asked if there was a way to equip your Dob with a means to directly use the RA and Dec coordinates. The DSC's definitely do that, but over the years I've also seen articles where people use an inclinometer to determine the altitude and put either an RA-style HH-MM-SS legend or simply a tape measure around the base to determine the azimuth, and use a program to convert the RA/Dec coordinates and (together with the time and date) and convert them to the alt-az coordinates on the scope. That's essentially what the DSC's do, but the DIY approach could be an interesting project.

Thanks, everyone, for the amazing feedback as always. I love this journey as a couple of months ago; I was only seeing Capella.. now I can see Orion Nebula (even though I was not that impressed with either UHC or OIII filters (I bought the lower cost ones Syvonni and Astromania).
I also now look at the Pleiades... for some reason, from my area of town (Eden Prairie), the most prominent stars are the ones towards the East (which I assume has to do with the time I look (8 pm)).

I went back to the May 2020 meeting notice and pulled up the PowerPoint of the meeting presentation and noticed that at least on my Chromebook the pictures for the StarSense Explorer adaptation I presented had gotten rotated and stretched, destroying the context and making the presentation rather confusing.

In case anyone is interested in this approach, I've attached a .PDF of the presentation here which preserves the originally intended graphics.

Also, a couple of note on using the StarSense Explorer adaptation on my truss Dob after more experience...

1. You have to align the phone camera to the telescope in conditions at least light enough to see your alignment target with the phone's camera (the app can sense stars that you cannot see on the screen). Just after sunset is great. One night I had the phone slip a bit after it had been aligned and it was now dark, so I resorted to lighting up the tip of a relatively distant pine tree with my green laser to realign the phone to the scope after dark.

2. The way the bracket is oriented, when pointing very near zenith, viewing the phone's screen can give you a bit of a crick in the neck, as it's angled back from the scope's radial axis. Not much to be done about that.

3. If you plan a long observing session using the StarSense Explorer app, you may want to plug the phone in to a charger to maintain the charge, since the screen remains on during use. Yes, there is a pretty effective red mode available in the app to preserve night vision.

4. We often reference objects beyond the Messier list by NGC number. The StarSense Explorer app is actually aimed more at the beginning observer and only has Brightest stars, Double stars, Asterisms, Solar System, Messier, and Caldwell lists. In order to provide a fairly quick reference to determine if a desired NGC object is available in the Caldwell list in order to find it with the StarSense Explorer, I've also attached a .PDF of a spreadsheet listing the Caldwell objects in NGC order.

luchowa wrote: ↑Mon Mar 22, 2021 10:54 am ... now I can see Orion Nebula (even though I was not that impressed with either UHC or OIII filters (I bought the lower cost ones Syvonni and Astromania).

The Orion Nebula is great without a filter. Perhaps a skyglow filter, but I never use anything else for it.

The OIII is best used in the summer to get the Veil Nebula in Cygnus. Without a filter it is almost invisible. With the OIII it really pops.

luchowa wrote: ↑Mon Mar 22, 2021 10:54 am I also now look at the Pleiades... for some reason, from my area of town (Eden Prairie), the most prominent stars are the ones towards the East (which I assume has to do with the time I look (8 pm)).

Another great open cluster (actually a pair) to look at in the winter and spring, if you have access to the more northern sky, is the Double Cluster in Perseus. NGC 869 and 884, also listed as Caldwell 14. Look in it for the "Cowboy Asterism", which was first pointed out to me by MAS member and Master Observer Greg Haubrich. It's a small semicircle of stars with a brighter star at its center, and opposite the semicircle are stars that can be looked at as his body. The semicircle is the top of the cowboy's head (no hat) and the bright star in the center is the clasp of his string tie.

In the July (2021) Sky & Telescope, in the Astronomer's Workbench column on page 72, there is an article where a person added digital setting circles to her Dob. The article referenced she used DobsonDream4 DSC Encoders from astro-gadget.net on her scope. I went to that web site and I see they have a kit specifically for the Orion SkyQuest scopes. The kits are inexpensive at $149. They use a smart phone or iPad with Sky Safari on them to be the actual controller. Worth checking out!

Suggestions for a larger but portable dobsonian telescope. I see a number of brands that break down. Looks to upgrade from an old 8" homemade one. Something with goto and closer to the 12"+ range. Goto as some nights it is hard to find things with light pollution, moon light, a little haze or windy, etc...star hoping becomes an impossibility. Thanks Much.

I think you mean truss tube Dobs? If you do woodworking and had an interest in converting your 8" to a truss design, you could borrow the Dave Kriege book "The Modern Dobsonian" (now a bit anachronostic, as he wrote it over 20 years ago) to get ideas how to build the conversion.

For commercial truss Dobs, there are Obsession Telescopes (Dave Kriege's company) available in both classic and compact designs, DobStuff.com who makes both kits and completed truss scopes, Teeter's Telescopes (Rob Teeter makes scopes that are truly works of art that perform beautifully), and some larger brands such as Discovery and Explore Scientific. I haven't looked at the Discovery and Explore ones to verify, but the Obsession, Teeter and DobStuff scopes can definitely be equipped with DSC's with or without servos.

Meade also makes the Lightbridge series of truss Dobs and Orion has their SkyQuest XX10 thru XX16 truss Dobs equipped with either DSCs or go-to models.

A main advantage of the Obsession, Teeter and DobStuff scopes is they are made with baltic birch plywood instead of MDF "particleboard" with the result they are lighter weight and more resistant to damage by dew and (in my opinion) look better than the ones using MDF construction.

I have the same exact scope and it came with a Red Dot, however I've had issues with it. I recently switched to a Rigel Quickfinder. I chose it over a Telrad for two reasons: 1. It has a built in dew shield 2. It sticks out further from the scope - if I had a Telrad, I'd have had to buy a riser. Con of the Rigel Quickfinder - it uses watch style batteries, whereas the Telrad uses regular ones. That's just been my experience so far.

I have the same scope, and I've had trouble finding items, especially in my light-polluted neighborhood. There are a couple of low-cost approaches I'm considering.

You could try an inclinometer to get altitude. Many have a magnetic base that will hold to the OTA:
Inclinometer

Another one

I've tried using my phone compass for AZ, but it's wildly inaccurate. The next step is setting circles. There are setting circles that can be printed out, laminated, and placed on the base of the telescope. They will require some finagling to fit the base of the scope. There are several threads in CloudyNights on setting circles; here are a few:

https://www.cloudynights.com/topic/5145 ... g-circles/
https://www.cloudynights.com/topic/6921 ... r-dummies/

I haven't tried printing them yet, but it's the next step.

The full-on project would be optical encoders: https://www.cloudynights.com/topic/5895 ... bsoniandsc

Here is a blog on making setting circle for a dob. I have one I am about 2/3 way done making. Hope to finish this week. I'll post when i am finished. https://andysastronomyblog.blogspot.com ... tting.html

Completed setting circle for 14 inch dob. Total diameter in 34" (setting circle says 19" but it is really 33"). Next steps are to orient telescope to Polaris and mark placement of line laser on dob base, install red line laser to dob base, and attach a leveling bubble to dob base.

Nice job. I thought about attaching a setting circle to the current base. Having a circle on a separate base that the current base feet fit to didn't occur to me. What plywood did you use? I looked at a sheet of Baltic Birch at Menards and nearly died from sticker shock.

I used a 1/2 sheet (4x4) of 3/4" birch handy-panel. . The most expensive part was getting the setting circle decal made. This is for a 14" dob.