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Seven Ways To Find Things In The Sky - Are there others?

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#76 aeajr

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Posted 01 September 2020 - 08:36 AM

It's all going to come down to a matter of definition. For instance, I would regard plate solving as just a way you calibrate goto, not another method.

 

My list would be:

 

Manual unassisted:

Visual finding: Pointing the telescope at a visible object.

Point and scan: Figuring out the position of an object you can't see, point the telescope at that position, and scan around in the eyepiece to find the object.

Star hopping: Use a sequence of star hops to find objects.

 

Manual assisted:

Equatorial setting circles

Alt-azimuth setting circles (combined with an updated computer chart with current alt-az position) - rare

Digital setting circles

 

Motorized:

Alt-azimuth goto

Equatorial goto

At one time that was true.  Celestron StarSense was an alignment tool for their GoTo systems.

 

However, technology has marched on and today you can buy The Celestron PushTo systems that are based on plate solving, not encoders. The offer it in 80 mm to 130 mm packages in refractor and reflector.  The cell phone is the camera and the computer.   It self aligns at the start of the session and then performs plate solves to give you a path to the target, plate solves to improve accuracy and plate solves to confirm the location.   

So, yes, it is a form of PushTo and I am sure there will be GoTo systems based on plate solving if they aren't out there already.  But they are not using encoders they are plate solving over and over and over during the session. 


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#77 Jon Isaacs

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Posted 01 September 2020 - 08:50 AM

This is why I separate the method of getting to the right spot from actually recognizing the object when you are there.  My experience tells me that these are two different things, two different skill sets that have to be learned.  There is finding the target and then there is recognizing you found it.

 

I have experience this many times.  I have had someone tell you he has some faint object in the eyepiece, but look as I may I can't see or or can't recognize it.   Others see and recognize it, but I don't.  Lesser eyesight or lack of understanding kept me from recognizing what was there to be seen.  In this case there was no finding method, someone else had done that.

 

 

It's very likely that if I were to look at a very difficult object someone else could see in their scope, I may not see it either.  

 

But what I am saying is, the last step in finding the object is not just knowing that it's in the eyepiece or even centered in eyepiece, the final step is knowing exactly where it is in relation to particular stars in the field.  When I know that, I can concentrate my averted vision peak on that location. 

 

That is not something one normally does when looking through someone else's scope but it's something I find necessary if I want to see the most difficult objects in my own scopes. 

 

I don't normally show other people the most difficult objects for that reason, I typically show them objects that are of interest, but some obscure galaxy that I can barely see, I reserve those for myself. 

 

Jon


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#78 hcf

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Posted 01 September 2020 - 09:40 AM

So, yes, it is a form of PushTo and I am sure there will be GoTo systems based on plate solving if they aren't out there already.  But they are not using encoders they are plate solving over and over and over during the session. 

This is a DIY GoTo system based on platesolving...

 

https://www.cloudyni...-project-ps-g2/

 

One could also think of adding platesolving to existing encoder systems to make them always accurate, not needing initial star alignment and impervious to bumping/mount movement.


Edited by hcf, 01 September 2020 - 09:57 AM.

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#79 NYJohn S

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Posted 01 September 2020 - 09:45 AM

Great thread. It's interesting to read the different techniques people use to find things. I can point the scope and land on or close to some frequently visited objects but when going after faint ones I have to start at a known location and carefully star hop to the place where the object is located. That's the only way for me to be sure I have chance of seeing the object. Then I can try everything I know to tease it out. Maybe higher magnification, a filter, shifting the place where it should be to different places in the eyepiece so I'm using different parts of my retina. There have been times I'm there for a 1/2 hour and suddenly I see the object and I really can't explain why. I love that moment when I get to the right spot and I everything matches up just right. It's like a puzzle coming together. Even if I can't see the object there's something satisfying about knowing I made it to the right place in such a vast universe.

 

I used goto for over a year and just punched in targets and logged a lot of objects. When I started star hopping I realized I was missing out on some beautiful sections of sky. If there were no objects there I had no reason to look there. With star hopping I start at a star and the hop takes me through a part of the sky I wouldn't have seen with interesting star fields, asterisms, brightly colored stars. I really enjoy that aspect of it as much as finding the object.

 

I think that's why I enjoy chasing comets. Even if they're faint barely detectable fuzzy spots, they take me through a part of the sky I may not have seen as I follow them from night to night.

 

With goto if I couldn't see an object I'd have to reverse star hop anyway to make sure I'm in the right place before giving up. Look for a nearby star on a chart and see if I can find my way to it to confirm the position. Either way having a detailed chart is necessary.

 

The other technique I use is sort of a variation of star hopping, object hopping. I do this a lot with binoculars or a small refractor. An example would be starting and M8 the Lagoon Nebula and working my way up the Milky Way stopping at M20, M22, M24, M25, M17, M16. Another example with a larger scope would be working my way through the Virgo cluster going from one galaxy to another using the layout and shapes of the galaxies to identify each other. Once you have identified one you can use it to find the others. If they're too far apart you have to do some star hopping to get to the next one. 

 

Then there's just luck. Once as I was setting up my scope at a dark site and I put the eyepiece in, focused and there was a globular cluster dead center. Now I had to figure out which one I was looking at. By looking at  the sky and seeing where the scope was pointed relative to Antares I figured out it was probably M10 and I was able to confirm it by locating M12 right next to it. So one way or another I always wind up doing some star hopping so I know where I'm pointing the scope. To me that's the key to seeing difficult objects. 

 

Recently I was viewing M33 with my 72mm refractor. Finding it wasn't hard but I wanted to try for NGC 604 - H II region inside the galaxy. I don't think Goto, setting circles or anything else would have helped here. I needed a detailed chart and I had to follow the stars to exactly where it's located. Once there It looked like a faint star right next to a foreground star. It was just on the edge of detection and came and went with averted vision. I was able to go back and confirm it with a larger scope the next night. Not as much of a challenge as it no longer looked stellar but I was thrilled to confirm that I saw it in the smaller scope.

 

So for me just pointing the scope isn't as effective (or enjoyable) as a slow deliberate star hop that puts me in exactly the right place. I guess I enjoy the journey as much as the destination.


Edited by NYJohn S, 01 September 2020 - 12:11 PM.

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#80 brentknight

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Posted 01 September 2020 - 11:19 AM

Let's not confuse getting the scope to the right spot with knowing what the target looks like or whether it will be observable with this scope under these conditions.   Those are different skills requiring different preparations and different knowledge.

 

When I say 7 ways to find things in the sky I am talking about knowing where to point the scope.  Whether you use visual cues, computerized mounts or setting circles, the goal is to get the scope pointed to the right spot.

 

Now that you are there, would you recognize it if you saw it?   Ahhh, that is another matter entirely.   If you wouldn't recognize it while star hopping, you won't recognize it with a GoTo, PushTo, Plate Solving or setting circles. 

 

All these navigation tools do is get you to the right spot so you can see it, if you can see it, if you can recognize it.  

 

Like using the GPS in your car, once you have arrived at your destination, you still need to recognize the destination.  But it should be there in front of you. 

I'm thinking of a stellar planetary nebula now.  This is an object that isn't faint, but is very small.  I have no problem seeing it because it looks just like the other stars around it.

 

I know I have the correct field because I used one of the methods discussed here to get there.  I confirm I'm in the correct field because I see a fairly bright star that I recognize off to 1 o'clock in the FOV.  If I don't have a filter that would darken all the surrounding stars more than the planetary, then how do I find it?

 

Now I'm thinking of a cluster of galaxies.  My chart shows there are 4 galaxies in the field, but I only see three (and I still don't know which three I'm seeing).  I know what that fourth galaxy looks like - it looks like a tiny faint fuzzy - pretty much just like the other three.  How would I identify the three galaxies I do see and then find the fourth one?

 

Of course that fourth galaxy might be impossible from my site, or with my equipment, but I couldn't confirm that unless I knew exactly where to look for it.  Confirming exactly where to look is the second step to finding really faint or really small targets.

 

Learning to recognize, or see these objects is a completely different skill set - I agree with you completely on that...


Edited by brentknight, 01 September 2020 - 11:35 AM.

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#81 csrlice12

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Posted 01 September 2020 - 12:35 PM

Albert, have the astronomer employee put the scope to M57...oh, and use the Pentax  10XW.


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#82 Tony Flanders

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Posted 02 September 2020 - 05:31 PM

Just to state the obvious, I should point out that phrases like "looking in the exact right spot" are unscientific -- even though I occasionally use them myself. In practice, what happens is the you have a certain degree of confidence that your telescope is pointed to a certain spot within a given range of error. Perfection does not exist in real life.

 

A number of my finding methods are only accurate within a few degrees -- at least in bright skies, where relatively few reference stars are visible. And I often don't even have 100% confidence that they're within that range. Nonetheless, I typically try those methods first, since they're more or less instantaneous. If they work, great. If not, I try something else.


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#83 Keith Rivich

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Posted 02 September 2020 - 05:40 PM

Just to state the obvious, I should point out that phrases like "looking in the exact right spot" are unscientific -- even though I occasionally use them myself. In practice, what happens is the you have a certain degree of confidence that your telescope is pointed to a certain spot within a given range of error. Perfection does not exist in real life.

 

A number of my finding methods are only accurate within a few degrees -- at least in bright skies, where relatively few reference stars are visible. And I often don't even have 100% confidence that they're within that range. Nonetheless, I typically try those methods first, since they're more or less instantaneous. If they work, great. If not, I try something else.

But one can get awfully close. When star hopping with a good set of charts one can get to within a few arc-seconds of any point in the sky, whether an object exist at that location or not. 


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#84 aeajr

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Posted 02 September 2020 - 11:06 PM

But one can get awfully close. When star hopping with a good set of charts one can get to within a few arc-seconds of any point in the sky, whether an object exist at that location or not. 

That is true.

 

My GoTo and PushTo were usually within 1/2 a degree from Center of the FOV.

 

AltAz coordinates are typically about the same, if I was careful about setting the AZ to zero at the start of the night.

 

Accuracy is better with the large AZ scale on my 12" Dob than the 6" on my Twilight 1 or the 3" on my GSkyer mount. 



#85 Tony Flanders

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Posted 03 September 2020 - 06:02 AM

Keith Rivitch said:
 

When star hopping with a good set of charts one can get to within a few arc-seconds of any point in the sky, whether an object exist at that location or not.


And aeajr responded:
 

That is true.
 
My GoTo and PushTo were usually within 1/2 a degree from Center of the FOV.


A half degree is 1800 arcseconds. So the accuracy that Keith Rivitch cites for star-hopping is roughly 500 times better by linear measure. Make that 250,000 times better if you go by the area within the circle of uncertainty.

A half degree is good enough to get an object within most telescope's field of view at the lowest possible magnification, and is therefore ample for any object that's obvious at low magnification -- barring possible issues with multiple objects in a single field of view.

It is not good enough to find objects too faint to see at low magnification, nor planetary nebulae that look completely stellar at low magnification. Nor (for those of us who do astrophotography) to place the object on the sensor of many astro-cameras.

A high-quality, carefully aligned amateur Go To system should get you within 0.1 degree of your target. Big professional scopes do even better.

For the record, one of the big problems with star-hopping in urban environments is that there are occasionally no stars visible whatsoever through the eyepiece at magnifications sufficient to see the target object.


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#86 aeajr

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Posted 03 September 2020 - 07:49 AM

We can debate accuracy all day long.   And I can argue about how someone measured the accuracy of one method vs.another.  But that doesn't matter, in my opinion.
 
The real goal is to find the target.   I don't really care if the object was dead center or slightly off to one side.  Maybe some people do, but I don't. 
 
Saturday night I was using AltAz coordinates to target my 12" Dob with my BH Zoom and my 5" Mak with a 32 mm Plossl to find my targets.  Each had about .75 degree FOV at around 60X.  I can go lower and wider with the Dob, up to a 1.75 degree FOV, but I didn't need it.   I was putting GC in the field of view, or just next to it, on both the 12" Dob and 5" Mak.  I hit Uranus and Neptune near the center of the FOV of the Dob.   
 
The variable was how accurately I aligned on Polaris at the start of the night and how carefully I set the arrow on the AZ circle as I was going to my next target.  The accuracy variable was me.  
 
The same can be said of GoTo and PushTo systems that require human alignment.  If you don't perfectly center the alignment stars the GoTo/PushTo will be off by your human error.  
 
If I can hit a target within 1/2 degree with any of these methods, that is good enough for me as it will put the target in or next to my FOV.  If I am less precise in using the setting circles or the initial alignment of the GoTo, or estimating the Telrad circles, and the target is just outside the FOV, so what?  A 1/2 degree sweep left or right gets the job done.  If I still don't see it I can resort to comparing star patterns, just like the star hopper would.  But my starting point for making that comparison is within 1/2 degree of the target.
 
Whether the GoTo is accurate to .5 degrees or .1 degrees is an interesting engineering discussion, but for most people, irrelevant.  The target is in the field of view in a low to medium power eyepiece.  We are not talking about a 5 meter scope in an observatory, we are typically talking about 3"-16" scopes used by hobbyists to find things that are within the visual capability of their scopes. 
 
Star hopping, buy nature, is a best approximation process based on the skill of the person.  You are using an informational feedback loop to adjust and correct by comparing the star patterns to your expected position of your target.   You can name any level of precision you like, but the fact is that you are approximating the location, then using star patterns, if you can see enough stars, to adjust.  Shall we call star hopping a form of plate solving?  In fact that is what it is. 
 
Believe me, I enjoy a good debate and this discussion has raised some very interesting points. And I have learned a lot.  But the bottom line is that there are many ways to find your targets. They all work.
 
If you have one method that works for you, great!  I want to thank you for sharing your experience.  We all benefit by your comments.
 
If you are struggling with your current method, or are not aware of one of the other methods, you may wish to try something new.  I hve used 5 of the 7 I listed.

 

Eventually you will find the one(s) that you like and that will be what you will use. There is no mandate or rule that says you have to use any particular method.
 
Whether the accuracy level is .1 degrees or .5 degrees is interesting but, in my opinion, not a big deal.  These will be driven by the skill level of the user and will likely improve over time as they gain experience with that method.  How close you hit will be more about your  skill and precision with which you execute. 
 
Clear skies! waytogo.gif


Edited by aeajr, 03 September 2020 - 08:03 AM.

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#87 NYJohn S

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Posted 03 September 2020 - 07:50 AM

Keith Rivitch said:
 


And aeajr responded:
 


A half degree is 1800 arcseconds. So the accuracy that Keith Rivitch cites for star-hopping is roughly 500 times better by linear measure. Make that 250,000 times better if you go by the area within the circle of uncertainty.

A half degree is good enough to get an object within most telescope's field of view at the lowest possible magnification, and is therefore ample for any object that's obvious at low magnification -- barring possible issues with multiple objects in a single field of view.

It is not good enough to find objects too faint to see at low magnification, nor planetary nebulae that look completely stellar at low magnification. Nor (for those of us who do astrophotography) to place the object on the sensor of many astro-cameras.

A high-quality, carefully aligned amateur Go To system should get you within 0.1 degree of your target. Big professional scopes do even better.

For the record, one of the big problems with star-hopping in urban environments is that there are occasionally no stars visible whatsoever through the eyepiece at magnifications sufficient to see the target object.

I think this is probably one of the reasons why people look for different methods of finding things. I have no experience observing from skies any brighter than Bortle 5 so I enjoy star hopping. As I was reading the thread I realized my XT8i is at a dark site and the intelliscope controller is home in a box with the battery removed. I just don't think about using it anymore.

 

I observe with Ed - aeajr quite often and I know the sky where he lives is quite a bit brighter than where I live. He's been resourceful and added AZ scales to his scopes. He's even gone on to teach others that are getting started to do the same and work with an angle gauge to find objects.

 

I came across someone that he taught the technique to at a local park one night. He was was out there finding things on his own and enjoying himself. We shared some views and worked together a little. It was good to see someone just getting started enjoying the night sky and seeing the sense of accomplishment on his face when he located another object. These were bright objects that showed easily at low power but that's probably the type of objects most of us start with anyway.

 

John


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#88 aeajr

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Posted 03 September 2020 - 08:51 AM

One method that seems to have fallen into general disuse is the manual setting circles on Equatorial mounts.   Perhaps someone in this thread is using this and I missed it just now as I skimmed over the discussion.

 

I belong to an astronomy club of about 80 members.  I asked if anyone was using these setting circles.  Two said they had in the past, many years ago, but no longer.

 

A couple of the star hoppers have EQ mounts but they don't use the setting circles at all. 

 

It seems that those setting circles on the EQ mounts have fallen out of favor.    

 

Anyone here actively using EQ mount setting circles to find your targets?  And, just to be clear, I don't mean a Goto EQ mount.


Edited by aeajr, 03 September 2020 - 08:53 AM.

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#89 Mitrovarr

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Posted 03 September 2020 - 09:19 AM

No setting circles here. I've used then before, but don't anymore. I think they're dead because for the most part, if you are spending enough to get an equatorial mount of sufficient quality to get setting circles you can actually use, you probably have goto.
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#90 brentknight

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Posted 03 September 2020 - 10:13 AM

Keith Rivitch said:
 


And aeajr responded:
 


A half degree is 1800 arcseconds. So the accuracy that Keith Rivitch cites for star-hopping is roughly 500 times better by linear measure. Make that 250,000 times better if you go by the area within the circle of uncertainty.

A half degree is good enough to get an object within most telescope's field of view at the lowest possible magnification, and is therefore ample for any object that's obvious at low magnification -- barring possible issues with multiple objects in a single field of view.

It is not good enough to find objects too faint to see at low magnification, nor planetary nebulae that look completely stellar at low magnification. Nor (for those of us who do astrophotography) to place the object on the sensor of many astro-cameras.


A high-quality, carefully aligned amateur Go To system should get you within 0.1 degree of your target. Big professional scopes do even better.

For the record, one of the big problems with star-hopping in urban environments is that there are occasionally no stars visible whatsoever through the eyepiece at magnifications sufficient to see the target object.

I think the big deceit with Go2 (and to some degree the circles and gauges) is the belief that they are sufficient to find all the objects within reach of the telescope.  Having a database of 40K objects in your Go2 computer is really pretty useless because only about 400-500 of them can be seen in average conditions with average equipment without additional steps.  The accuracy is just not there.  But you can increase the object count (and variety) significantly if you use additional methods within that .5° field.

 

I get it - not everybody cares about this.  But some observers who start out with just the WOW objects will eventually want a few challenges mixed in.

 

EDIT: In case anyone does not realize it...0.5° is the size of the full Moon.

 

Clear Skies everyone - the dark of the Moon approaches...


Edited by brentknight, 03 September 2020 - 10:30 AM.

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#91 NYJohn S

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Posted 03 September 2020 - 10:14 AM

The think last person I remember using setting circles had a Questar on a Tristand. I believe once it was setup it would also track the object. 


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#92 Tony Flanders

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Posted 03 September 2020 - 10:42 AM

Anyone here actively using EQ mount setting circles to find your targets?  And, just to be clear, I don't mean a Goto EQ mount.


In other threads, the user Andrekp has stated that he grew up using EQ setting circles, and continues to do so. And I certainly know other people who do fairly routinely.

I have done it a few times just to prove that it's possible, but on the whole I find that it requires far more effort than star-hopping. Among other things, I'm usually pretty sloppy about my polar alignments, and using setting circles requires really good polar alignment.

A technique I have used more often, when moving from one object to another through an EQ scope, is to note the offsets between the objects in RA and Dec, and then measure them off with the setting circles. Within small regions, this is accurate even if your polar alignment is way off.

 

It's interesting to see this method listed as an afterthought, in view of the fact that in the 60s and earlier it was pretty much the gold standard. The setting circles on the giant reflectors of the early 20th century are a sight to see. They must be at lest 10 feet across!


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#93 csrlice12

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Posted 03 September 2020 - 11:18 AM

8.  Dumb luck.


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#94 Jon Isaacs

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Posted 03 September 2020 - 11:57 AM

We can debate accuracy all day long.   And I can argue about how someone measured the accuracy of one method vs.another.  But that doesn't matter, in my opinion.

The real goal is to find the target.   I don't really care if the object was dead center or slightly off to one side.  Maybe some people do, but I don't.

Saturday night I was using AltAz coordinates to target my 12" Dob with my BH Zoom and my 5" Mak with a 32 mm Plossl to find my targets.  Each had about .75 degree FOV at around 60X.  I can go lower and wider with the Dob, up to a 1.75 degree FOV, but I didn't need it.   I was putting GC in the field of view, or just next to it, on both the 12" Dob and 5" Mak.  I hit Uranus and Neptune near the center of the FOV of the Dob.

 

 

Ed:

 

The goal is to find the target.  When you are talking about 1/2 degree pointing accuracy, an object is not just slightly off to one side, it takes a 1 degree TFoV for it.

 

The fact that you don't care, I am suggesting maybe you should care.  Uranus and Neptune are binocular objects, easy.  Putting a globular next to the field or at the edge, sure, for a bright globular but there's a lot of globulars that are diffuse and barely visible at under optimal conditions.  Knowing where it is, in the star field, it's a key actually seeing.

 

I suspect that 15 years down the road, when you've been doing this a while, you will be paying more attention to some of these details and will not be satisfied with merely putting an object somewhere in the field of view.  Star hopping in the main eyepiece or more accurate GOTO/DSCs will become part of your the tools you use.

 

When Kevin says he can point to any spot in the sky within a few arc-seconds using charts, that's pretty dramatic but there's a reason he's working at a small fraction of a degree, it's because that's what it takes sometimes.

 

These techniques, these are about finding the most difficult objects, objects that are not visible at low magnifications, objects that are barely visible at any magnification.  

 

You might just give up as unseeable but it's not time yet. 

 

Jon


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#95 aeajr

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Posted 03 September 2020 - 12:30 PM

Ed:

 

The goal is to find the target.  When you are talking about 1/2 degree pointing accuracy, an object is not just slightly off to one side, it takes a 1 degree TFoV for it.

 

The fact that you don't care, I am suggesting maybe you should care.  Uranus and Neptune are binocular objects, easy.  Putting a globular next to the field or at the edge, sure, for a bright globular but there's a lot of globulars that are diffuse and barely visible at under optimal conditions.  Knowing where it is, in the star field, it's a key actually seeing.

 

I suspect that 15 years down the road, when you've been doing this a while, you will be paying more attention to some of these details and will not be satisfied with merely putting an object somewhere in the field of view.  Star hopping in the main eyepiece or more accurate GOTO/DSCs will become part of your the tools you use.

 

When Kevin says he can point to any spot in the sky within a few arc-seconds using charts, that's pretty dramatic but there's a reason he's working at a small fraction of a degree, it's because that's what it takes sometimes.

 

These techniques, these are about finding the most difficult objects, objects that are not visible at low magnifications, objects that are barely visible at any magnification.  

 

You might just give up as unseeable but it's not time yet. 

 

Jon

Good points Jon. 

 

All of these tools and techniques are available to fine tune the position and identify the target regardless of whether I am star hopping, GoTo, PushTo, or setting circles.  I presume plate solving would have me in the right spot, but I have no experience with its accuracy.  



#96 Keith Rivich

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Posted 03 September 2020 - 01:20 PM

Ed wrote in part:

"The real goal is to find the target.   I don't really care if the object was dead center or slightly off to one side.  Maybe some people do, but I don't."

 

I believe if you replace "target" with "coordinate" you hit a little closer to home. Getting to a coordinate and seeing the target use slightly overlapping but very different skill sets. 


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#97 Dave Mitsky

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Posted 03 September 2020 - 09:58 PM

In other threads, the user Andrekp has stated that he grew up using EQ setting circles, and continues to do so. And I certainly know other people who do fairly routinely.

I have done it a few times just to prove that it's possible, but on the whole I find that it requires far more effort than star-hopping. Among other things, I'm usually pretty sloppy about my polar alignments, and using setting circles requires really good polar alignment.

A technique I have used more often, when moving from one object to another through an EQ scope, is to note the offsets between the objects in RA and Dec, and then measure them off with the setting circles. Within small regions, this is accurate even if your polar alignment is way off.

 

It's interesting to see this method listed as an afterthought, in view of the fact that in the 60s and earlier it was pretty much the gold standard. The setting circles on the giant reflectors of the early 20th century are a sight to see. They must be at lest 10 feet across!

I've occasionally used the setting circles on the equatorial mounts of the 12.5" Cave Astrola Newtonian and the 17" classical Cassegrain at the Naylor Observatory, both of which are large enough to be fairly accurate.  The two telescopes, of course, are both permanently mounted on piers. 

 

The offset method that Tony mentions is easier to use and I would employ it more often.

Both telescopes are equipped with Argo Navis units nowadays so I use them instead or do simple star-hops with Telrads and finder scopes for easy-to-locate objects.


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#98 Starman1

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Posted 04 September 2020 - 05:23 PM

I have learned of seven ways to find specific targets in the sky with my telescope and was wondering if there are others that I have not come across.
 
Visual

  • What you can see with your eyes alone when you look up 
  • Star Hopping – Naked eye and optically assisted but still visual

Computer Assisted

  • PushTo - encoders
  • GoTo - encoders
  • Plate Solving - camera based

Setting Circles

  • Equatorial Alignment - Right Ascension/Declination
    Altitude Azimuth Alignment

Each has its advantages and its challenges, so I have learned to use 5 of them.
 
I have not tried RA/DEC setting circles because I don't have an equatorial mount but I could polar align my ETX scopes.   And I have not used plate solving because I am not using a camera at this time.
 
But are there others?   Another approach?
 
What's your favorite?
 
Edit:  I was not thinking of scanning for discovery, but I guess that would apply.  It just isn't a way to find specific targets.

Yes.

1) find a star along a similar declination to the west of the object, center the star and let the sky drift the object into the field of view after a time.

2) Dead pointing.  I can put M57, M13, M5, M15 and many others in the field of an eyepiece without hopping to it.  It's assisted by a Telrad, but it isn't really star hopping since the object is in the field when I go to the eyepiece.

Some people call that "triangulation", though I usually use lines, not triangles.


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#99 brentknight

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Posted 04 September 2020 - 09:57 PM

At this point, I'm just curious how many people would be willing to take the extra effort to look for those challenging targets that don't immediately pop out of the field after using one of the location methods we've talked about?  Or would you be satisfied that you at least gave it a try, but that even if you did find it, it wouldn't have been worth it...


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#100 aeajr

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Posted 04 September 2020 - 11:36 PM

Ed wrote in part:

"The real goal is to find the target.   I don't really care if the object was dead center or slightly off to one side.  Maybe some people do, but I don't."

 

I believe if you replace "target" with "coordinate" you hit a little closer to home. Getting to a coordinate and seeing the target use slightly overlapping but very different skill sets. 

You can use whatever terms you like.  My goal is not to find a coordinate, it is to find the object I wish to see which I refer to as the target. 

 

When I identify the target, the object I want to see, then I use one of these methods to get it into the eyepiece so I can observe it.  That is the goal.




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